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					Project Number 05912                                    Page 1 of 77




                Project Number 05912
R.I.T. 175th Anniversary Motorcycle
Customization and Customization Kit
           Documentation
                       Alexandra Collier – ME
                          Lee Gagne – ME
                       Jonathan Howard – ME
                         John Johnson – IE
                          Jeremy Rank – IE
                       Anthony Rounding – IE
                          Curtis Vana - EE

         Rochester Institute of Technology,
                  Rochester, NY
               Faculty Mentor: Dr. James Taylor
             Faculty Coordinator: Prof. Paul Stiebitz
Project Number 05912                                                                                                  Page 2 of 77


Table Of Contents

TABLE OF CONTENTS ................................................................................................. 2
INTRODUCTION............................................................................................................. 5
   HARLEY-DAVIDSON MOTORCYCLES ............................................................................... 5
   R.I.T. 175TH ANNIVERSARY ............................................................................................. 5
   PROJECT NUMBER 05912 ................................................................................................. 6
   CHOPPER RESEARCH ........................................................................................................ 7
NEEDS ASSESSMENT .................................................................................................... 8
   DEVELOPMENT OF THE NEEDS ASSESSMENT ................................................................... 8
   PROJECT MISSION STATEMENT (QUALITATIVE) ............................................................... 9
   NEEDS ASSESSMENT PYRAMID (QUANTITATIVE)........................................................... 14
CONCEPT DEVELOPMENT ....................................................................................... 17
   INTRODUCTION .............................................................................................................. 17
   GAS TANK ...................................................................................................................... 17
   HANDLEBARS/ CONTROLS ............................................................................................. 18
   RIDE HEIGHT ................................................................................................................. 18
   TIRE ............................................................................................................................... 18
   SWING ARM .................................................................................................................... 18
   WHEEL DESIGN .............................................................................................................. 19
   BRAKES ......................................................................................................................... 19
   DRIVE ............................................................................................................................ 19
   WHEEL HUBS ................................................................................................................. 19
   HEADLIGHT.................................................................................................................... 20
   AIR FILTER .................................................................................................................... 20
   MODIFY RAKED TREE .................................................................................................... 20
   EXHAUST ....................................................................................................................... 21
   SEAT .............................................................................................................................. 21
   ELECTRICAL ................................................................................................................... 21
   CONVERSION KIT ........................................................................................................... 22
   CONCEPT DRAWING ....................................................................................................... 22
FEASIBILITY ANALYSIS............................................................................................ 24
   INTRODUCTION .............................................................................................................. 24
   GAS TANK ..................................................................................................................... 24
   HANDLE BARS / CONTROLS ........................................................................................... 25
   RIDE HEIGHT ................................................................................................................. 26
   TIRE ............................................................................................................................... 26
   SWING ARM ................................................................................................................... 28
   WHEEL DESIGNS ............................................................................................................ 28
   WHEEL HUBS ................................................................................................................. 28
   BRAKES ......................................................................................................................... 29
   DRIVE ............................................................................................................................ 29
   HEADLIGHT.................................................................................................................... 30
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   AIR FILTER ..................................................................................................................... 31
   MODIFY RAKED TREE .................................................................................................... 31
   EXHAUST ....................................................................................................................... 33
   SEAT .............................................................................................................................. 33
   ELECTRICAL ................................................................................................................... 34
   CONVERSION KIT ........................................................................................................... 35
SPECIFICATIONS......................................................................................................... 37
   INTRODUCTION .............................................................................................................. 37
   DESIGN OBJECTIVES ...................................................................................................... 37
   DESIGN SPECIFICATIONS ................................................................................................ 37
     Gas Tank ................................................................................................................... 37
     Handlebars / Controls............................................................................................... 38
     Ride Height ............................................................................................................... 38
     Tires and Wheels ....................................................................................................... 38
     Swing Arm ................................................................................................................. 38
     Wheel design ............................................................................................................. 38
     Wheel Hubs ............................................................................................................... 39
     Drive ......................................................................................................................... 39
     Modify Raked Tree .................................................................................................... 39
     Exhaust ...................................................................................................................... 40
     Seat ............................................................................................................................ 40
     Electrical ................................................................................................................... 40
ANALYSIS AND SYNTHESIS ..................................................................................... 41
   INTRODUCTION .............................................................................................................. 41
   INCREASED LIGHTING .................................................................................................... 41
   HANDLEBAR DESIGN ..................................................................................................... 42
   ELECTRONICS................................................................................................................. 44
     Specifications of feasible system:.............................................................................. 44
     Possible General System Designs:............................................................................ 44
     CKP TEST:................................................................................................................ 47
     Digital controller Algorithm: .................................................................................... 51
     Materials:.................................................................................................................. 52
     Digital Controller: .................................................................................................... 53
     LED Drivers: ............................................................................................................ 53
     Voltage Regulator: .................................................................................................... 55
   TRIPLE CLAMP DESIGN .................................................................................................. 56
   SWING ARM ................................................................................................................... 61
   WHEEL DESIGN .............................................................................................................. 62
   WHEEL HUB................................................................................................................... 64
   DRIVE ............................................................................................................................ 65
APPENDIX A .................................................................................................................. 67
APPENDIX B .................................................................................................................. 73
APPENDIX C .................................................................................................................. 74
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REFERENCES ................................................................................................................ 77
Project Number 05912                                                            Page 5 of 77


Introduction

Harley-Davidson Motorcycles
21-year old William S. Harley and 20-year old Arthur Davidson produced their first
motorcycle in 1903. The bike was built in a 10 x 15 foot wooden shed with the words
“Harley-Davidson Motor Company” crudely written on the door (5). Since 1903, Harley-
Davidson has produced the most recognizable motorcycles in the world. Today people
can tour any of the three Harley-Davidson factories and catch a glimpse of some of the
most technologically advanced motorcycle manufacturing process in the world. This
seems a long way from the meager beginnings Harley-Davidson had in a wooden shed
and the company continues to grow. For the past nineteen years Harley-Davidson has
reported record revenues and earnings. During 2004, the motorcycle industry itself
cruised to its 12th straight year of growth. The motorcycle industry is growing so rapidly
that within the past four years 24% more units were sold than in the entire previous
decade (1990-1999) (2). Motorcycling is more mainstream today than ever before and
the numbers prove it. Many motorcycle owners feel no other motorcycle has the look,
sound or feel of a Harley-Davidson.


R.I.T. 175th Anniversary
The Rochester Institute of Technology will be celebrating its 175th anniversary in 2005.
A parade will be held on April 30th of 2005 to honor and celebrate the school’s rich
history. Each of the individual colleges of R.I.T. will be entering a float / presentation
containing a past, present and future theme. The college of engineering wanted to enter a
technical and unique float / presentation that incorporated each of the engineering
disciplines. A proposal to convey the past, present, and future theme of the college of
engineering float / presentation was put together by Dr. James Taylor of the Industrial
and Systems Engineering department. The proposal incorporated the popular phenomena
of motorcycles and the multidisciplinary senior design course. The “past” would be
represented by alumni and friends of alumni riding vintage motorcycles in the parade.
The “present” would be represented by a custom chopper built by engineering students in
senior design. Children of the R.I.T. faculty, staff and community would ride pedal bikes
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in the parade to represent the “future” of the Rochester Institute of Technology. A
multidisciplinary senior design team would be designing and manufacturing a custom
chopper motorcycle for the parade. The faculty of R.I.T. liked the proposal and a
connection between R.I.T. and Santa Cruz Harley-Davidson was revealed. Santa Cruz
Harley-Davidson is one of the largest and most recognized Harley-Davidson dealerships
in the world. The dealership provides bikes, parts, and accessories to Harley-Davidson
enthusiasts. Santa Cruz Harley-Davidson even has a museum displaying vintage
motorcycles, pictures and memorabilia to the people of California and its visitors. The
owner of Santa Cruz Harley-Davidson, Mike James, was kind enough to donate two
brand new 883C Harley-Davidson Sportster Motorcycles to R.I.T. and the senior design
course.


Project Number 05912
Our multidisciplinary senior design team was put together to design and develop a
custom chopper from a stock Harley-Davidson 883C Sportster motorcycle. The Sportster
is Harley-Davidson’s least expensive model. It provides people the opportunity to own a
Harley-Davidson motorcycle for less than seven thousand dollars. Harley-Davidson
makes around five hundred Sportsters each day within their manufacturing facilities and
still has problems keeping up with customer orders. While converting the 883C Sportster
into a custom chopper motorcycle, our senior design team will be simultaneously
developing a custom motorcycle conversion kit. The kit will contain documentation of
the changes made to the stock 883C Sportster Harley-Davidson. Santa Cruz Harley-
Davidson could potentially produce, market, and sell these 883C Sportster / Custom
Chopper conversion kits. The conversion kit would provide potential customers the
opportunity to own a low cost custom chopper motorcycle that carries the Harley-
Davidson name. There are a number of custom chopper kits on the market right now.
Each of the current kits provides the customer the opportunity to build and develop their
own custom chopper motorcycle. None of the kits are currently produced out of stock
Harley-Davidson motorcycles. This means none of the custom choppers on the market
right now carry the Harley-Davidson name.
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Chopper Research
A chopper motorcycle refers to a radically customized motorcycle. A chopper is created
by removing or “chopping” off unnecessary components from a motorcycle. Items like a
windshield, large fenders, big headlights, crash bars, and big seats are eliminated from
the motorcycles design. Until the late 1960s and early 1970s choppers had made little
impact in the motorcycle world. The release of the legendary movie Easy Rider in 1969
began a whole new motorcycle movement. Motorcycle enthusiast wanted a bike like the
one ridden by Peter Fonda in the movie; they wanted a chopper (7). Backyard mechanics
and motorcycle designers began to lower the motorcycles suspension and replace the
standard big front wheel, head light and fuel tank with smaller ones. As the front tire
became smaller the rear tire became larger and larger. Bikers started raking the front end
of their choppers so the angle of the fork to the ground began to decrease. The
handlebars on choppers are often raised higher than standard handlebars and are referred
to as ape hangers. The chopper style made for a bike that was unique and tailored to the
individual rider. It is important to remember that each individual motorcycle rider or
designer decided what needed to be changed to his or her motorcycle to create a custom
chopper.
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Needs Assessment

