Suspension Travel: Bump and Rebound
Suspension travel is the permitted wheel or component movement between its compression and extension limits.
Bump or compression
Bump, also called jounce or compression, is motion in which the wheel moves upward relative to the body and the spring generally shortens. The available bump travel must accommodate road inputs, cornering, braking, payload, and body motion before the suspension reaches its compression stop or another clearance limit.
Rebound or extension
Rebound, also called droop or extension, is motion in the opposite direction. Rebound travel helps the tire follow a falling road surface and allows the body and wheels to move relative to each other. It ends at a rebound stop, damper limit, strap, joint limit, or other mechanical constraint.
Which travel is being quoted
Wheel travel, spring travel, and damper-stroke travel are not interchangeable because linkage geometry creates a motion ratio. Total travel is also not necessarily divided equally around normal ride height, and usable travel can change with load or adjustable suspension settings.
For wheel paths, motion ratios, and alignment changes, see Suspension Kinematics and Vehicle Dynamics. Spring and damper functions are covered in Suspension Springs and Suspension Dampers.