Young Ron Wood pulled a bit of weight of the Flywheel , Steve . Would be common on any race machine . Maybe not quite so much of , for the Dirt . The flywheel Effects what keeps it smooth , and the wheel spinning evenly . to light , and it'd STOP if you shut the Throttle . The infernal CLUTCH assembly , and Wheel weight , being rotateing masses , are all relevant too . getting real scientific , The relevant masses ( proportion of total rotateing ) would be of some relavance . These Ducati Bevels didnt allways run flywheels , and some suckers saying the D type ( Jag ) Le Mans , with its 3 plate ( multi plate ) clutch , ran no flywheel . Infernal balance shafts are horrible contrivances in that respect . The Hamonics in the Cam Drive Gears , in the DFV Cosworth are what led young Kieth to go a bit overboard with the Norton P95 Challenge . Brabam Repco V-8s had gear drive failure through harmonics in the G.P. engines also . No a damn CAMSHAFT would be a sensible place to put a bit of flywheel ( mass ) except Top weight rolls a bike out of a corner , sideways on the dirt . Much the same on Tarmac , Id suspect . Those sooper Bike suckers do mighty highsides if they cock it up .