Development of the Needs Assessment
On December 3rd our senior design team was introduced to one another. The team was
introduced to the project and the group members were instructed to begin researching
chopper motorcycles. Our team researched magazines, websites, and even television
programs involving motorcycle customization and modification. The team gathered
ideas of what modifications needed to be made to a standard 883C Sportster Harley-
Davidson to create a “custom chopper look”. The team developed a preliminary list of
order qualifiers that created an excellent starting point for our first conversation with
Mike James, the owner of Santa Cruz Harley-Davidson.
      The team comprised a list of order qualifiers and proposed the changes to Mike
       James during a teleconference on December 10th, 2004. The “top level” list of
       potential modification ideas was comprised from research done by the team and
       the teams’ previous knowledge of motorcycles.
           o Front end of the bike shall change
           o Rear end of the bike shall change
           o Sheet metal of the bike shall change
           o Seat of the bike shall change
           o Paint on the bike shall change
           o Electronics on the bike shall change
           o Ride height of the bike shall change
           o Custom conversion kit shall be “bolt on”
The senior design team was able to convey our understanding of the changes that needed
to be made to a stock 883C Sportster Harley-Davidson to Mike James and his custom
designer Bob Davis. During the teleconference the team received great feedback that
aided in the development of the team’s needs assessment. Mike James and Bob Davis of
Santa Cruz Harley-Davidson seemed very excited about the project. They understood
and recognized that nothing like this project (a low cost custom chopper that carries the
Harley-Davidson name) was on the market right now. Our senior design team was able
to develop a complete list of order qualifiers after the teleconference with Santa Cruz
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Harley-Davidson. Each of the top-level order qualifiers involved a number of steps and
design changes. These numerous changes built deeper and more defined versions of the
initial needs assessment. As one change was made numerous other changes would be
recognized.
Project Mission Statement (Qualitative)
Product        A summary description of what the product is.
(Project)      A multidisciplinary senior design team will be designing and developing
Description    custom choppers from stock Harley-Davidson 883C Sportsters. The
               team will simultaneously develop the documentation for a
               Sportster/Chopper conversion kit that could potentially be marketed and
               sold by Harley-Davidson or motorcycle parts distributors.
Scope          A description of what features the product shall contain and/or what
Limitations    constraints are placed on the project.
                      Santa Cruz Harley-Davidson has donated two Harley-Davidson
                       883C Sportsters.
                      Funds to design and develop the conversion from a stock
                       Sportster to a custom chopper should not exceed nine thousand
                       dollars per bike.
                      Sheet metal on bikes shall change
                      Wheels on bikes shall change
                      Seats on bikes shall change
                      Front end on each bike shall change
                      Rear end of each bike shall change
                      Swing arm on each bike shall change
                      Electronics on each bike shall change
                      Paint on each bike shall change
                      At least one bike (Tiger 175th Chopper) shall be finished and
                       operable on April 30th for the Rochester Institute of Technology
                       175th anniversary parade.
                      Kit documentation completed by end of Senior Design Two.
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Stakeholders   A list of all groups that will in some way interact with the product.
                      Multidisciplinary senior design team
                      Dr. James Taylor – Faculty Sponsor / Project Leader
                      Rochester Institute of Technology
                          -   College of Engineering Parade Display
                          -   Permanent Engineering Building Display
                      Santa Cruz Harley-Davidson
                          -   Mike James (President)
                          -   Bob Davis (Custom Department)
                      Auction participants (in order to generate funds by selling one of
                       the custom Sportsters)
Key Business A discussion of financial measures of success, such as profit, return on
Goals (CFPs)   investment, payback period, net present value, etc. These are big picture
               statements that address why there is a project in the first place.
                      Provide a low cost custom chopper that will carry the Harley-
                       Davidson name. There are a number of chopper kits that exist
                       within the market right now. When the kits are put together and
                       the finished bike is assembled it does not carry the Harley-
                       Davidson name. By providing a kit to convert a Harley-Davidson
                       into a chopper, the Harley Davidson name is carried over to the
                       custom chopper.
                      Provide the everyday Harley-Davidson owner with the
                       opportunity to obtain a custom chopper.
                      Provide a custom chopper in the ten to fifteen thousand dollar
                       range; this goal would make our proposed chopper conversion
                       cheaper than the current low end kit bike that does not carry the
                       HD name.
                      Provide a “bolt on” kit that could be assembled by the average
                       mechanic.
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Financial     Detailed financial analysis that itemizes development costs,
Analysis      manufacturing costs, sales volume, cash flow, etc. This will be a more
              detailed analysis that can help guide the design and be a vehicle for
              comparison among alternatives.
              The cost constraints listed hear do not pertain to the actual custom
              chopper prototype bikes that our team will be producing. The costs listed
              pertain to the kit documentation that will be put together for the end of
              Senior Design Two. The senior design team will be producing high end
              and high cost prototypes of the finished kit product.
              Tiger Copper Preliminary Budget- Per Bike Costs
                      Sheet Metal
                          -   Gas Tank ($400)
                          -   Gas Cap ($100)
                          -   Petcock ($80)
                          -   Chin Fairing ($110)
                          -   Front Fender ($200)
                          -   Rear Fender ($260)
                      Wheels/Tires
                          -   Wheel Blanks - front and back ($400)
                          -   Valve Stems ($12)
                          -   Front Tire ($135)
                          -   Rear Tire ($230)
                      Front End
                          -   Fork Tubes ($280)
                          -   Springs ($100)
                      Controls
                          -   Handlebars ($100)
                          -   Risers ($200)
                          -   Mirrors ($100)
                          -   Grips ($230)
                          -   Headlight ($100)
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                      Misc.
                          -    Paint ($1000)
                          -    Seat ($500)
                          -    Exhaust ($500)
                          -    Swing Arm ($1200)
                          -    Tools ($300)
                          -    Lift ($595)
                          -    Leather Jacket ($250)
                          -    Raw Materials ($1000)
                          -    Finishing ($500)
                          -    Parts Production (Brinkman Lab)
                          -    Marketing Analysis potentially preformed by Santa Cruz
                               Harley Davidson
Preliminary   A description of the main group of customers. The term ‘customer’ is
Market        loosely defined as those who will be the primary recipient of your work.
              In some cases, this may only by your sponsor.
              The Harley-Davidson owner who desires a custom motorcycle at a
              relatively low cost of ten to fifteen thousand dollars.
Secondary     A description of other customer groups that could be reached with minor
Market        modifications of the product design.
              Motorcycle parts distributors could market and sell the 883C Sportster /
              Custom conversion kit.
Order         A list of critical performance parameters that make the product (project)
Qualifiers    interesting enough for a customer to consider the product (project) for
              purchase (sponsorship). If any of these attributes are missing, then the
              product (potential Project deliverables) will not even be considered.
                      Shall change rear end of bike
                          o Rear tire shall be between 180 mm and 220 mm
                          o Shall change swing arm
                          o Custom rear wheel shall be produced in Brinkman Lab
                          o Shall modify drive belt cover
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                      Shall change front end of bike
                           o Rake angle shall change (triple tree)
                           o Handle bars shall change
                           o Custom front wheel shall be produced in Brinkman Lab
                      All sheet metal on bikes shall change
                           o Fuel tank shall change
                           o Front and rear fender shall change
                           o Metal covers shall change
                      Seat shall change on both bikes
                      Electronics shall change on both bikes
                      Paint shall change
                      Tiger 175th Chopper Bike shall be operable
Order          A list of critical performance parameters that are likely to lead the
Winners        customer to choose your product over that of the competition. These
               attributes differentiate your product (project) from the average bear.
                      Exhaust should change
                           o Possibly exit exhaust on left side of bike
                      Cases should be modified
                      Should change drive system to a chain from the existing belt
                      Custom calipers and/or rotors should be implemented
                      Should upgrade control cables
                      Should modify controls
                           o Grips
                           o Pegs
                      Should upgrade existing gages
                      An LED brake light should be implemented
                      Should change signal lights
                      Should change existing mirrors
Innovation     Features, performance levels, and technologies in the vase product
Opportunities design that could be significantly improved in an effort to product
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                significantly greater sales (or utilization of the project deliverables).
                        All parts in the kit could actually be produced
                        Nitrous could be added to the bike
                        Wheelie bar could be added
                        Could add a 340 mm rear tire
                        Could upgrade engine
                        Increase the rakes to an extreme amount
Other           Other relevant information that impacts the project. Feel free to add new
                categories.
                Bike must be aesthetically pleasing.


Needs Assessment Pyramid (Quantitative)
A multidisciplinary senior design team will be designing and developing custom
choppers from stock Harley-Davidson 883C Sportsters. The team will simultaneously
develop the documentation of a Sportster / Chopper conversion kit that could potentially
be marketed and sold by Harley-Davidson or motorcycle parts distributors.


Level (1) – Qualifiers
   Technological Attributes
        o Shall Change Rear End of Bike
                  Rear tire shall be between 180mm and 220mm.
                  Custom rear wheel shall be machined from a blank in the Brinkman
                   Lab
                            Purchase or fabricate hub.
                  Modify the swing arm.
                            New shocks shall be implemented
                            The drive train will need to be modified so that the secondary
                             drive is in line.
                                 o The right side transmission cover (case) will need to be
                                     modified or redesigned in order to accommodate the
                                     shifting of the front pulley or sprocket.
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                         Modify brake caliper position to line up with rotor.
       o Shall Change Front End of Bike
                 Rake angle shall change via the triple tree (modify triple tree
                  geometry).
                         Fork length will be modified to match the change in rake angle.
                 Custom front wheel shall be machined from a blank in the Brinkman
                  Lab.
                         Purchase or fabricate hub.
                 Custom handlebars shall be fabricated and/or purchased.
                 Modify brake caliper position to line up with rotor.
       o All sheet metal on the bike shall change
                 Custom fuel tank shall be purchased and possibly modified.
                 Custom fenders shall be purchased and possibly modified.
       o Custom seat shall be purchased to fit 883C Sportster; if custom seat does not
           fit to seat pan a new seat pan will need to be fabricated.
       o Electronics shall change
                 Variable Intensity Light added to bike
                         Adding hidden lights / similar to neon under glow kit
       o   Paint shall change
                 Change paint on all sheet metal of each bike
   Performance Attributes
       o At least one bike (Tiger 175th Chopper) shall be finished and fully operable on
           April 30th for the Rochester Institute of Technology 175th anniversary parade.
                 The 175th Chopper shall be operable with all order qualifiers and
                  technical attributes implemented.
       o The second bike (Tiger 175th Chopper replica) shall be finished and fully
           operable by the end of Senior Design Two.
                 The 175th Chopper shall be operable with all order qualifiers technical
                  attributes implemented.
   Schedule Attributes
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        o At least one bike (Tiger 175th Chopper) shall be finished and fully operable on
           April 30th for the Rochester Institute of Technology 175th anniversary parade.
        o The second bike (Tiger 175th Chopper replica) shall be finished and fully
           operable by the end of Senior Design Two.
   Economic Attributes
        o Provide the everyday Harley owner with the opportunity to obtain a custom
           chopper.
        o Provide a custom chopper in the ten to fifteen thousand dollar range; this goal
           would make our proposed chopper conversion cheaper than the current low-
           end kit bike that does not carry the HD name.
        o Funds used to design and develop the conversion from a stock 883C Sportster
           to a custom chopper should not exceed nine thousand dollars per bike.


Level (2) – Winners
       Technological Attributes
           o Exhaust should change
                      Exit exhaust on left side of bike
           o Cases should be modified
                      Customize (anodize, engrave)
           o Should change drive system to a chain from the existing belt
           o Custom calipers and/or rotors should be implemented
           o Should upgrade control cables
           o Should modify controls
                      Grips
                      Pegs
           o Should upgrade existing gages
           o An LED brake light should be implemented
           o Should change signal lights
                      Should change existing mirrors
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Concept Development

Introduction
After the completion of the Needs Assessment, the team began to work on the Concept
Development. The Needs Assessment was used as a reference for any and all areas of
change. The team brainstormed and obtained different ideas on how to change parts of
the bike to achieve the goals that had been set forth in the Needs Assessment. In this
brainstorming session, no idea was too ludicrous; team members reserved all judgment
until the Feasibility Analysis. The teams design ideas were obtained from research,
personal knowledge and conversations with Mike James and Bob Davis of Santa Cruz
Harley-Davidson.


