BIKE TIRE TUBE SIZES
Jan 11, 2011 | By Lindsay Tadlock
Lindsay Tadlock began writing in 2010. She has worked as a personal trainer for the last 3 years and is
looking to share her fitness and nutrition knowledge in her writings. She graduated from Texas A&M
University in 2000 with her Bachelor of Arts in finance and worked for 7 years as a commercial lender.
When you buy a bike and ride frequently, you will eventually have a flat tire and need a replacement.
Having a spare tube as part of the repair kit is critical for emergencies. When buying a spare tube, you
need to know your tire's specifications.
The size of the tube is marked on the box. This has to be matched with the tire size. The size of the tire is
printed on the sidewall of the tire. This will typically be a combination of two numbers separated by the
Tire Sizes Look for the Perfect Tire by Size. Tire Rack is Your Online Source. www.TireRack.com
Diameter is represented by the first number on the sidewall. The typical sizes are 26 inches and 700 mm.
When making the purchase, ensure that the diameter of the tire is the same as that of the tire.
The width number is the second number on the sidewall of the tire. Sometimes the second number is not
just one number -- it can be a range. For example, 700x18-23 means that this tube will fit any tire with a
width measuring 18 mm to 23 mm. Two ranges might available. For example, 18-23 and 23-25. In this
case, it is better to choose the tube with a lower range. This will be lighter for the bike.
The tubes generally are available with three valve styles: Dunlop, Presta and Schrader. Presta valves are
narrower. They have no internal springs for keeping it closed, rather they rely on the inflated internal
pressure. Schrader valves are mostly found on car tires. A removable core inside the valve uses a spring
assembly to shut the valve. A Dunlop valve is a variation of the Schrader. This valve has not been
commonly used for many years. Choosing the wrong valve can lead to the valve not fitting the rim of the
tire or it can make your bike more prone to flat tires.
Seamless tubes are molded of butyl or latex rubber. Latex was previously used on all tubes but now most
inner replacement tubes are made with butyl rubber. Latex tubes are more supple and have slightly
enhanced handling characteristics. However, these are more expensive and are not able to hold air for as
long as the butyl rubber.