Alloy

An alloy is a metal mixed with other elements to improve its properties. Steel itself is an alloy of iron and carbon. In motorcycle talk, though, 'alloy' usually means aluminium alloy, and sometimes magnesium alloy.

Aluminium alloys are used for cast or forged wheels, frames, swingarms, engine cases, cylinders and many small parts. They are much lighter than steel, conduct heat well and resist corrosion, but are generally less stiff and less tolerant of repeated bending, so parts are made thicker or shaped differently.

Inspect alloy wheels for cracks and dents after hard hits, as they cannot be safely straightened the way a spoked steel rim sometimes can. Use the correct torque on alloy threads, which strip more easily than steel.