Gas tank
       Remove traditional Sportster tank
       Replace with radical new tank design
            o Custom design
                      Incorporate RIT Tiger into tank
                      Make a flowing tank
                      Make tank with sharp edges to resemble tiger claws
            o Custom fabricate
                      Look to see if metal working students at RIT could do this
                      Send off to a custom fabricator
                      Talk to Orange County Choppers to discuss tank ideas
            o Custom paint
                      Hire custom painter
                      Have powder coated
                      Have Industrial Designers paint
       Replace tank with commercially available tank
       Replace tank with commercially available tank with a decorative sheet metal
        “skin” on it to achieve custom look
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Handlebars/ Controls
          Clean up controls for a sleeker look
          Hide controls as much as possible inside of handle bars
          Change the shape for a look befitting a chopper not a dirt bike
          Use a handlebar or twist grip clutch (as seen on TV, Exile Cycles)
          Use a suicide shifter in place of a standard shifter
          Create custom foot pedals
          Use biomechanics to determine changes


Ride Height
          Lower the height of the bike for squatter, more aggressive stance
              o Shocks can be shortened to lower bike
                         Replace shocks to conceal the springs
          Change fork length to accommodate the lowering of the bike
          Remove shocks and make the bike a rigid
          Lowering blocks – spacers that move the rear shock’s lower mount back several
           inches, thereby lowering the rear end
          Reduce rear suspension travel to compensate for one rider instead of two


Tire
          Change the size of the rear tire
              o Current width is 150mm
              o Possible changes: 180mm, 190mm, 200mm, 210mm, 220mm
          Change the front tire to match the rear
              o Have a custom made front tire to match the rear
              o Buy a tire similar to the rear


Swing arm
          Custom build a swing arm to accommodate a wider rear tire
          Buy a swing arm to fit around a wider tire
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        Make a single arm swing arm (like Ducati)
        Take existing swing arm and clean up welds


Wheel design
        Three “claw” design
        Solid wheel design with appearance of spokes
        Cut image of a tiger into front and or rear wheel
        Manufactured in house (Brinkman Lab)


Brakes
        Remove existing calipers
        Custom fabricate calipers
        Purchase commercially available calipers


Drive
        Switch from a belt drive to a chain drive
             o If switching to chain, create adaptors to allow for change from belt to
                 chain
        Use a belt not as wide as the existing
        Extend the drive out to accommodate an increase in the rear tire width (to keep
         the drive in line)
        Modify swing arm in order to accommodate a kicked out drive
        Remove existing drive covers
             o Replace with commercially available chrome covers
             o Have existing covers powder coated
             o Replace with commercially available colored (black, orange, or other)
                 cover


Wheel Hubs
        Create wheel hubs to accommodate any changes in the drive (belt or chain)
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      Create custom hubs
      Purchase existing hubs


Headlight
      Create an original headlight design
             o Custom build metalworking
             o Custom build/buy glass
      Purchase a radical headlight
      Go without a headlight
      Reuse the stock light


Air Filter
      Remove existing
      Create a more polished version of existing
      Create a new cover design using the existing air filter
      Create a new cover using a different type/size/shape of air filter
      Display sponsor logos on air filter cover
             o Display sponsor logos by engraving onto chrome or other polished metal
             o Paint sponsor logos by painting onto air filter cover
             o Design cover into shape of a sponsors logo
      Go without an air filter cover for a naked look


Modify Raked Tree
      Increase rake angle by 5o to 10o (stock is 30.1o)
      Design and manufacture new triple trees
      Purchase new triple trees
      Replace stock triple trees with Mid-glide triple trees
      Replace stock triple trees with Wide-glide triple trees
      Purchase new, longer front forks
             o Purchase chrome forks
Project Number 05912                                                          Page 21 of 77


             o Purchase black forks
             o Purchase orange forks
             o Purchase forks to be painted black, orange, or other
             o Purchase inverted forks
             o Purchase standard forks


Exhaust
      Change to a left exiting exhaust
      Change exhaust to two into one
      Change exhaust to shortened straight pipes
      Change exhaust to street sweeper pipes
      Custom fabricated pipes
             o Fabricate pipes in house
             o Purchase custom fabricated pipes
      Purchase commercially available pipes


Seat
      Remove stock two-up seat
      Purchase or fabricate single seat
      Purchase or fabricate two-up seat
      Purchase or fabricate sissy bar
      Dimensions of new seat determined by the tank design
      Incorporate logo into the seat
             o 175th RIT anniversary
             o Sponsor logos


Electrical
      Fabricate rear lights into the rear fender (so as the light and housing are flush with
       the fender)
      Develop proximity sensors to placed on the bike
      Develop variable intensity lighting
Project Number 05912                                                       Page 22 of 77


      Create accent lighting for engine
      Create custom turn signals
      Replace keyed ignition with access code ignition
      Replace keyed ignition with toggle switch ignition


Conversion Kit
      Fabricate each component of the conversion kit and provide the completed kit to
       Santa Cruz Harley-Davidson at the conclusion of senior design two. This would
       require the team to fabricate or purchase three items of each design component,
       one for each of the two motorcycles, and one for the kit.
      Provide documentation recommending components that the kit would contain.
       Santa Cruz Harley-Davidson would be able to see the prototype kit in action; all
       modified design components would be fabricated or purchased and implemented
       on the customized motorcycles.
      Make the kit “bolt on” so that no welding or cutting was necessary throughout the
       customization process.
      Provide a kit that accommodates any and all changes that the team desires (this
       would include cutting and welding).


Concept Drawing
Based on the concepts developed by the team, the Industrial Designers developed
numerous concept drawings. Figure 1 is an example of one of the concept drawings.
Project Number 05912                               Page 23 of 77




                       Figure 1: Concept drawing
Project Number 05912                                                         Page 24 of 77


Feasibility Analysis


Introduction
The team performed a feasibility analysis on all of the concept development ideas. This
was done in order to identify the most desirable design option. Pros and cons of each
design were determined and reviewed in making decisions. A number of the design
alternatives were not feasible based on resource and time constraints put on this project;
these design options were not included within the pro and con evaluation.    Weighted
concept analysis and Pugh’s method were utilized in the decision making process for the
design components that proposed a difficult decision. Within these difficult decisions the
best option was not readily identifiable based on the pros and cons.


Gas Tank
       Replace with custom designed tank vs. commercially available tanks
            o Custom designed tank
                      Cons:
                              Team lacks expertise in metalworking (limiting in-house
                               capabilities)
                              Cost to outsource fabrication of in-house design: ~$2,000
                               per tank
                      Pros:
                              Radical, one of a kind design
                              Does not compromise the Industrial Designers’ design
            o Commercially available tank
                      Cons:
                              Compromises the Industrial Designers’ design
                              Not a radical design (is not as unique)
                      Pros:
                              Cost: ~$600 per tank
       Based on weighted concept evaluation, the commercially available tank is the
        best option based on the decision criteria. A Pugh’s Method analysis verified
Project Number 05912                                                         Page 25 of 77


        that purchasing a commercially available tank was the most feasible decision.
        The weighted concept evaluation and the Pugh’s method analysis can be found in
        Appendix C.


Handle Bars / Controls
       Remove current handle bars and controls and replace with custom built handle
        bars, built to conceal the bulkiness of the controls vs. purchase commercially
        available handle bars that conceal controls
           o Custom built handle bars
                      Cons:
                              No member of the team has experience designing handle
                               bars
                      Pros:
                              Conceal controls
                              Changes look of bike from a dirt bike to a chopper
           o Purchase handle bars
                      Cons:
                              Cost: ~$3000 per set
                      Pros:
                              Built by manufactures with experience
                              Conceal controls
                              Changes look of the bike from a dirt bike to a chopper
           o Suicide shifter
                      Cons:
                              Is not most practical deign for everyday riding bike
                              Is not as safe as standard shifting
                      Pros:
                              Radical design giving chopper edge to bike
       Purchasing commercially available handlebars is more feasible based on the
        teams’ lack of experience with building and designing handlebars. Suicide
        shifter is not feasible based on requirement to make the choppers everyday riders.
Project Number 05912                                                            Page 26 of 77



Ride Height
      Remove shocks to create a rigid vs. shorten shocks to lower ride height
          o Remove shocks
                     Cons:
                             Turns bike into a rigid, decreasing the ride ability of the
                              bike
                     Pros:
                             Gives bike a sleeker look by removing the shocks
          o Shorten shocks
                     Cons:
                             May result in possible problems with cornering clearance,
                              ground clearance and handling
                             Cost of new shocks $281 per set
                     Pros:
                             Gives the bike a squatter stance
                             As compared to the rigid, the bike is easier to ride
                              (comfort)
      In creating a bike that could possibly be ridden every day, it is more feasible to
       shorten the shocks then to make the bike into a rigid.


Tire
      Wheel Width
          o Width greater then 190mm
                     Cons:
                             Rear wheel widths in excess of 190mm will result in a
                              redesign of the XL (stock) swing arm; may make it
                              necessary to modify the drive in order to keep it in line.
                              Time involved to accomplish the redesign/ analysis/
                              fabrication of the swing arm and drive assembly may be
                              similar to other entire Senior Design projects.
Project Number 05912                                                         Page 27 of 77


                     Pros:
                             Will give bike the massive back wheel look of a chopper
          o Width equal to or less then 190mm
                     Cons:
                             Rear wheel may appear to be stock (stock XL width is
                              150mm)
                     Pros:
                             190mm is a proven good look on an XL according to Mike
                              James of Santa Cruz Harley-Davidson
                             No swing arm or drive redesign is needed
      Based on time constraints and expert opinion, it is more feasible to change the
       rear wheel to a width between 150mm and 190mm.
      Choosing between the two most commercially available combinations of rear
       wheel width and diameter available in the width range of 150mm to 190mm are
       190mm width on 17in diameter and 180mm width on 18in.
          o 190mm on 17in
                     Cons:
                             17 in diameter is smaller then other option with 18in
                              diameter
                     Pros:
                             Width is at apex of what will fit on standard Sportster
                              frame
                             Proven good look on Sportster according to Mike James of
                              Santa Cruz Harley-Davidson
          o 180mm on 18in
                     Cons:
                             180mm is not as wide as other option with 190mm width
                     Pros:
                             Diameter is the larger of the two options available
      It is more feasible to use a 190mm tire on the 17-inch wheel because the width of
       the tire is more important aesthetically then the wheel diameter. Also, Mike
Project Number 05912                                                           Page 28 of 77


       James, an expert in the field of Harley-Davidson customization, has
       recommended 190mm.


Swing Arm
Based on the analysis of the rear tire width, the 190mm tire will fit inside of the swing
arm. Therefore it is no longer necessary to redesign the swing arm. The single arm
swing arm has been eliminated from consideration based on two facts: it is a concept for
a sport bike, not a chopper; and the design and analysis involved in fabricating a single
arm swing arm are comparable to entire senior design projects in its scope and the
minimum time needed. For these reasons, the existing swing arm will be taken off and
cleaned up aesthetically (slight modifications).


