Suspension school · Damping Adjustments

Rebound In Depth

The red dial that decides whether your tyres stay on the ground

Rebound damping controls how quickly the suspension re-extends after being compressed. The adjuster is almost always red, sitting at the bottom of the fork's right leg and on the body or piggyback of the shock. Of every dial on the bike, this is the one that most decides whether your tyres stay in contact with the ground, and it is the one worth learning to feel first.

Compressed springs push back hard. A fork at 100 psi deep in its travel is trying to return with serious force, and rebound damping is what meters that return into something the bike and rider can use. Too little damping and the stored energy comes back as a kick. Too much and the suspension cannot recover before the next bump arrives.

Car Park Tests That Actually Work

• Fork push test. Stand beside the bike, front brake on, push down hard through the bars and let go abruptly. The fork should chase your hands back up promptly, settle at full extension and stop. A visible bounce past the top, or a clunk, means rebound is too fast. A lazy, syrupy return means it is too slow.
• Kerb roll. Ride off a kerb at walking pace, seated and relaxed. Each end should compress once, return once, done. If the bike keeps nodding afterwards, rebound is too fast. If it stays squatted and feels dead, too slow.
• Balance check. In the same kerb roll, feel whether the bike stays level as it recovers. If the front pops up before the rear, or the rear pushes the saddle into you while the front is still down, the two ends are recovering at different rates and want matching.

Car park tests get you close, but the trail makes the final call, and it does so through two very distinct symptoms.

Packing: The Too-Slow Symptom

When rebound is too slow the suspension cannot fully re-extend between closely spaced hits. Each impact starts from deeper in the travel than the last, so the spring is firmer, the ride gets progressively harsher, and the bike sits lower and lower. This is called packing down. The classic tell: a run of braking bumps or repeated roots feels fine for the first two or three hits, then rapidly turns hard and skittery.

Packing is sneaky because it feels like harshness, so riders instinctively soften compression or drop air pressure, which makes nothing better. If harshness builds through a rough section rather than being present from the first hit, think rebound first, and open it (more clicks out from closed) by one or two clicks.

On an eMTB there is a second place packing shows up: technical climbs. The rear wheel needs to return to the ground between roots and ledges to keep motor torque hooked up. A packed rear end leaves the wheel light exactly when you need traction, and the symptom is a wheel that spins up or skips on steps it should have cleaned.

Bucking: The Too-Fast Symptom

When rebound is too fast the bike feels tall, springy and nervous. The rear kicks up off jump lips and square edges, sometimes hard enough to pitch you forward. The front skips and chatters under braking instead of biting. You may hear or feel a faint top-out knock as the suspension slams to full extension. Grip suffers because the wheels spend their time being fired back at the ground rather than following it.

If the bike bucks on the lip of a jump, or the back end steps sideways off a fast square edge, add rebound damping at the shock, one or two clicks towards closed. On four-way dampers with separate high-speed rebound there is a subtlety here, covered in the HSR and LSR article.

Why Rebound Tracks Spring Pressure

The stiffer the spring, the harder it pushes back, and the more damping is needed to control the return. This is why every manufacturer's setup table hands heavier riders fewer clicks from closed. Marzocchi's Z1 and Z2 tables run from 13 clicks out for the lightest riders down to 1 click out for the heaviest. Fox keys its GRIP X2 rebound recommendations to rider weight, and its 2025 onwards Float X2 shock recommendations directly to air pressure: the more psi in the can, the fewer rebound clicks from closed.

The practical consequence: rebound is not set and forget across pressure changes. If you add or remove meaningful air, say 10 psi at the fork or 20 psi at the shock, re-check rebound. As a rough guide, expect about one click of change for each step like that, moving in the same direction as the pressure. More pressure, fewer clicks from closed.

Fork and Shock Do Different Jobs

The fork's rebound is mostly about front grip and steering trust. The front wheel has to extend quickly into holes and stay weighted over off-camber roots, and a packed front end washes out with very little warning. When in doubt, err slightly fast at the fork, keeping it just below the point where it starts to chatter under braking.

The shock works through the frame's leverage ratio, with the rear wheel typically moving around two and a half to three times faster than the damper shaft, and it carries most of the rider plus most of the eMTB's extra mass. Its rebound governs how the bike leaves the ground off lips, how it recovers in berms and, on an eMTB, how the rear wheel keeps finding drive on broken climbs. Bucking problems are almost always solved at the shock, not the fork.

Where to Start

• Set rebound to this calculator's recommendation, which follows the manufacturer's pressure and weight tables.
• If you fall between table rows, choose the faster setting (more clicks out) when grip and tracking matter most, the slower one when jumps and big hits dominate.
• Re-check with the kerb roll after any pressure change.
• Fine-tune on the trail with the bracketing method, two clicks at a time, one end of the bike at a time.