crankshaft is a shaft driven by a crank mechanism, consisting of a series of cranks and crankpins to which the connecting rods of an engine is attached. piston is a component of reciprocating engines. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. Crankshafts are usually made of carbon steel and developed separately according to different motorcycle models The main material of the piston is aluminum alloy, which is composed of piston ring, piston body and piston pin. You can buy accessories separately for maintenance.We also provide crankcase and crankcase cover and other supporting products. You can combine the products for better sales.Our products are applicable to mainstream motorcycle brands, such as Suzuki, Honda, Kawasaki, Yamaha, Bajaj, Akt, keeway, etc