Wheel Designs
      Wheels will be designed and fabricated internally, to take advantage of the
       Brinkman Lab and the team’s expertise in using the CNC machines. To ensure
       the design is sound, structural analysis will be performed.


Wheel hubs
      Purchase hubs vs. design and fabricate hubs
           o Purchase hubs
                      Cons:
                              Forces the team to design the wheel, and drive changes
                               around the hub
                              Does not utilize team’s expertise in using CNC machines
                      Pros:
                              Hub is professionally designed and fabricated
           o Design and fabricate hubs
                      Cons:
                              Hub is not be professionally designed and fabricated
                      Pros:
Project Number 05912                                                             Page 29 of 77


                               Allows team to design the hub around the other
                                components of the bike
                               Utilizes the team’s expertise in using CNC machines
        It is more feasible for the team to design the hubs around the other components of
         the bike, vs. designing the other components of the bike around the hubs. For this
         reason, the team will design and fabricate the hubs in-house.


Brakes
        Custom design and fabricate calipers vs. purchasing commercially available
         calipers
             o Custom calipers
                       Cons:
                               Calipers are not professionally designed and fabricated
                       Pros:
                               Utilizes team’s skills and resources available
                               Gives a potential location for incorporating sponsor logos
                                to bikes
                Commercially available
                       Cons:
                               Does not utilize team’s skills or resources available to team
                       Pros:
                               Calipers are professionally designed and fabricated
        Based on the team’s experience with designing and fabricating calipers, it is more
         feasible to custom design and fabricate calipers.


Drive
            Modify drive to a chain vs. modify drive to a narrower belt
             o Chain
                           Cons:
                                   Forces team to redesign parts of the dive in order to
                                    accommodate change from belt to chain
Project Number 05912                                                            Page 30 of 77


                                  Increased maintenance is required (when compared to a
                                   belt drive)
                          Pros:
                                  Decreases the amount of space needed for drive as the
                                   chain is narrower then the belt
            o Belt
                          Cons:
                                  Does not open up as much space as the chain belt does
                                  Is not as reliable as wider belt or chain
                                  Would require swing are redesign
                          Pros:
                                  Does not require as much redesign as the chain drive
                                   does
           Based on the Pugh’s Method analysis performed, the chain drive is the most
            feasible option. The Pugh’s Method analysis is Figure C-5 located in
            Appendix C.


Headlight
      Custom fabricate
            o It is not feasible to create a custom in-house headlight as the team as no
               experience with designing lights or with glass.
      No headlight
            o It is not feasible to go without a headlight due to safety issues addressed in
               the analysis and synthesis section of this paper.
      Standard headlight
            o It is not feasible to use the standard headlight, as it does not fit the
               appearance of the new bike.
      Radical headlight
            o It is most feasible to purchase a radical headlight based on the elimination
               of the previous three ideas. The headlight will be chosen by the Industrial
Project Number 05912                                                             Page 31 of 77


                 Design students in order to have the headlight fit aesthetically with the rest
                 of the bike.


Air filter
       No filter cover
             o It is not feasible to go without an air filter cover, as this is a prime location
                 for sponsor logo placement.
       Filter cover
             o It is more feasible to remove the cover and replace with a newly designed
                 cover, than to remove the cover and the filter and start all over. Without
                 changing the filter type or size, there will not be any concerns over
                 compatibility.


Modify Raked Tree
       Increase rake angle by 5o, 7o, or 10o
             o Based on recommendation of Sportster customization expert Bob Davis,
                 7o was chosen as angle of possible increase
                         Cons: (of increasing angle)
                                 Potential for stiction
                                 High speed steering reduction due to increased trail
                         Pros:
                                 Proven good look, good ride by Bob Davis of Santa Cruz
                                  Harley-Davidson
                                 Gives bike chopper look
                                 Part of requirement is to increase rake angle by some
                                  amount
       Based on the recommendation of Bob Davis, the team chose 7o as the possible
        increase to the rake angle. As increasing the rake angle was a basic requirement
        in making the Sportster into a chopper, 7o is the most feasible increase to the rake
        angle.
       Purchase new triple trees vs. fabricating new triple trees
Project Number 05912                                                        Page 32 of 77


          o Purchase new triple trees
                      Cons:
                              Purchased triple trees cost ~ $225
                              Does not utilize team’s expertise in using CNC machines in
                               the Brinkman Lab
                      Pros:
                              Professionally manufactured
          o Design and fabricate custom triple trees
                      Cons:
                              Team has no experience with designing triple trees
                      Pros:
                              Will utilize teams expertise in using CNC machines in the
                               Brinkman Lab
                              Team has experience designing and fabricating similar
                               parts
                              Only cost incurred is for blanks
      Based on the team’s expertise in using the CNC machines in the Brinkman Lab,
       and the cost savings in purchasing blanks over finished products, it is more
       feasible to design and fabricate custom triple trees in house.
      Mid-glide front-end vs. Wide-glide front-end
          o Both front-end arrangements give the bike a wider stance from the front.
              However, the Wide-glide might appear too wide on the smaller Sportster.
              It for this reason the Mid-glide front-end is more feasible then the Wide-
              glide.
      Based on the requirement to increase the fork angle, new longer forks will need to
       be purchased to accommodate this change.
      The decision to choose inverted forks vs. standard forks, and the color of those
       forks has nothing to do with performance and everything to do with style and
       looks. For this reason, the Industrial Design students have been tasked with
       choosing the fork style and color. They have decided inverted forks will be
Project Number 05912                                                          Page 33 of 77


       purchased for the bike; one bike will have chrome forks while the other will have
       black.


Exhaust
      Remove current exhaust and replace with custom pipes on right hand side vs.
       custom pipes on left hand side
          o Right hand exhaust
                     Cons:
                             Looks like the majority of bikes on the market (both stock
                              and custom) as right hand exhaust is standard
                     Pros:
                             Sportster 883C is built with and for right hand exhaust
                             Proper flow of exhaust can easily be maintained
                          
          o Left hand exhaust
                     Cons:
                             Proper flow of exhaust may be difficult to obtain on
                              Sportster
                             Sportster 883C is not built for left hand exhaust, leading to
                              possible issues with space constraints
                     Pros:
                             Left hand exhaust is not the norm, thereby helping to create
                              a custom look
                             Will give the exhaust a radical look
      Based on the difficulty with redesigning the exhaust pipes to accommodate a left
       side exhaust, it is more feasible to make the exhaust on the right side of the bike.


Seat
      New two up seat
Project Number 05912                                                           Page 34 of 77


             o It is not feasible to use a two up seat because the new fiberglass fender
                will not be able to support a weight of a rider the way the current sheet
                metal fender does.
      Sissy bars
             o Although sissy bars are common on choppers, they do not fit aesthetically
                with the design concept for the bike.
      Single seat
             o Based on the elimination of the two up seat, the single seat is the most
                feasible. The single rider seat will be purchased and then modified to both
                fit the bike and to showcase sponsor logos.


Electrical
       With the Sportster 883C’s participation in a parade, efforts were made on the
electrical system aspect of the bike to make it stand out. Special lighting effects were the
first to be considered in order to receive high visibility when the bike is in motion.
Another key issue addressed was the safety of the rider. As mentioned, many traffic
fatalities involving motorcycles are due to the low visibility of motorcyclists. So keeping
safety and visibility in mind, several concept systems were developed. Two systems
stood out as feasible, and were researched for the duration of the quarter.
       The first concept system was a safety feature for the stock 883C Sportster which
would implement LED and RF technology. Using motion/proximity sensor technology, a
proximity sensor system will ensure that all automobiles within a determined perimeter
around the bike are alerted to the bike’s presence. The bike would be fitted with LEDs
that would illuminate when an automobile is detected by the onboard sensors. The
sensors would communicate with a main control unit, which would illuminate the LED’s
via a LED driver. A search for appropriate proximity sensors yielded three distinct types:
Infrared, Capacitive, and Inductive. Searching for sensors of the capacitive and inductive
type yielded disappointing results. The maximum range of theses types of sensors was
on the order of millimeters, an unacceptable range. A new search pertaining to infrared
sensors found a larger sensing range, but required a clean surface for reflection. The
remaining option in implementing this system was to purchase an existing system that
Project Number 05912                                                         Page 35 of 77


utilized sensors with adequate range. This led to the discovery of RSE Developments
Parktronic Radar system. This system is a product of RSE Developments and is used in
Mercedes-Benz automobiles. The system detects objects to the rear of a vehicle up to a
meter away. This system would be costly and would need to be modified to fit the
motorcycle. Modification of the system would be difficult without manufacturer
information, and could possibly violate proprietary rights. Seeking advice from
professors in the RF field, the collective agreement was that the system would take some
time to implement. Given a deadline of April 30th, a set budget, and limited human
resources, the system was determined to be not feasible.
       The second concept system also embodies the two goals of safety and high
visibility. The Accent Lighting System was envisioned to provide an artistic lighting
appeal while alerting nearby motorists to the bike’s presence. This lighting system would
flash or grow in intensity based on the RPM of the motorcycle motor. The system would
be powered by the bike’s 12V battery. The system would have to be power efficient, thus
LEDs were determined to be the source of lighting.


Conversion Kit
      Fabricate each part three time vs. develop documentation to support custom
       customization
           o Fabricate each part three times
                      Cons:
                              Producing each part three times increases the cost of the
                               project by approximately 30%
                              Parts to be used on Tiger Chopper are extremely custom
                               and specific to this bike/project
                              Two models (Tiger Chopper and Tiger Chopper replica)
                               will already exist
                      Pros:
                              Santa Cruz Harley-Davidson will have physical
                               representation of what kit would contain
           o Develop documentation
Project Number 05912                                                           Page 36 of 77


                     Cons:
                             Santa Cruz Harley-Davidson will not have a physical
                              representation of what kit would contain
                     Pros:
                             Cost effective: team will not waste limited budget on parts
                              not needed to complete the two bikes
                             Will be more flexible: team can suggest items similar to
                              what was used in projects bikes, that may not be exactly the
                              same
                                  o The Tiger Chopper will be highly customized to
                                      meet the needs of RIT, Kate Gleason College of
                                      Engineering and our team’s requirements for Senior
                                      Design. These needs most likely are not the same
                                      for the potential consumer of the conversion kit.
                             Resource effective: team will not waste valuable time and
                              machine time by producing a third set of parts
      Based on the team’s budget, constraints on time and machining resources, it is
       more feasible to develop documentation for the conversion kit then it is to
       produce three sets of parts.
Project Number 05912                                                           Page 37 of 77


Specifications

Introduction
This section outlines the design objectives and determines the performance and design
specifications the project must meet.


Design Objectives
The overall goals of the final project design make up the design objectives.
      Convert a stock 883C Harley-Davidson Sportster motorcycle into a custom
       chopper motorcycle. This conversion must be completed without modifying the
       frame. The conversion component parts must be manufactured so that a typical
       motorcycle mechanic could assemble the custom motorcycle.
      Documentation of all the customization changes must be accounted for and
       compiled. This documentation will represent a customization kit that could be
       assembled, marketed and sold by Harley-Davidson, or motorcycle parts
       distributors.
      The custom designed motorcycle that the senior design team creates must be
       operable.


