Home → glossary → Rebound

Rebound

The speed at which suspension returns to its extended position after being compressed.

Published January 1, 2025

Definition

Rebound damping controls the speed at which a fork or rear shock returns to its fully extended position after being compressed by an impact. It is one of the two primary damping adjustments on mountain bike suspension, alongside compression damping.

How It Works

When suspension compresses over a bump, energy is stored in the spring. Without damping, that energy would release instantly, causing the wheel to bounce off the ground like a pogo stick and become uncontrollable.1 The rebound damper — typically an oil-filled circuit with adjustable valving — slows this return movement to a controllable rate.

Rebound is adjusted via a dial or knob, usually located at the bottom of the fork lowers or at one end of the rear shock. The adjuster is marked with a + / − symbol or, on RockShox components, a tortoise (slow/more damping) and hare (fast/less damping) icon.2

Too Slow (Over-Damped)

If rebound is too slow, the suspension cannot extend fully before the next impact. Over successive bumps it progressively compresses further — a phenomenon called packing down — resulting in a harsh ride, poor traction, and the wheel skipping between obstacles rather than tracking the ground.3

Too Fast (Under-Damped)

If rebound is too fast, the suspension springs back faster than the wheel can follow the ground, causing the bike to buck and feel uncontrolled, especially on repeated hits.

High-Speed vs Low-Speed Rebound

Higher-end forks and shocks separate rebound into two circuits:

  • Low-speed rebound (LSR): Controls return speed during slow, sustained movements — general trail undulations, pedaling forces, and body movement. This is what the external adjuster knob primarily controls.
  • High-speed rebound (HSR): Controls return speed after fast, sharp impacts — large hits, drops, and rock gardens. Some suspension units offer a separate adjuster for this circuit.

How to Set It

A common baseline method:4

  1. Start with rebound fully closed (slowest)
  2. Compress the fork or shock by hand and release
  3. Open (speed up) rebound one click at a time until the suspension returns as fast as possible without the wheel jumping off the ground or the front end bucking
  4. Test on trail and adjust — if the bike feels harsh and packed down, speed up rebound; if it feels bouncy and uncontrolled, slow it down

Note: if you change air pressure or spring rate, rebound will need to be re-checked — a stiffer spring produces faster rebound and may require more damping.2

See Also

References

Footnotes

  1. BikeRadar, "How to adjust the compression and rebound settings on your mountain bike" https://www.bikeradar.com/advice/workshop/compression-and-rebound-adjustment ↩

  2. bike-components.de, "Rebound & Compression: What's What in MTB Suspension" https://www.bike-components.de/blog/en/guides/rebound-compression-whats-what-in-mtb-suspension/ ↩ ↩2

  3. Justia Patents, "Dampers for Mountain Bikes" https://patents.justia.com/patent/20110127706 ↩

  4. Enduro MTB Magazine, "Setup Guide – How to adjust your mountain bike suspension" https://enduro-mtb.com/en/setup-guide-mtb-suspension/ ↩