The effective speed
depends on tire size, differential, rotations per minute, gear and gearbox
ratios. How much
exactly this effective speed is can be calculated here below.

This calculation uses the
following formulas : Perimeter = ((Tire width X Series / 100) X 2 + Rim size X 25,4) X Pi Speed = ((Rotations
per minute / Differential /
Gear ratio) X (Perimeter / 100 X 60) / 1000