Design Specifications
Design specifications dictate the functionality of the final design. The specifications
were determined from the feasibility analysis.


Gas Tank
      Replace stock gas tank with a smaller more astatically pleasing commercially
       available gas tank. The commercially available tank will be selected to match the
       design drawings of the finished motorcycles gas tank provided by our teams’
       industrial designers.
Project Number 05912                                                         Page 38 of 77


Handlebars / Controls
      Replace existing handlebars / controls with a more astatically pleasing
       commercially available set of handlebars / controls. The commercially available
       handlebars / controls will be selected to match the design drawings provided by
       our teams industrial designers.


Ride Height
      Replace existing rear shocks (12 inch eye to eye), with a commercially available
       (11 inch eye to eye) astatically pleasing set of rear shocks. This change aids in
       lowering ride height of the finished motorcycle approximately one inch.


Tires and Wheels
      The team will replace the stock 150 mm rear tire with a commercially available
       190 mm rear tire.
      The team will replace the stock 90 mm front tire with a more astatically pleasing
       commercially available 90 mm front tire that matches the rear tire design.
      The team will purchase a commercially available rear wheel blank that will fit the
       190 mm rear tire. The team decided to order a 17-inch diameter, 190 mm rear
       wheel blank.
      The team will purchase a commercially available front wheel blank (21-inch
       diameter, 90 mm).


Swing Arm
      The team will remove and slightly modify the existing stock swing arm on each
       motorcycle. The swing arm from each motorcycle will be cleaned up (weld
       marks minimized) and repainted to match the frame design.


Wheel design
      Wheels will be designed and fabricated internally, to take advantage of the
       Brinkman Lab and the teams expertise in using the CNC machines. The design of
Project Number 05912                                                           Page 39 of 77


        the front and rear wheel is displayed in the analysis and synthesis section of this
        paper. To ensure the design is sound, structural analysis will be performed.


Wheel Hubs
       The team will design and fabricate the wheel hubs to fit the wheel designs. The
        team will purchase stock aluminum and machine the designed hubs in the
        Brinkman Lab.


Drive
       Team decided to replace the existing Kevlar belt drive with a chain drive. The
        team will calculate a new drive ratio in implementing the chain drive.


Headlight
       Replace existing headlight with a more astatically pleasing commercially
        available headlight. The commercially available headlight will be selected to
        match the design drawings provided by our teams’ industrial designers.


Air Filter
       The team will design and fabricate a custom air filter cover to replace the stock
        cover. The custom air filter cover will be machined in the Brinkman Lab to
        match the design drawings of the industrial designers.


Modify Raked Tree
       Team chose to increase the rake angle by seven degrees. This would be
        accomplished in the design and fabrication of the triple clamps.
       The stock front forks are going to be replaced with an alternate set of
        commercially available front forks. The commercially available front forks that
        are going to be purchased will match the design objectives set forth by the
        industrial designers. The new front forks need to be longer than the stock front
        forks to compensate for the increased rake angel. These calculations are
        displayed within the analysis and synthesis portion of this paper.
Project Number 05912                                                        Page 40 of 77



Exhaust
      The stock exhaust pipes will be replaced with custom designed exhaust pipes that
       represent the design set in place by the industrial designers.


Seat
      The stock two up seat will be replaced with an alternate commercially available
       single seat.
      The senior design team will create a single seat pan in order to implement a single
       seat design. The single seat pan will be a modified version of a commercially
       available seat pan.


Electrical
      The senior design team will concentrate our efforts in the electrical department to
       the development of a LED lighting system. This system will be variable based on
       the RPM of the bike, thereby giving the motorcyclist more visibility at higher
       (more dangerous) speeds. This lighting will also be used to accent the engine.


Conversion Kit
      Each portion of the motorcycle customization will be documented. This
       documentation will make up a paper version of the customization kit.
Project Number 05912                                                              Page 41 of 77


Analysis and synthesis


Introduction
This section reviews the analysis used to determine the specifications of the project.


Increased Lighting
       Approximately 4.9 million motorcycles were registered in the United States in
2001. While these represent only 2% of all registered vehicles, motorcycles account for
7% to 12% of all motor vehicle-related fatalities. Per mile traveled, motorcyclists are 16
times more likely than passenger car occupants to die in a traffic crash and four times as
likely to be injured. While only 20% of car crashes result in injury or death, that number
increases to 80% for motorcycle crashes.
       A study put together by Harry Hurt of the University of Southern California
investigated the causes and effects of motorcycle accidents. Hurt investigated almost
every aspect of 900 motorcycle accidents in the Los Angeles area. Additionally, Hurt
and his staff analyzed 3,600 motorcycle traffic accident reports in the same geographic
area. Hurt and his staff were able to identify a number of interesting findings that aided
in our teams motorcycle design.
       Hurt found that approximately three-fourths of the motorcycle accidents he
studied involved collision with another vehicle, which was most usually a passenger
automobile. During two-thirds of these accidents (involving collision with another
vehicle) the driver of the other vehicle violated the motorcycle right-of-way and caused
the accident. The failure of motorists to detect and recognize motorcycles in traffic was
the predominating cause of motorcycle accidents. The driver of the other vehicle
involved in the collision with the motorcycle did not see the motorcycle before the
collision, or did not see the motorcycle until too late to avoid the collision.
       After reading Harry Hurt’s reports on motorcycle accidents, our senior design
team realized that efforts needed to be taken in order to improve motorcycle conspicuity.
The team proposed the implementation of a LED lighting system. The LED lights would
add to visual detection of the motorcycle. A study published in the Journal of Safety
Research, by Freedman and Davit reported on the aspects of adding lights to the sides
Project Number 05912                                                        Page 42 of 77


and rear of motorcycles and mopeds. The study found that the adding lights to the
motorcycles rear and sides improved conspicuity. Adding the lights and improving the
conspicuity of motorcycles and mopeds would hopefully reduce the number of
motorcycle accidents caused by failure to detect a motorcycle in traffic.


Handlebar Design
       Based on studies of motorcycle use, one of the primary complaints of riders is
muscle fatigue in the upper arm and shoulder. One of the goals of this project was to
provide the end user with a chopper style motorcycle that is capable of being an
“everyday rider.” Therefore, biomechanics were utilized in the design of the handlebars
for the motorcycles in order to reduce the moment at the shoulder.
       The ideal handlebar design would consist of the smallest moment at the shoulder
while maintaining full functionality. The smallest moment at the shoulder would consist
of the arm positioned straight down. However this position is not functional to control
the motorcycle. On the other extreme, the moment would be the largest with the upper
arm and forearm fully extended in front of the rider. Therefore the optimal design was
somewhere in between these positions. The project team experimented with various arm
angles to determine the smallest moment while still maintaining full arm motion required
to use the handlebars safely. This position was found to be 45 degree angle at the
shoulder-upper arm, and the forearm be fully extended (Figure 2).
Project Number 05912                                                         Page 43 of 77




                                              45 degrees




                      Figure 2: Optimal arm position during riding


       After the arm position was developed, the physical measurements of the end users
needed to be calculated. The ANSUR military database was used to determine the
forearm, upper arm, and sitting torso lengths for the end user. No user data was available
for the H-D Sportster 883C, however it has been given a reputation as a motorcycle for
both genders. Harley Davidson produces a Sportster 883L which is smaller and more
applicable for smaller females. A range was used to determine the physical
measurements of the Sportster 883C end user. The smallest rider was determined to be
the 40th percentile female based on leg length and ride height constraints. The largest
rider was calculated to be 70th percentile male based on leg length and the distance
between the seat and foot controls. The range provided a rough estimate of the end users
assuming smaller females would use the 883L, and larger males would use a larger style
motorcycle. Based on these measurements and the optimal arm position, it was
determine that the handlebars needed have a 27 inch horizontal distance from the back of
the seat to accommodate the 40th percentile female. (See appendix for calculations).
Project Number 05912                                                                      Page 44 of 77


This measurement allows for the reduction of the shoulder moment for the average end
user.
Electronics
Specifications of feasible system:
The accent lighting (LEDs) will illuminate the bike’s motor components. The LEDs will
blink at four discrete frequencies throughout the 5600RPM spectrum. The rider will have
control over the LEDs through an on/off switch, and a selector that will allow him to
choose two different modes of operation.


In the first mode, the LEDs will appear to be constantly on. The second mode of
operation will result in the LEDs blinking at a frequency proportional to the RPM of the
motor. An outline of the blink frequencies is shown in Table1.

                      RPM       Blink Frequency
                      0-1500    Constant On Note: The bike is in Neutral/Park/Motor Off
                      1500-2000 10Hz
                      2000-3000 20Hz
                      3000-4000 30Hz
                      4000-5600 40Hz
                                 Table1: Blink Frequency Table.

The control of the modes of operation will be a responsibility of the control unit. This
control unit will be powered by the motorcycle’s 12V battery and will be an analog
circuit, or a digital controller.


Possible General System Designs:
The initial system design yielded two possible options in powering the LEDs with the
implementation of a digital controller. The third design shows the controller being an
analog circuit. The LEDs will be powered by an LED driver that is connected to the
battery as shown in Figure 3. This LED driver will be controlled by the digital controller.
This system is attractive due to multiple ways of implementing the LED driver.
Project Number 05912                                                          Page 45 of 77



                                    User Interface



                                                                         12VDC
                                        Digital
            RPM signal                                                   Battery
                                        Control
                                         Unit


                                  LED Driver



                               Accent Lighting( LEDs)


                     Figure 3: Digital Controller- Relay driven system

The second design would eliminate the LED driver, and allow the digital controller to
drive the LEDs directly. This system is shown in Figure 4. This system was found to be
impractical due to the operating output voltage of researched digital controllers being less
than 12V.

                                    User Interface



                                                                         12VDC
                                       Digital
          RPM Signal                                                     Battery
                                      Controller



                               Accent Lighting (LEDs)

                   Figure 4: Digital Controller powering LEDs directly

The third system design shows the LEDs being powered by an analog circuit that will
read the RPM signal and condition it to provide ~12V to the accent lighting. This system
is outlined in Figure 5.
Project Number 05912                                                              Page 46 of 77



                                       User Interface



          RPM Signal                                                        12VDC
                                          Analog
                                                                            Battery
                                          Circuit



                                     Accent Lighting

      Figure 5: Analog control circuit conditioning RPM signal and powering LEDs

The LEDs were chosen by the industrial designers in order to be coherent with their
vision of the bike. These lights were purchased from Kuryakyn. The LEDs were tested
and were found to handle 14V and drew .41A safely. This voltage is well above the
battery voltage, which will be powering the LEDs. This test was important to make sure
the lights will handle a voltage that may increase above 12V.

Pugh’s method is shown in Table 2 comparing the three systems.

 GENERAL SYSTEM
 COMPARISON                   Digital Controller-LED Driver Digital Controller Analog Circuit
 Design Complexity                                         3                  3             2
 Sufficient Equipment                                      5                  5             5
 Cost of Total Materials                                   3                  4             2
 Availability of Components                                5                  5             5
 Versatility of Design                                     5                  3             1
 Power Efficiency                                          5                  4             3
 Mean Score                                     4.333333333                   4             3
 Normalized Score                                       1.00              0.92           0.69
                 Table 2: Pugh’s Method evaluation of possible systems.

