Crankset
The crankset (in the US) or chainset (in the UK) is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain or belt, which in turn drives the rear wheel. It consists of one or more sprockets, also called chainrings or chainwheels, attached to the cranks, also called arms or crankarms, to which the pedals attach.