On Wednesday, July 15, 2020 at 6:21:55 PM UTC-5 Joel Stern wrote: > I was asked to get my tire radius and I have no cluehow to do it. > > Jason gave the straight math version from the rim and tire sizes, which is fine for most purposes.
If you want to get it more precisely, here are two approaches. For both of them, if you want it accurate for when you are on the bike, you'll want some help. Note that the results are tire pressure dependent. With the bike as close to perpendicular to the ground as you can make it, measure the distance from the ground at the center of the tire contact patch to the center of the axle. Measure both sides several times and take the average of all the measurements (throwing out any oddball outliers if you have them). The old Avocet Cyclometer prescribed method: Set the front wheel so the valve stem is at the very bottom and mark a line on the ground at the center of the tire contact patch, where the valve stem is. Ride the bike forward in a straight line one revolution of the front wheel, and mark another line where the center of the contact patch (and the valve stem) now are. Measure the distance between the two marks. Divide that distance by 2*Pi, and that's your radius. (For more accuracy, repeat that measurement several times and take the average.). It's possible to put a chalk line on your tire and do this yourself, without help. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/83f4113d-703e-4787-b5ee-276c56429957n%40googlegroups.com.