Using Pugh’s method, it was determined that the system implemented will be a digital
controller-LED driver pair. This system has an edge over the lone digital controller and
analog controller circuit systems due to its versatility. The digital controller can be
reprogrammed to perform different functions, thus making it very versatile.
Reprogramming a digital controller has a faster turn around rate than redesigning a
hardwired analog circuit. The robustness of this system will make future customization
of the system more time efficient.
Project Number 05912                                                          Page 47 of 77



The RPM signal proved to be a difficult part of the design. There were several sources
from which this signal could be read by the digital controller. The sources that provided
an alternating signal or voltage that varied proportionally to increasing RPM are the
alternator, voltage regulator, ignition control module, and crank position sensor (CKP).
The initial design would read the voltage changes coming from the voltage regulator.
The downside of this would be the need for additional circuitry to limit the amount of
voltage the digital controller experiences. This regulated voltage would not have a
frequency associated with it, thus a variation in RPM would not be detected. The next
source considered was the tachometer DATALINK signal. The waveform of this signal
was not mentioned in the service manuals, so the best estimation was that it being a
square wave that varied in duty cycle or frequency. Initial tests with the oscilloscope
connected to the line yielded a signal that peaked at ~8V. The origin of the signal was
traced to the Ignition Control Module (ICM). The ICM received and processed the signal
from the crank position sensor. Contact was made with technical support at Harley-
Davidson, which resulted in learning that the information on the DATALINK signal was
proprietary. The final decision was to use the signal that comes directly out of the crank
position sensor. This signal is not modified by any hardware and process that is deemed
proprietary. The next process was to choose a sufficient digital controller that could
sample such a signal that varied in frequency.




CKP TEST:
The crank position sensor on the Sportster was tapped and the signal measured. This
signal is assumed to alternate in frequency directly with motor rotation. The voltage
level of this signal was a major concern due to the sensitivity of the digital controller and
its voltage limits. The signal was measured to be ~27V at idle which is about 1000RPM
(+/- 50). The bike was then revved to approximately 75% of redline (5600 RPM). This is
an approximation due to the lack of a tachometer on the bike. The voltage level of the
signal at 75% was found to be ~45V (4200RPM). Due to the lack of information on the
Project Number 05912                                                          Page 48 of 77


hardware and its specifications (proprietary information of Harley-Davidson Motor
Company), a linear approximation of voltage levels was made as a function of RPM.

                               RPM          Voltage of Signal
                                     1000          27V
                                     2066          33V
                                     3126          39V
                                     4186          45V
                                     5252          51V
                    Table 3: Approximate voltage level of RPM signal

After performing the CKP test, a new addition to the general system design was realized.
The problem with the CKP signal is that the voltage level fluctuates from 27V at idle to
over 45V near redline. The majority of digital controllers can only read signals less than
5V. A circuit will have to be designed to limit the voltage that the digital controller is
exposed to, thus the design in Figure 6. A simple voltage divider will be able to divide
the incoming voltage level of the signal. The calculations for the resistor values of the
voltage divider are shown in Calculations 1.

Calculations 1:
The RPM signal voltage is reduced to 6.25% of it original value through voltage division.
                                      2.2k
                              k                  .0625
                                  2.2k  33k


After the signal is voltage divided, it has to be read by the digital controller at less than
5V. The answer to further regulating the voltage was to implement a MOSFET transistor
at the output of the voltage divider.       This MOSFET will constantly operate in the
saturation region with each positive going transition being conveyed to the digital
controller. By counting the number of positive transitions that occur in a second, a
frequency is calculated by the digital controller. This frequency would then be modified
by a scalar. This scalar would determine the frequency at which the LEDs blink. A
MOSFET does not conduct current through the gate terminal, and theoretically has an
infinite resistance between drain and source terminals. These characteristics allow the
voltage division stage to operate ideally. These characteristics also allow the MOSFET
to isolate the voltage divider and any harmful current spikes. The two series resistors
attached to the source terminal of the MOSFET will drop the voltage of the input to the
Project Number 05912                                                            Page 49 of 77


digital controller. The first resistor determines the upper voltage limit that the digital
controller will sample. The second resistor will determine the lower limit of the input
and prevent a shorting of the signal to ground.
A maximum of 3.08V will be generated as digital controller input when the bike reaches
the approximated RPM redline. A voltage level of 1.308V will be sent to the digital
controller when the motor is at idle. The general design is shown in Figure 6. The
voltages at key RPM values were estimated from the CKP test (Table 3).                 It was
determined from iterative PSPICE simulations that for the MOSFET to receive gate
voltages within its scope, the RPM signal voltages will be reduced to 6.25% of their
value. The circuit was simulated in PSPICE to ensure proper operation of the regulator
within the voltage range of the signal from idle (1000RPM) to redline (5600RPM). The
results of this simulation are shown in Figure 7 and Figure 8.



                    V1
       From CKP                 R4                M1
                                                                   0
                               33k
                                              MbreakN
                                                V
                    FREQ = 16hz               R5
                    VAMPL = 27V               12k
               0    VOFF = 0v                               R6V
                                                            2k
                                                                       To Digital Controller
                                          0
                                                              V

                                                            R3
                                                            8.2k


                                                        0
Figure 6: Voltage regulator circuit
Project Number 05912                                                                                                 Page 50 of 77

  6.0V




  5.0V                                                                                                   (77.185m,5.7241)




  4.0V
                                                       Input voltage level at 27V (Idle)




  3.0V



                                                                                                         (77.185m,1.6735)

  2.0V                          (16.560m,1.3455)




  1.0V




       0V




 -1.0V
            0s             10ms          20ms        30ms       40ms       50ms        60ms       70ms        80ms          90ms   100ms
                 V(R6:1)      V(M1:d)     V(R6:2)
                                                                           Time

                   Figure 7: PSPICE simulation results of voltage regulator at IDLE RPM
 15V




                                                       (34.783m,10.116)

                                                                          Input voltage at approximated redline(5600RPM)
 10V




                                          (24.144m,3.9187)
  5V
        3.0320m,3.0821)




  0V




 -5V
       0s             10ms              20ms        30ms       40ms        50ms       60ms        70ms        80ms          90ms   100ms
            V(R6:1)     V(M1:d)          V(R6:2)
                                                                           Time

   Figure 8: PSPICE simulation results of voltage regulator at estimated redline RPM
Project Number 05912                                                         Page 51 of 77


Digital controller Algorithm:
The algorithm to control the overall lighting process will involve acquisition of the RPM
signal, processing of that signal, and relaying the signal to the LED driver. The algorithm
will also iteratively check the state of the on/off switch and the mode selection switch.
The digital controller algorithm will be programmed in C language and compiled into
assembly language. The flow chart of the algorithm is shown in Figure 9.


                                        Check Status of Mode
                                               Switch



             Mode1:                        Mode1?              LEDs
             Sample RPM                                        Constant On
             frequency



                If RPM
                 <2000




                If RPM                     LEDs Flash
                 <3000                     at 10Hz




                If RPM                     LEDs Flash
                 <4000                     at 20Hz




                If RPM                     LEDs Flash
                 <5000                     at 30Hz




                  Else                     LEDs Flash
                                           at 40Hz



                    Figure 9: Flowchart of digital controller algorithm
Project Number 05912                                                                   Page 52 of 77


Pseudo code for the algorithm is shown in Figure 10.


 //Accent Lighting System control

 //Interrupts:
 Check state of mode selection switch
 IF status = modeOne

         //Processing of RPM signal:
         For Loop (Read signal for 1 second) // Count number of on’s that occur in a second
         if( input > Threshold of positive transition )
                   counter++;                    // Count the number of positive transitions
         end

         counter = freq;

         // Divide counter to output corresponding frequency in accordance with frequency
 table
         If( counter < 2000 RPM)
                  Output lights constant on.
         If( counter < 3000 RPM)
                  Output to lights at frequency 10Hz
                  //Divide the RPM signal frequency so LED blinking is visible
                  output = freq* ProportionalConstant;
         If( counter < 4000 RPM)
                  Output to lights at frequency 20Hz
                  output = freq* ProportionalConstant;
         If( counter < 5000 RPM)
                  Output to lights at frequency 30Hz
                  output = freq* ProportionalConstant;
         Else
                  Output to lights at frequency 40Hz
                  output = freq* ProportionalConstant;

 ELSE

 Send to LED controller 5V Constant on mode

                           Figure 10: Pseudo code for digital controller


Materials:
User Interface:
Keeping a budget in mind, the interface to control the lighting was kept simple to C&K
TP Series Tiny Pushbutton Switches. The alternative to push button switches was an
LCD touch screen interface. This could not be implemented in the time scale of this
project due the amount of electronics experience on the team.
Project Number 05912                                                         Page 53 of 77

USER INTERFACE COMPARISON Pushbutton Switches         LCD Touch Screen
Design Complexity(Implementation                    3                 2
Sufficient Equipment                                3                 3
Cost of Total Materials                             4                 1
Availability of Components                          4                 3
Versatility of Design                               3                 5
Power Efficiency                                    3                 1
Mean Score                               3.333333333                2.5
Normalized Score                                 1.00              0.75
                  Table 4: Pugh’s Method evaluation of user interfaces


Digital Controller:
The digital control unit sought after must allow for input/output ports for the user
interface mode selection, on/off switch, RPM signal, and output to drive the LED driver.
Research of an appropriate controller led to the following comparison shown in Table 5.

The controllers considered were:
DIGITAL CONTROLLER
COMPARISON                           PIC-12F629             Z8F011AHH020EC         CY8C22113-24PI
Manufacturer                          Microchip                   Zilog               Cypress
Memory Size (FLASH)             1024Kx14 words FLASH               1K                    2K
RAM                                    64bytes                  256bytes              256bytes
EEPROM                                128bytes
NVDS                                                             16bytes
VDD                                      6.5V
Operating Voltage                      2V - 5.5V                  2.7-3.6
I/O Lines                                  6                        17                      6
UART                                                                 1
Serial Lines                              yes                       no
A/D                                        4                         3
CLK Speed                               20MHz                     20MHz                   24MHz
Power Dissipation                       800mW
Price                                    1.68                      3.18                   2.50
                        Table 5: Comparison of digital controllers.

This circuit will have a high degree of flexibility with the implementation of a micro-
controller as compared to an analog circuit. The frequencies at which the LEDs blink can
be changed with modification to the controller’s code.


LED Drivers:
The search for an appropriate LED driver resulted in the following devices shown in
Table 6. The final decision was to implement an NMOS transistor device due to several
Project Number 05912                                                                     Page 54 of 77


distinct advantages over the other devices. The NMOS transistor is a stable device that
can easily control currents with changes at the gate voltage. This device is also more cost
effective than other researched items, and is readily available. The device also has a high
switching frequency, which is more than sufficient for the application. The driver will
receive a controlling signal with a calculated frequency from the digital controller.



