Motorcycle Glossary

Bearing

In Turkish: Rulman

In short

A bearing is a machine element that reduces friction between a rotating shaft and a fixed housing using balls or rollers.

Motorcycles use bearings in the wheels, crankshaft, gearbox, steering head and swingarm. Ball bearings are identified by standard codes such as 6201 (12 × 32 × 10 mm) and 6202 (15 × 35 × 11 mm). Suffixes show the sealing: 2RS has rubber seals on both sides, ZZ has metal shields on both sides.

Symptoms: a rumbling noise, sideways play in the wheel, a rough feel when turned
Wheel bearings are usually replaced in pairs together with the spacer
When fitting, press only on the outer (or interference-fit) race with a suitable driver