How To Use Rebound Damping

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There’s more to setting rebound damping than bouncing your suspension a few times in the driveway until it “feels right”. Using the right amount of rebound damping is one of the best ways to improve the comfort and stability of your ride. Check out our video below to get started.

Why is setting rebound more complicated than just sitting and bouncing until it “feels right”?

The short answer: what feels right in your driveway when you’re stationary is not necessarily what is right when you’re moving rapidly off-road.

Your rebound damping adjustment is meant to give you comfort and control when you’re moving over various kinds of terrain.

Rebound isn’t just the “bounce” – it’s literally what allows your shocks to return to extension fast enough to absorb the next bump. Too slow and your shocks pack down. Too fast and your vehicle or bike becomes a pogo stick that launches you off of obstacles.

Where are rebound adjusters located?

Most rebound adjusters are located at the bottom of the shaft on the eyelet. FOX’s X2 rebound adjusters are at the top of the shock on the piggyback bridge:

FOX makes a few types of rebound adjusters. What types of rebound adjustments do they make?

  • X2 – low-speed and high-speed dials
    • NOTE: New MY21 DHX2 and FLOAT X2 shocks have a high-speed rebound adjuster located at the bottom of the shaft on the eyelet;
  • Rebound knob at bottom of the shaft – low-speed dial
  • QS-R – low-speed 3-position switch

How do you describe rebound adjustments?

We talk about adjusting damping in two directions: decreasing and increasing. Remember the saying you probably learned as a kid: “Lefty loosey; righty tighty”? It applies to shocks, too.

FOX’s new three-position Quick Switch Rebound (QSR) with three distinct settings make it easy to dial in the correct rebound for different motorcycle riding situations: comfort on bumpy backroads, any-road balance of control and comfort, and a glued-to-the-asphalt feeling on smooth twisty roads.

Decreasing rebound damping is when you turn the adjustment knob counter-clockwise. We commonly also refer to this adjustment as “loosening”, “backing out”, “speeding up”, or “opening”. Think “lefty loosey”.

Increasing rebound damping is when you turn the adjustment knob clockwise. We commonly also refer to this adjustment as “tightening”, “bringing in”, “slowing down”, or “closing”. Think “righty tighty”.

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What does the shock do when I make an adjustment one way or the other?

When you decrease rebound damping by turning the adjustment knob counter-clockwise, you allow the shock to extend faster. It feels softer, more supple, and livelier.

When you increase rebound damping by turning the adjustment knob clockwise, you make the shock extend slower. It feels stiffer, more supportive, and more planted.

When and why would I decrease rebound damping?

As a general rule of thumb, if the terrain is rougher and you’re moving faster, you’ll want to loosen your rebound damping – allowing your shocks to rebound faster.

If your shocks are rebounding too slow, the repeated application of compression forces “pack down” in your shocks, which can cause a loss of traction and an uncomfortable ride. By loosening rebound damping, your shocks can extend fast enough to absorb the next impact or weight shift.

Here’s when you should consider decreasing rebound damping to speed your shocks up:

  • Ride feels generally harsh and you desire it to feel looser and more comfortable;
  • Vehicle or bike rides too low in the travel; your center of gravity is too low;
  • Small bumps and washboard-type terrain are harsh and uncomfortable;
  • Losing traction while cornering;
  • Losing traction in loose or slippery conditions;
  • Decreased spring rate, preload, or air pressure but want your shocks to rebound at the same speed as they previously were;
  • Vehicle or bike bounces off high-frequency, medium- to high-frequency impacts like whoops.

When and why would I increase rebound damping?

In general, if the terrain is smoother, you’ll want to tighten your rebound damping so your shocks will rebound slower, since you won’t need them to return as quickly as you do over rough terrain.

If your shocks are rebounding too fast, your shocks might act like a pogo stick and launch you off obstacles, which can also cause a loss of traction and an uncomfortable ride. By tightening rebound damping your shocks can extend slower to not launch you off obstacles.

Here’s when you should consider increasing rebound damping to slow your shocks down:

  • Front end bounces off of small- to medium-sized obstacles (like rocks);
  • Back end bucks off jumps and other bumps;
  • Chassis excessively rolls toward the outside edge while turning;
  • Chassis excessively squats during acceleration;
  • Chassis excessively dives during braking;
  • Bike excessively bobs up and down while pedaling;
  • Ride generally feels too soft and you desire it to feel tighter and more responsive;
  • Landing jumps or drops cause your vehicle or bike to become unsettled or bounce after you land.

Read “How To Use Low- And High-Speed Compression Adjusters”

Wait a minute. Why should I adjust rebound to stop chassis roll, acceleration squat, brake dive, and pedal bob? Isn’t that a compression issue?

Chances are it’s actually both. When your shock compresses, it will rebound soon after. Or, in the case of the first three scenarios, one group of shocks compresses whereas another rebounds.

For example: if you turn right in your vehicle, the chassis will have a tendency to roll to the left. When the chassis rolls to the left, the outside shocks and the inside shocks do different things:

  1. Your outside shocks compress, as the weight of the chassis rolls toward the outside. This is why increasing low-speed compression damping will help these outside shocks prevent the chassis from rolling toward the outside;
  2. But your inside shocks do the opposite: they extend. In order to control your chassis from rolling toward the outside as you turn right, you’ll want to increase rebound damping so that these inside shocks resist extending and prevent the chassis from rolling toward the outside.

Now think about this in terms of acceleration squat: the front shocks extend, but the back shocks compress. And the opposite is true of brake dive: the front shocks compress, but the back shocks extend. Increasing rebound damping will help to control chassis movements during acceleration and braking.

Lastly, pedal bob on a mountain bike involves the shock compressing and extending. So, if you feel like your mountain bike is bobbing too much while pedaling, don’t just increase your low-speed compression damping; also increase your rebound damping.


Like what you see? Check out all the FOX Academy videos for powered vehicles and mountain bikes here.