Re: Why does the motorcycles rear wheel spins while revving the engin?
Technical explanation: Cold bike, cold oil, cold parts.
Metal is cold therefore the clearances between clutch and transmission components are tight hence will have the tendency to let some energy be transferred to the transmission gears. Cold oil is more viscus and with the tighter tolerances enough energy is transferred to the output shaft therefore turning wheel when cold.
Bike heats up everything expands and the oil flows, the rear wheel will stop spinning with the engine running and in neutral