Motorcycle Crankshaft Definition and Example

Definition: A reciprocating engine uses a crankshaft to covert vertical movement by pistons within a cylinder, to a rotating force.

Alternate Spellings: crank

Examples:

Due to the differing lubrication systems, 2-stokes and 4-strokes typically have different crankshaft designs. The 2-stroke crankshaft generally uses two flywheels connected by a steel pin which is a tight, press fit into each flywheel.

However, before the assembly is pressed together, a connecting rod and bearing must be situated on the pin. As the two halves are pressed together, the connecting rod is then entrapped between the two flywheels.

On 4-stroke crankshafts, the connecting rods are generally split at the crank pin, or big end bearing location, and bolted together (see photograph of the connecting rod).