Question regarding tire circumference

[gsxrche]

First, mesaure the circumference of each tire on the rim with air in it, and of course at the pressure you ride on.  Tires gain a little with air in them, some more than others.

Then, do the math to calculate radii for these measurements, using the formula:
                    r = c / 2pi.

The difference between front tires can be used directly.  The rear will be different.  On the gsxrs, the ratio works out to about 1 mm in shock height = 7 mm at the axle, as measured then calculated using radii of swing-arm pivot, shock centre, and axle in the middle of the adjustors.  This should not be too different for CBRs, ZXs, and YZFs.  Cheers

[endoracing]

I would think that the fork angle would play a part as well... 5mm down on the fork wont lower the bike 5mm unless the forks are straight up and down...

Just a thought...

[tyrebuster]

Does anyone know is there is a place that has the circumfrence or overall diameter of motorcycle tires listed? I know for car tires any of the major manufactures will have the overall diameter and loaded tire diameter listed in their product guides.

[chris_chops]

Dunlop went from a 65 profile front slick to a 70 profile. Do I drop 5mm on the forks to make up the difference or is there some formula that I need to use to calculate the exact amount? Much appreciated.  :)

Drop your forks................but not too hard.  Merry Christmas Shogu.  Be advised, D-Bag club meeting coming soon.  NO BOWLING ALLOWED!!!!!!