LED DRIVER COMPARISON        LED22V1A2DW                 LM2623                 CT2100-400            ALD1103PB
                                                         Gerneral Purpose Boost Quad Solid
Device                       LED Controller              Converter              State Relay           MOSFET
                                                                                                      Advanced
                                                                                                      Linear
Manufacturer                 Analog Technologies Inc.    National Semiconductor     Aeroflex          Devices
Design Complexity                                    3                          3                 2             5
Sufficient Equipment                                 3                          3                 3             3
Cost of Total Materials                              3                          4                 2             5
Availability of Components                           3                          3                 3             5
Versatility of Design                                4                          4                 4             3
Power Efficiency                                     5                          4                 3             3
Mean Score                                        3.50                       3.50              2.83          4.00
Normalized Score                                  0.88                       0.88              0.71          1.00
                       Table 6: Pugh’s Method evaluation of LED drivers

Comparing viable LED driver devices, it is apparent that a MOSFET would be the most
cost effective and easy to implement. The team has the most experience with an NMOS
device from previous drive applications, thus its high rating on design complexity.
Researching several NMOS integrated circuit chips led to the following comparison of
the most feasible shown in Table 7.



   MOSFET DRIVER COMPARISON
   Device                               2SK2549                          MMBF170
   Manufacturer                         TOSHIBA                          Diodes Incorporated
   Drain Current Rating                 2A                               800mA
   VDS Rating                           16V                              60V
   Threshold Voltage                    1.1V                             3V (max)
   Cost                                                           0.78                                0.1
                      Table 7: Pugh’s Method evaluation of LED drivers

The LED driver will be the MMBF170 by Diodes Incorporated due to its high voltage
rating, and satisfactory drain current. This component is also cheap compared to the
Toshiba MOSFET.
Project Number 05912                                                         Page 55 of 77



Voltage Regulator:
The problem with the CKP signal is that the voltage level fluctuates from 27V at idle to
over 45V near redline. The ALD1103PB was the MOSFET chosen to regulate input
voltage to the digital controller due to its ease of implementation and the ability to model
it in the PSPICE software environment. Another reason this device was chosen is due to
the team’s previous experience through lab implementation. The voltage regulator at the
input of the Ald1103PB divides the voltage as explained in the CKP test section.


The resistors chosen for the voltage divider stage and the voltage regulator stage are of
the values shown in Figure 6.      These resistors are rated at 1/4W. The calculations
determining the power rating are shown in Calculations 2.

Calculations 2:

Resistor 1 Power Rating Calculation:

                              V 1  27V  1.345V  25 .655V
                              V 2 25 .655 2
                                            .019 W
                               R   33 k

Resistor 2 Power Rating Calculation:

                                V 1  5.621V  0  5.621V
                                V 2 5.621 2
                                            .002 W
                                 R 12 kk


Resistor 3 Power Rating Calculation:

                              V 1  1.627 V  1.308V  .319 V
                              V 2 .319 2
                                         50 W
                               R   2k

Resistor 4 Power Rating Calculation:
Project Number 05912                                                             Page 56 of 77

                                   V 1  1.308V  0  1.308V
                                   V 2 1.308 2
                                               208 W
                                    R   8.2k




Triple Clamp Design
For the top triple clamp, all of the constraining is done at the seven-degree hole in the
rear. It is this hole that the steering shaft ties the triple clamps to the frame. Therefore,
the constraint that effects the surface on the inside of the rear seven-degree hole is no
translation of, or rotation about, the x or z directions. The translation in the y direction is
constrained by the top surface around the rear seven-degree hole. It is on this surface that
a bolt will be seated which pulls the assembly together, thus constraining translation in
the y direction. There are also constraints on the surfaces inside the bolt holes that will
be used to provide clamping force. In the top triple clamp there are eight holes that will
have bolts going through them to provide this clamping force. The rigid connection
constraint was used on the inside surface of each of the clamping bolt holes. This models
the part as if there are bolts in the holes as there will be in the real part.


The loading is based on a worst-case scenario of a head on collision. The force applied to
the top triple clamp in this scenario is in the positive z direction acting on the front
surface of the fork tube holes. The direction is based on the moment created about the
lower triple clamp. The force that is applied for this scenario is 5969 lb acting at each of
the fork tube locations. There is also the need to address the vertical force acting on the
top triple clamp. The vertical force is acting in the positive y direction and assumes a no
slip condition between the triple clamps and the fork tubes. The force is derived also
from the worst-case scenario. This resulted in a force of 979 lb acting as a surface force
in the positive y direction on each of the fork tube holes.
Project Number 05912                                                              Page 57 of 77


Figure 11 is the constraint and loading schematic for the top triple clamp. The constraints
and loading positions are chosen on the basis of creating a model that most effectively
resembles how the forces will actually apply to the part.




             Figure 11: Constraint and Loading Schematic- Top Triple Clamp

        For the lower triple clamp, all of the constraining is done at the seven-degree hole
in the rear. It is this hole that the steering shaft ties the triple clamps to the frame.
Therefore, the constraint that effects the surface on the inside of the rear seven-degree
hole is no translation of, or rotation about, the x or z directions. The translation in the y
direction is constrained by the lower surface around the rear seven-degree hole. It is on
this surface that a bolt will be seated which pulls the assembly together, thus constraining
translation in the y direction. There are also constraints on the surfaces inside the bolt
holes that will be used to provide clamping force. In the lower triple clamp there are six
holes that will have bolts going through them to provide this clamping force. The rigid
connection constraint was used on the inside surface of each of the clamping bolt holes.
This models the part as if there are bolts in the holes as there will be in the real part.
        The loading is based on a worst-case scenario of a head on collision. The force
applied to the lower triple clamp in this scenario is in the negative z direction acting on
the back surface of the fork tube holes. The direction is based on the moment created
Project Number 05912                                                           Page 58 of 77


about the top triple clamp. The force that is applied for this scenario is 8381 lb acting at
each of the fork tube locations. There is also the need to address the vertical force acting
on the lower triple clamp. The vertical force is acting in the positive y direction and
assumes a no slip condition between the triple clamps and the fork tubes. The force is
derived also from the worst-case scenario. This resulted in a force of 979 lb acting as a
surface force in the positive y direction on each of the fork tube holes.


Figure 12 is the constraint and loading schematic for the top triple clamp. The constraints
and loading positions are chosen on the basis of creating a model that most effectively
resembles how the forces will actually apply to the part.




               Figure 12: Constraint and Loading Schematic- Lower Triple Clamp


Based on the analysis, both parts are structurally sound with a force based on a 7G
impact. The industry standard for impact testing is no yielding due to a 3G impact.
Since both parts are below yielding due to a 7G-impact force, it is safe to say that at 3G’s
there is a substantial factor of safety. The industry specification information was
acquired though Derek Yuen of X-Test Incorporated. The fatigue limit was calculated
Project Number 05912                                                        Page 59 of 77


based on a cyclical 3G vertical input. The number of cycles with this very intense force
was 67000 cycles. Figure 13 shows the von Mises Stress based on a 7G horizontal
impact scenario on the top triple clamp. Figure 14 shows the displacement magnitude
based on a 7G impact scenario on the top triple tree. Figures A-1 through A-4 in
Appendix A show the von Mises Stress and displacement magnitude based on 7G and 3G
impact scenarios for the lower triple clamp.




Figure 13: Top Triple Clamp- von Mises Stress based on a 7G horizontal impact scenario
Project Number 05912                                                        Page 60 of 77




Figure 14: Top Triple Clamp- Displacement magnitude based on a 7G horizontal impact
                                     scenario

There were some preliminary design criteria that influenced the outcome of the triple
clamp designs. The decision to rake the front of the motorcycle out 7 degrees, and also
the use of 55-millimeter diameter top tube inverted forks, conversion to a mid-glide front
end, while also designing around the stock Harley Davidson Sportster frame. The stock
triple clamps are made of cast aluminum, so the team decided that the replacements
would be billet 6062-T6 Aluminum that is relatively easy to machine, polish and anodize.
The top clamp is 1.75 inches thick, while the lower is 2 inches thick.


The rake angle was defined by the 1-inch diameter hole in the rear of each clamp. This
hole has a steering shaft mounted through it, which assembles the triple clamps to
steering stem. This hole is at a 7-degree angle from vertical. The bearing mating
surfaces must also be perpendicular to the hole angle.


Conversion to a mid-glide front end in the design drove the center-to-center distance
between the fork tube hole locations. The mid-glide center-to-center distance is 8.065
inches; this drastically widens the front end of the motorcycle and in combination with
Project Number 05912                                                           Page 61 of 77


the larger diameter forks, it changes the styling of the motorcycle to look more like a big
bike.


The three-bolt pattern was chosen to distribute the clamping force evenly across the
thickness of the part. The design incorporates 5/16-18 socket head cap screws to apply
this clamping force to the steering stem and the fork tubes.


The final constraint is the triple clamps must be aesthetically pleasing. As the triple
clamps are a very visible surface of the motorcycle, they must look good while still being
structurally sound. Figure A-5 in Appendix A illustrates the top and lower triple clamp
designs.


Swing Arm
The team initially started designing a replacement swing arm for use on the 175th
chopper. The goal was to produce a swing arm that would be a direct replacement for the
stock component and be much more visually appealing. We started the design with the
goal of using 6061 T-651 aluminum as the construction material. Since 6061 is not a
direct replacement for mild steel, extra care was taken to retain as much material as
possible, and yet fit a 190mm wide tire. Since the goal was to produce a direct
replacement, the stock pivot bearings were designed around. They are the blue bearings
in Figure 15. The stock shock mounting points were utilized as well so that a stock ride
height could be retained if so desired.
Project Number 05912                                                          Page 62 of 77




                              Figure 15: Sportster swing arm
Since this component needed to be aesthetically pleasing we tried to design the chain
tensioner so that it was much less obtrusive. This was accomplished by utilizing two
“pull blocks” which the axle passes through. These blocks have threaded holes that allow
two socket head cap screws to be thread into them pulling the axle toward the back of the
bike and tensioning the chain. The green block represented in Figure 15 would be pinned
in place allowing the SHCS to pull against them as the chain was tensioned.


Ultimately the team decided that due to the size and complexity of the swing arm we
would only attempt to produce one if time allowed. This conclusion was based on the
ability to utilize the stock swing arm, with some minor cosmetic modifications.

Wheel Design
The first front wheel design the team developed is illustrated in Figure 16. The design is
made out of three pieces. The thicker piece that can be seen is from the wheel blank and
Project Number 05912                                                             Page 63 of 77


is the structural support of the wheel. The lighter colored piece is a decorative attachment
to the blank, created to emulate a tiger claw to go along with the tiger theme of the bike.
The attachment would have a corresponding piece on the opposite side of the blank. The
team first considered making the attachments out of aluminum; however, aluminum was
deemed not feasible as it is too heavy and too difficult to machine. The next idea was to
make the attachment out of composite; this too was deemed not feasible, as a mold would
have been exceedingly difficult to make. As a result, the team vetoed this design.
Additionally there was some speculation the design it self was not structurally sound and
would fail analysis. Therefore analysis was not performed on this wheel or hub.




