CLUTCH PLATES

A Motorcycle Clutch is the tool that connects or disconnects power made by the engine to the transmission. The clutch is how a rider isolates the transmission from the rear wheel to stop the bike from driving forward. The clutch is a series of spring-loaded CLUTCH PLATES or FRICTION PLATES that, when pressed together(engaged), act as one to connect the crankshaft to the transmission(and rear wheel). To change gear, a rider uses the clutch to isolate the crankshaft from the transmission, selects a new gear and releases the clutch so power resumes to the rear wheel. 

So the Clutch is very important, you rely on the CLUTCH PLATES or  Friction Plates to connect the Engine power to the rear wheel and drive the bike forward.