Cranks & Cotter Pins
The bicycle crank, crankset, bmx crank, bike crank and chainset, are the components of a bicycle drivetrain that converts the up and down motion of a rider's legs into the rotational motion used to drive the chain. This in turn drives the rear wheel. It consists of one or more sprockets, also called chainrings or chainwheels attached to the cranks to which the pedals attach. It is connected to the rider by the pedals, to the bicycle frame by the bottom bracket, and to the rear sprocket, cassette or freewheel via the chain.