Suspension

Suspension lets the wheels move up and down relative to the frame so that the tyres stay in contact with the ground over bumps, while the rider and chassis are isolated from impacts. On a motorcycle it consists of the front fork and the rear swingarm with one or two shock absorbers, often with a linkage.

Each unit combines a spring, which carries the weight, and a damper, which controls movement. Key settings are spring preload (which sets sag), compression damping and rebound damping. Many modern bikes also have electronic semi-active suspension.

Good suspension improves grip, braking, comfort and safety. Set sag for your weight first, service fork oil and shock at the intervals, and keep seals and linkage bearings clean and greased.