                              Figure 16: Original wheel design
The finalized front wheel design is illustrated in Figure 17. The orange outlines are
present to increase the visibility of the cut details in the illustration. For analysis on the
wheel, the team used an impact load of 6Gs, a full compression load of 6Gs and a
maximum torque load of the braking force plus the tractive effort applied at the bead of
the wheel. The industry standard for testing impact loads and compression loads is 3Gs.
Project Number 05912                                                           Page 64 of 77


By using 6Gs we have allowed for a reasonable factor of safety. The material used for the
analysis was 6061 Aluminum, with a maximum yield stress of 40,000 psi and the
ultimate tensile stress of 45,000 psi. Calculations involved in this analysis are located in
Appendix B under Calculation set A.




                               Figure 17: Final wheel design

The rear wheel will stay solid with the exception of the mounting points for the rear hub.
A 5-bolt pattern was chosen because of the size of the hub and the amount of force
exerted on it. The loading for the analysis was performed in the same way as for the front
wheel. Figure A-11 in Appendix A illustrates the rear wheel design.



Wheel Hub
The wheel hub was analyzed by using of a torsion test. The break rotor bolt holes were
loaded and held on to by the wheel mounting holes; the same torque as was used for the
wheel was used. Figure 18 shows the wheel hub.
Project Number 05912                                                            Page 65 of 77




                                   Figure 18: Wheel hub
Drive
        The Sportster's stock drive line consists of a belt drive system made up of three
key parts, a front pulley, a rear pulley and a Kevlar belt. The front is a 28-tooth pulley
while the rear is a 68-tooth pulley. The team decided to eliminate the belt in favor of a
#530 chain. This was done for a couple reasons. A Belt, while providing a smoother and
quieter operation is much wider then a chain. The reduction in width is required in order
to fit a 190mm wide rear tire. The second reason for upgrading to a chain drive was to
increase the overall durability of the drive line. Chain drives can stand much harsher
applications of torque, and shock loading. The chain selected was based on the power
out put of the choppers engine. The first step in upgrading the overall drive line was to
determine a final drive ratio. The stock drive ratio is 2.43:1, which was calculated by
dividing the driven pulley by the drive pulley. The team decided to stay close to the
original final drive ratio since the new rear tire will be slightly smaller in diameter then
the stock tire, this alone combined with a 2.5:1 ratio would make the bike a little bit
easier to start off with while still maintaining a respectable top speed.
        The first component that required a redesign was the output sprocket. This is the
drive sprocket that attaches to the transmissions output shaft. Due to the size of the
retaining nut on the transmission output shaft, the out put sprocket had to be designed
much larger then typical front sprockets. Typical front sprockets are no larger the 16
Project Number 05912                                                      Page 66 of 77


teeth, while the one we designed was a 20 tooth. Figure A-10 in Appendix A illustrates
the 20-tooth sprocket.
Project Number 05912                                                   Page 67 of 77


Appendix A




  Figure A-1: Lower Triple Clamp- von Mises Stress based on a 7G horizontal impact
                                     scenario




  Figure A-2: Lower Triple Clamp- Displacement magnitude based on a 7G horizontal
                                  impact scenario
Project Number 05912                                                    Page 68 of 77




   Figure A-3: Lower Triple Clamp- von Mises Stress based on a 3G vertical impact
                                     scenario




 Figure A-4: Lower Triple Clamp- Displacement based on a 3G vertical impact scenario
Project Number 05912                                             Page 69 of 77




                 Figure A-5: Top and Lower Triple Clamp Design
Project Number 05912                                                    Page 70 of 77




                           Figure A-6: Impact loading




             Figure A-7: Von Mises Stress based on impact load in A-6
Project Number 05912                                                     Page 71 of 77




                           Figure A-8: Torsion loading




             Figure A-9: Von Mises Stress based on torsion load in A-8
Project Number 05912                                             Page 72 of 77




                           Figure A-10: 20-tooth sprocket




                       Figure A-11: Rear wheel design with hub
Project Number 05912                                                      Page 73 of 77


Appendix B
Calculation set A

Loads
F=m*a
W = 780 lbsf, bike plus rider
m = 780 lbsf / 32.1704 ft/s2 = 24.2459 lbsf s2/ft
a = 6 * 32.1704 ft/s2 = 193.0224 ft/s2
F = 24.2459 lbsf s2/ft * 225.1928 ft/s2 = 4680.00 lbsf

Torque
Tractive Effort-        P =  * m * t = 1 * 10.944 * 612 = 608.884 lbsf
                                R             11
≡ Overall mechanical efficiency = 1
m ≡ Overall gear ratio = 10.944 (1st gear)
t ≡ engine torque = 51 ft lbs = 612 in lbs
R ≡ tire rolling radius = 11 in
Braking Force-          F = m * a = Fr
                        Fr = fr * N
a ≡ 3 Gs = 96.5112 ft/s2
m = 24.2459 lbsf s2/ft
Fr ≡ Force of friction = 2340.00 lbsf
fr ≡ Coefficient of friction = .8
N ≡ Normal Force = 2925.00 lbsf

Total Torque = 608.884 + 2925.00 = 3533.89 lbsf
           Project Number 05912                                                                       Page 74 of 77


           Appendix C
           Weighted concepts evaluation: Fuel Tank


        Attributes             1           2           3         4        5                               TOTAL       Weights

1. Price                       X                                                      3           0          3         0.27

2. Uniqueness                  X           X                                          0.5         0         0.5        0.05

3. Design concept              X           X           X                              0          0.5        0.5        0.05

4. Ease of manufacture         X           X           X         X                    0           2          2         0.18

5. Fulfills project goals      X           X           X         X        X           0           5           5        0.45
                               0           0          0.5        2        5                                  11          1

                                               Figure C-1: Attribute comparison

                                 1                 2             3              4                5
           Price              >$1,000           <$1,000        <$700          <$400           No cost
                                      Looks as                              Looks as
                                                              Looks as
                         Look less   unique as a                            unique an       Most unique
                                                             unique as
            Uniqueness unique then a   standard                              average           tank
                                                            standard XL
                       "peanut" tank "peanut" XL                             custom         imaginable
                                                            custom tank
                                         tank                               choppers

                                                       Does not look
                                                                      Looks similar Looks exactly
                             Does not fit Does not fit like concept
                                                                       to concept    like concept
              Design        concept and concept, but drawings, but
                                                                        drawings,      drawings,
              Concept       does not look looks good on fits concept
                                                                     looks good on looks great on
                            good on bike       bike      and looks
                                                                           bike           bike
                                                        good on bike


                                                             Not on the
                                                                         Already on the Already on the
                              Custom                         market, but
             Ease of                                                      market, but market and
                            design and                        can be
            manufacture                                                    not readily      readily
                            custom built                    manufactured
                                                                            available      available
                                                              in bulk


                                                            Make a bike
                            Do nothing,                                    Make a bike Make a bike
                                                             that meets
           Fulfills project leaving a                                     that fits most that meets all
                                                            some of the
                goals       standard XL                                  of the goals of    goals of
                                                            goals of the
                             883C look                                     the project      project
                                                               project


                                               Figure C-2: Attribute rating scale
       Project Number 05912                                                                           Page 75 of 77


               Attribute           Weight  Stock Tank Commercial Tank Custom Tank
               Price                  0.27       5          3               1
               Uniqueness             0.05       3          4               5
               Design Concept         0.05       1          4               5
               Ease of manufacture    0.18       5          5               1
               Meets project goals    0.45       1          5               5
               Score                           2.91       4.36            3.18

                                Figure C-3: Alternative comparison




                                                                                                                      Purchase Aftermarket Tank
                                                            Purchase Custom Tank
Evaluate each additional concept against




                                                                                           Fabricate Tank
the baseline, score each attribute as: 1
= much worse than baseline concept 2 =
worse than baseline 3 = same as baseline
4 = better than baseline 5= much better
              than baseline



Sufficient Student Skills                            3.0                             2                        3
Sufficient Shop Equipment                            3.0                             2                        3
Economic Feasibility                                 3.0                             4                        5
Cost of Materials                                    3.0                             4                        5
Cost of Purchased Components                         3.0                             4                        5
Schedule Feasibility                                 3.0                             1                        3
Task Time                                            3.0                             1                        3
End user satisfaction                                3.0                             3                        1
Technology Feasibility                               3.0                             2                        3
Meets intermediate milestones                        3.0                             3                        3
Meets PDR requirements                               3.0                             3                        3
Meets CDR requirements                               3.0                             3                        3

Mean Score                                           3.0                            2.7                       3.3


Normalized Score                                   90.0%                           80.0%                    100.0%

                              Figure C-4: Pugh’s Method for fuel tank
       Project Number 05912                                                                             Page 76 of 77




                                                            Existing belt drive
Evaluate each additional concept against




                                                                                          Smaller belt drive
the baseline, score each attribute as: 1




                                                                                                                        Chain drive
= much worse than baseline concept 2 =
worse than baseline 3 = same as baseline
4 = better than baseline 5= much better
              than baseline


Sufficient Student Skills                            3.0                            3                            3
Sufficient Shop Equipment                            3.0                            3                            3
Economic Feasibility                                 3.0                            2                            4
Cost of Materials                                    3.0                            2                            2
Cost of Purchased Components                         3.0                            2                            5
Schedule Feasibility                                 3.0                            2                            4
Task Time                                            3.0                            2                            4
End user satisfaction                                3.0                            3                            2
Technology Feasibility                               3.0                            3                            5
Meets intermediate milestones                        3.0                            3                            4
Meets PDR requirements                               3.0                            3                            4
Meets CDR requirements                               3.0                            3                            4

Mean Score                                           3.0                           2.6                           3.7


Normalized Score                                   81.8%                          70.5%                        100.0%

                              Figure C-5: Pugh’s Method for driveline
Project Number 05912                                                        Page 77 of 77


References
1. “ANSUR Military Database.” United States Military

2. Arabe, Katrina. “On a roll, motorcycle industry hums along.” Thomasnet Industrial
   News Room. 28 January 2005.
   http://news.thomasnet.com/IMT/archieves/2005/01/on_a_roll_motor.html

3. Coben, J., Steiner, A. and Owens, P. “Motorcycle related hospitalizations in the
   United States, 2001.” American Journal of Preventive Medicine. 2004: 335-362.

4. Freedman, M. and Davit, P.S.K. “Improved conspicuity to the side and rear of
   motorcycles and mopeds.” Journal of Safety Research. Winter 1984: 176-177.

5. Harley-Davidson Motor Company. Harley-Davidson Motor Company. 3 December
   2004 through 17 February 2005. www.harley-davidson.com

6. Hurt, H.H., Ouellet, J.V. and Thom, D.R. “Motorcycle accident cause factors and
   identification of counter measures.” Traffic Safety Center, University of California.
   January 1981

7. Kern, Walter. “Choppers.” About.com 9 December 2004
   http://motorcycles.about.com/cs/choppers/a/choppers.htm

8. Street Chopper. Primedia Publication. 7 December 2004 www.streetchopperweb.com

9. The Student’s EDGE: An Engineering Design GuidE. E. Hensel and P. Stiebitiz.
   2005 Rochester Institute of Technology. 3 December 2004 through 17 February 2005
   http://designserver.rit.edu/

				
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