Rebound & Compression Damping: Setup Guide for MTB
Air pressure and SAG decide how much travel you use. Rebound and compression decide how the suspension behaves while doing so: how fast it extends and how strongly it resists compressing. If you understand both, you can make your suspension calmer and safer without swapping parts.
What rebound and compression do
The air spring (or coil spring) stores energy as it compresses. Without damping it would release that energy at once and the wheel would bounce like a rubber ball. Damping slows this movement with oil forced through small openings.
- Rebound: slows the extension. It determines how fast the wheel returns to its starting position after a hit.
- Compression: slows the compression. Many forks and shocks split it into two ranges: low-speed (LSC) acts on slow movements such as braking, cornering, sprints and bobbing. High-speed (HSC) acts on hard, fast hits such as edges, rocks and landings.
Which adjusters your suspension has is in the manufacturer's manual. Some forks only have rebound and a lever for compression, others four separate adjusters.
In which order to adjust
- Air pressure and SAG first. Without a suitable SAG all damping settings are pointless. How that works is in the guide How to set SAG; the suspension calculator gives starting values.
- Then rebound, first on the fork, then on the shock.
- Then compression in small steps.
- Change only one setting at a time and ride the same test route. Write down the clicks, for example in My bike, so you can always return.
Setting rebound
Starting point: Turn the adjuster fully closed (without force, until it stops) and count the clicks outward from there. That way you can restore any setting exactly later. Begin in the middle of the adjustment range.
- Fork: Push down on the bars with your weight to compress the fork deeply and then release. The fork should return in one movement without bouncing and without lifting the front wheel off the ground.
- Shock: Sit on the bike, compress deeply and unload abruptly. The rear wheel should return without bouncing. In a test off a kerb (“drop”), the rear end should extend after landing without hopping.
- Too fast: The wheel skips or “kicks” after hits, gets restless and loses traction. Close the rebound (slower).
- Too slow: On repeated hits the suspension stays down and sinks deeper (“packing”). The bike feels sluggish and harsh. Open the rebound (faster).
Rule of thumb: More air pressure or a firmer spring means the suspension extends faster. If you raise the pressure you therefore usually need slower rebound. If you weigh more, you need more pressure and with it more rebound damping.
Setting compression
Compression mainly changes how the bike feels under braking and when pedalling out of the saddle:
- Low-speed compression: More damping supports the suspension under braking and in corners (the front dives less) and reduces bobbing when pedalling. Too much makes the suspension harsh and robs traction on small bumps.
- High-speed compression: More damping helps on hard hits and landings and stops the travel being used up too quickly. Too much gives a harsh, slapping feel.
- Climbing or lever: The climb switch (or platform mode) greatly increases low-speed compression and calms the rear end when pedalling. Open it again for descents.
Start with the manufacturer preset or the middle, change compression in single clicks and ride the same route to compare. If you do not use the travel, the air pressure is usually too high or the compression too closed; if the fork bottoms out, a volume spacer can help (Volume spacers).
Symptoms and remedies
| Symptom | Likely cause | Remedy |
|---|---|---|
| Front wheel skips after roots | Front rebound too fast | Close rebound by one to two clicks |
| Suspension sinks on repeated hits | Rebound too slow | Open the rebound |
| Rear wheel “kicks” after jumps | Rear rebound too fast | Close the rear rebound |
| Fork dives strongly under braking | Low-speed compression too open | Close low-speed compression |
| Rear end bobs when pedalling | Little low-speed compression, platform not active | Use the climb lever, close LSC slightly |
| Harsh and buzzy on small hits | Compression too closed, too much pressure | Open compression, check pressure |
| Suspension often bottoms out | Too little progression, too little pressure | Check pressure, add a volume spacer if needed |
Frequently asked questions about rebound and compression
What does rebound do?
Rebound controls how fast the fork or shock extends again after compressing. Too fast and the wheel skips; too slow and the suspension gradually sinks deeper on repeated hits.
Where do I start with rebound?
Set the SAG first. Then close the adjuster fully and count clicks from there until the fork returns after a push on the bars without bouncing. More air pressure needs slower rebound.
What is compression damping for?
Compression damping slows the suspension as it compresses. Low-speed compression supports under braking, in corners and when pedalling; high-speed compression handles hard hits. It does not replace correct air pressure but complements it.
Calculate starting values for your suspension →