B Bob A New member Sep 8, 2009 #2 There is a difference in tire circumference. You can use a tape measure around the tire or use a chart from this site. http://www.sheldonbrown.com/cyclecomputer-calibration.html
There is a difference in tire circumference. You can use a tape measure around the tire or use a chart from this site. http://www.sheldonbrown.com/cyclecomputer-calibration.html