Most riders are riding their suspension completely wrong. The factory settings on most bikes are a compromise designed for a 75-80kg "average" rider doing "average" terrain. If that's not you — and it probably isn't — your suspension needs setting up for your weight, your style, and your trails.
This guide covers everything: sag, air pressure, rebound, compression, and the high-speed/low-speed tuning that most riders never touch. Take 20 minutes after reading this and your bike will feel like a different machine.
Step 1 — Set Your Sag
Sag is the amount your suspension compresses under your body weight when you're in your normal riding position. It's the foundation of everything else — get the sag wrong and no amount of rebound or compression tuning will fix it.
Measure Your Sag — Fork
Put a zip tie around the fork stanchion (the shiny inner tube) and push it down against the wiper seal. Get into your normal riding position on the bike, weight on both feet as you would on a trail, and gently dismount. The gap between the zip tie and the wiper seal is your sag measurement.
Target sag by riding style:
- XC: 15–20% of fork travel
- Trail: 20–25% of fork travel
- Enduro: 25–30% of fork travel
- DH: 30–35% of fork travel
For a 150mm fork: trail sag target = 30–37mm. Add or remove air pressure (Schrader valve at the top of the right leg) until you hit your target. More air = less sag (stiffer). Less air = more sag (softer).
Measure Your Sag — Rear Shock
Same process on the shock. Measure total shock stroke first (usually printed on the shock body, e.g. "55mm stroke" means the shock moves 55mm). Target:
- XC: 15–20% of shock stroke
- Trail/Enduro: 25–30% of shock stroke
- DH: 30–35% of shock stroke
For a 55mm stroke shock, enduro target = 13–16mm. Add or remove air at the shock's Schrader valve. Air shocks: adjust with a shock pump (normal bike pumps have too much dead volume). Coil springs: adjust pre-load with a spanner — you may need a different spring rate for your weight.
Step 2 — Set Rebound Damping
Rebound controls how fast the suspension returns to its full length after being compressed. Too fast and the bike bounces around. Too slow and it "packs down" (gets progressively smaller and doesn't work properly over successive bumps).
Set Fork Rebound
The rebound adjuster is typically the red dial at the bottom of the right fork leg. Turning clockwise (right) increases rebound speed (faster return). Turning counter-clockwise (left) slows it down.
Test: Start with the dial fully clockwise (fastest). Ride over a medium bump. If the fork bounces you up off the saddle, slow it down. Keep slowing until the fork returns smoothly but doesn't bounce. A good starting point for most riders is 10–15 clicks from the open (fastest) position.
Set Shock Rebound
Same process on the shock — typically the red dial at the bottom of the shock body. Same principle: too fast and the bike buckers, too slow and it packs down. The rear usually needs slightly faster rebound than the fork because the rear wheel hits every bump the front wheel hits, plus the bike's weight is partly over the rear.
Step 3 — Compression Damping
Compression controls how fast the suspension compresses when it hits something. This is where it gets slightly more complex because modern suspension has both low-speed compression (LSC) and high-speed compression (HSC) adjusters.
Low-Speed Compression (LSC)
Low-speed compression doesn't mean low bike speed — it means slow shaft movement. LSC controls how the suspension behaves when the bike compresses slowly: cornering loads, weight transfer on braking, and seated pedalling. More LSC = more support in corners and less bob while pedalling. Less = more plush, more active over small bumps.
Setting: Start with fully open (least compression) and add compression until pedalling bob becomes tolerable on climbs. Most riders need only a few clicks of LSC. Don't close it completely or you'll lose small-bump sensitivity.
High-Speed Compression (HSC)
HSC controls what happens when the suspension is hit fast and hard — rock gardens, big drops, harsh braking bumps. More HSC = better control over big hits but harsher overall feel. Less = more sensitive but can bottom out on big impacts.
HSC is typically adjusted with a large hex bolt (usually requires a 4mm or 5mm hex key) rather than a click dial. It's less frequently changed than LSC — set it once and leave it. Start in the middle and adjust based on whether you're bottoming out on big hits (more HSC) or feeling harsh small-bump impact (less HSC).
Troubleshooting
| Symptom | Likely Cause | Fix |
|---|---|---|
| Bike bounces over bumps | Rebound too fast | Slow down fork/shock rebound |
| Suspension packs down over successive bumps | Rebound too slow | Speed up fork/shock rebound |
| Bottoming out on big hits | Too much sag / too little air | Add air, check sag, add HSC |
| Harsh, chattery feeling over small bumps | Too little sag / too much air | Remove air, reduce LSC/HSC |
| Excessive pedalling bob | Not enough LSC | Add LSC (or use firm mode for climbs) |
| Front feels vague in corners | Fork rebound too slow, or too much sag | Speed up rebound slightly, reduce sag |
| Rear wheel skipping over rocks | Shock rebound too fast | Slow down shock rebound |
| Bike feels rear-heavy on descents | Rear sag much higher than front | Rebalance sag front to rear |
Token Tuning (Air Forks)
Volume spacers (tokens) in the air chamber of your fork and shock affect the "ramp up" — how progressively the suspension gets stiffer as it uses more travel. More tokens = more progressive (better end-of-travel support, harder to bottom out). Fewer tokens = more linear (uses full travel more easily, can feel softer throughout).
This is an intermediate adjustment requiring removal of the top cap and adding/removing tokens. Most riders don't need to touch this if their sag and damping are correct. If you're consistently bottoming out despite correct sag, adding a token is the next step. If you never use your full travel, remove a token.
Set your sag correctly. That's 80% of what matters. Once sag is right, set rebound at a comfortable medium setting and ride. You'll feel immediately if you need more or less. Don't try to perfect every dial at once — one variable at a time, and test on familiar terrain so you can feel the difference clearly. Most riders who "don't like how their suspension feels" just need their sag set correctly. It's that impactful.