Tyre size

What % speed difference at same eng revs would a change in tyre size from 10.00 x 20 to 9.00 x 20.
Any help much appreciated.

Maurice.

Off the Top of My Head 8-10%..

This is handy

spicerparts.com/calculators/engine-rpm-calculator

And this one

tiresize.com/calculator/

Only 37mm difference in height -1018 vs 1055mm. It will only change your engine speed by about 65 rpm at 80kmh. About 3.6% or it will drop your road speed at 80kmh by about 2,5kmh at the same revs. All this is needle width stuff and other factors such as cost, availability and originality probably have more bearing on your choice.

Lang

Thanks very much Lang
Maurice