DIY HOME MECHANIC SERIES – AIR FORK SETUP

Shaun George BOTS Guides, D.I.Y, Mechanics, Tips & Tricks

MTBs are probably the most fun bikes to ride around trails or even in urban environments. If you’ve got an MTB with an air fork then you need to know how to set it up and take care of it.

Air forks especially, require a certain level of knowledge on how to set up and maintain. Setting up your suspension fork is absolutely crucial in order to get maximum comfort and control while riding off-road.

Air forks are popular on mid-range and high-end bikes because of their supreme feel and performance. That being said, they offer a lot more adjustability than normal coil forks. Get it wrong and you’ll be fighting a constant battle with your bike and the terrain. Get it right and you will enter a whole new world of control.

This brings about a perceived complexity in setting it up, which is not true. You can, in fact, do this set up at home on a regular basis.

Grab some tools and get cracking!

WHAT YOU’LL NEED

  • Zip ties
  • Shock pump
  • A friend
  • Measuring tape

Setting up your front fork is not hard. Take your time. Don’t do it in a rush in the car park before a ride.

WHAT YOU NEED TO KNOW

  • Setting your sag
  • Setting your rebound damping
  • Setting your compression damping
  • Setting progression

1. SETTING YOUR SAG

This is first thing you should to do with your suspension. Thankfully it’s also the easiest thing you’ll need to do. Sag is basically how much your bike settles into its suspension travel when you get on your bike and take your feet off the ground.

Suspension is designed to work best with between 25-35% sag. SInce most bikes these days come with a 100mm of travel, lets take that as anexample. With a 100mm of travel bike you want to aim to have 25mm-33mm of sagged travel when you sit on your bike.

  • You’ll need to lean against something, such as a wall.
  • Wind off all your rebound and compression damping (if you have it)  to the minimum settings.
  • Slide your suspension’s rubber O-ring (use the zip ties if you don’t have one) down to the seal.
  • Stand up on your pedals whilst leaning lightly against your friend.
  • Slowly get off the bike without compressing the fork any further.
  • How far the O-ring has moved in mm can be quickly worked out as a percentage of the fork’s overall travel.

Use your shock pump to add or decrease the amount of air in your fork. Remember, you need to attain a sag level of around 25-30%.

2. SETTING YOUR REBOUND DAMPING

Do not proceed to this step if you haven’t already set your sag. Rebound damping is what controls the speed at which your suspension re-extends after compressing i.e. after absorbing a hit.

Rebound dial
  • Dial off all your rebound damping to a minimum (usually indicated by a hare).
  • Ride off a curb, while standing up on the pedals, at slow to mid-paced speed. Your fork will probably bounce around like a trampoline and then settle.
  • Keep dialing on a couple of clicks of rebound until the trampoline effect is completely gone.

3. SETTING YOUR COMPRESSION DAMPING (IF APPLICABLE)

Not all bikes have compression damping adjustability, so ignore this if you don’t have it. Compression damping affects how your fork compresses.

Compression damping is more preferential and varies between riders. Some riders like an easy-moving supple suspension, other riders prefer super stable suspension that doesn’t move around too much.

Not enough compression damping will result in suspension that bobs around and dives through its travel while pedalling, descending and/or under braking (nose diving).

Too much compression damping will prevent your suspension from absorbing impacts effectively.

4. ADJUSTING PROGRESSION

Many suspension forks can be made to behave a certain way in the first half of their compression and differently in the latter half. You can have a supple, linear rate of action for the first third of your suspension’s travel and also have a firmer, travel action for the latter part of your suspension travel.

Volume spacers

Tweaking of the progression can be taken care of by volume spacers. Inserting volume spacers into your fork only affects how your suspension feels for the last part of its travel.

With volume spacers installed you can run lower air pressures in your suspension and/or less low-speed compression damping and have a supple freely-moving action to the early stages of your suspension’s travel. This at the same time will avoid your fork from diving through the latter stage of its travel.


Don’t neglect your suspension. It will deteriorate in condition drastically if you do. You can perform these basic services at home without the need of any specialty tools. You will need some brand and fork specific oil but apart from that you’re good to go.

How helpful was this article?

Click a star to rate.

Average rating 0 / 5. Vote count: 0

Shucks. We're sorry this post was not that useful

How can we improve this post for you?