Though most bicycle tires are measured and labeled in inches, road tires like the 700c and 650c are measured and labeled in mm. and tire diameter (the size of your tire converted to millimeters) Wheel diameter = (rim diameter) + (tire diameter * 2). 700c). Wheel circumference = Wheel diameter * PI. ... 650 x 32A: 1854: Find tires… (a.k.a. "A" was originally a tire about 30 mm wide, so the 650A rim is pretty large, 590 mm. Thus for practical purposes the size of these two wheels rim diameter is only 12mm different. The world of mountain biking has taken this and run with it, offering four different sizes for different disciplines – 24in., 26in., 27.5in., (a.k.a 650b) and 29in. Since the tire wraps around your rim, the wheel diameter includes the tire on both sides (thus the multiplication by 2). The second number (32) is the tire width in millimeters. In this example: 650 x 32A, the first number (650) is the overall diameter of the tire in millimeters. ETRTO (European Tire and Rim Technical Organization) sizes are given for all tires. Thus they are very close to the same size… The absence of a letter indicated a narrow tire; "A", "B" and "C" indicated increasingly wider tires.

If the tire conversion charts aren't for you don't forget to try out our tire calculators for individual tire conversions. Every tire size is listed with its metric measurements and inch size equivalent. If you are facing and should change the tires on your bike, it is important that you choose the right bicycle tire sizes for your bike wheels. In contrast, road cycling and triathlon have slowly but surely eliminated 650c, leaving 700c as the lone size for performance bikes. Browse our tire conversion charts by wheel size or tire diameter to find the tire conversion you're looking for. A 650b wheel is one that’s about 27.5 inches in diameter, when measured from tyre edge to tyre edge. The letter A indicates that the rim is 590 mm. The number is the nominal outsidediameter of the tire the rim was originally designed for. In a traditional 650B conversion, where the 650B tires are swapped into a 700C road bike, most authorities agree that a fat, 42mm-47mm 650B tire will approximate a 700 X 28-30mm wheel and tire’s diameter. Before I get started it’s important to note that a 650C has a rim diameter of 571mm and a 26″ Wheel for our purposes has a rim diameter of 559mm. Leigh holds bachelor's degrees in anthropology and linguistics from the University of Washington. Each tire size is very variable depending on the type of bicycle tire you want, and depending on what type of bike you have. The Raleigh Tamland Two with traditional 700c wheels and 40mm tires. Bike tire size.