Ross Rock Machine Aluminum Mountain Bike Ross Aluminum "Rock Machine" Oversized 7000 Series Welded Aluminum Frame (26" x 18") with Top Tube Cable Routing and Replaceable Derailleur Hanger. Unicrown TIG Welded Steel Fork, Threadless. Alloy Cantilever Brakes and Levers. 21 Speed Shimano SIS Derailleurs with Gripshift MRX-170 Twist Shifters. Silver 170mm Cranks with 28 x 38 x 48 Tooth Chainrings. Rigida Alloy Rims, 14 Gauge Spokes and Quick Release Alloy Front Hub. 26" x 2.1" Black Knobby Tires. Alloy Quick Release Seat Pin and Alloy Seatpost. Extras: Water Bottle and Water Bottle Cage, Kickstand, and Bar Ends. Low Price - Click Now!