How To Adjust Your Dirt Bike Suspension – Simplest Guide

Bob and Derrick used to be a thorn in my biking gloves. Indeed, when everything works well, and man and machine are in sync, the ride feels telepathic. Taking the time to adjust your dirt bike suspension settings can dramatically affect the handling and performance of your bike over different terrain.

But taking other people’s time like Bob, Derrick and (I won’t mention his name for security reasons) do to me isn’t nice. Every time they come to me while the others are already on the trails, I feel like screaming! Until I taught them how to adjust their dirt bike suspension, they still pay so much money to fix their bikes.

The point of your bike’s suspension is that you have the power to adjust and transform your dirt bike from a bouncing Bob to a smooth breeze roller, depending on the terrain. You might be forced to go to a mechanic shop for this, and they will scoop off your wallet. This same method is how I taught Bob and Derrick, and they never disturbed anyone any longer since they can do it themselves.

Let’s get started.

What Do You Need?

Adjusting your dirt bikes suspension is one of the most natural hacks you can do to make your dirt bike riding memorable. It can also give you the worst experience if you do it wrong.

  • Get a screwdriver or shock wrench
  • Learn how suspension works
  • Get a friend to help
  • Adjust the suspension
  • Exercise much patience

Get A Screwdriver

So, (sorry if this sounds dumb, but this is how I mansplained things to Bob and Derrick) a screwdriver is that tool that has a single fork mouth. The screwdriver is what we will use throughout this adjustment exercise. We will use the shock wrench for where you don’t have screws. Are you following?

Learn How Suspension Works

Your bike is your bike when it can work with you. I mean that your bike must be able to carry your weight. That is why dirt bikes have suspension. The purpose of your dirt bike suspension is to absorb the shock when you’re going over hills and bumps at high speeds relative to your overall body weight.

When trying to adjust your dirt bike’s suspension, you must remember that each alteration you make will have effects positively and negatively. The changes you make your bike perform better over some terrain while performing worse on a different ground.

Suspension settings depend solely on your weight as the rider, and how aggressive your riding is. You should also consider the terrain, weather conditions, and if going on adventures, how much luggage you are carrying on the bike. And one thing is that not everyone weighs the same or has the same riding style. So Ricky Carmichael’s dirt bike suspension settings will not be the best setup for you. It’s a personal thing.

In learning about how it works, there are two essential parts you must find.

  • Spring
  • Damper

The spring holds the weight of the bike, and it absorbs impacts from the ground as you ride.

The damper, on the other hand, is used to slow down the compression of the spring as it squeezes together and returns to full length.

Without a damper, your bike will be bouncing around like a bubble.

Getting the balance between the spring and the damper is what will make your bike perform well under you.

Now here is how these structures work together:

  1. At the rear of your bike, there is usually an external spring on a single shock absorber mounted on the center.
  2. Damping is inside the structure of the unit. It most likely that your bike has an external reservoir to the damping system.
  3. At the front part of the bike, the springs hold themselves up internally within both legs that hold the front wheel.
  4. Many latest bike designs come with the separate fork system. This function means that manufacturers can split the spring and damper systems separately between the two legs. With this, one leg holds the spring, and the other leg handles the damping.
  5. If you ride an enduro dirt bike, you might find that most will have both springs and damping systems held together within each fork leg.
  6. Changing the spring or sag alters the height and the softness of the suspension. If you go down more, you will get a more steerable bike that’s less stable at speed, whereas, higher spring length predictably does the opposite.
  7. Preload refers to how short the spring gets at rest, without the rider onboard. Higher preload gives in harsher suspension because this means that the spring is short and will want to expand at any slight chance.
  8. Less preload gives a softer ride. If you make it too low or too high, your dirt bike will wobble like a cheap go-kart or an old lincoln.
  9. Damping is the result of compression and rebound.
  10. Compression controls how quickly the spring goes down while rebound controls how fast it expands or returns to the regular length.
  11. You should find the letters C and R on your shock and forks.

Manufacturers design and set up the suspensions on the bikes after many series of tests. However, we don’t weigh the same. Therefore, before adjusting your suspension, make sure to check your bike’s user manual.

So now let us adjust your dirt bike suspension.

How To Adjust Your Dirt Bike Suspension

Riding on soft terrain like a sandy trail usually needs more compression damping. Because the bumps will be bigger and spaced farther apart, more rebound damping will be required to minimize the impact.

Before you begin to adjust your suspension, here is a list of some things you must have in check. Courtesy of Gadnets:

  • Check the position of your clickers.
  • Mark the position with torque paint or a paint marker.
  • Adjust the tire pressure to suit your riding style and terrain.
  • Check your bike’s manual for the correct spring rate on your bike
  • Set your sag (we will go deeper into this in a jiffy).

Now you are ready. Let us adjust your bike suspension.

The Sag

The first thing you must make sure of is the sag setting. The sag refers to the length of how far the bike goes down under its weight and your weight as you sit on it. The sag is setting is the foundation for the setting or adjusting your bike’s suspension.

How to Set The Sag

This is easy. Follow these steps. I will explain them in a moment:

  • measure between two immobile points for an initial length reading
  • sit on your bike and make your friend measure the length of the same points
  • Calculate the sag
  • adjust the preload of the shock spring
  • measure the free sag
  • set the springs

Now, let us look into these steps one after another.

1. Measure Between Two Immobile Points

To do this, we recommend that you place your bike on a paddock stand or center stand.  It will take both wheels off the ground for a more accurate reading and convenience. Using a tape measure, check the length from any point on the swing arm somewhere close to the spindle to any point on the rear mudguard, or if you would, to the top of the number plate board. Use a gaffer tape or marker to mark the points you used because you will come back to those same points.

2. Sit on The Bike For Another Reading

Here, you want to find out how much stress you put on your bike whenever you ride on it. Therefore, you should put on all your rider kit, including your helmet and your boots or shinpads. Don’t sit on the bike while it is still on the paddock. Try to bounce up and down a few times on the seat. Haha, like a child. Yes, this action will help to remove any ‘stiction’ that can cause an error in the reading. So, here your friend or any passers-by can help you to measure between the same two points you have marked.

3. Calculate the Sag

The sag is the length with you onboard minus the length without you.

it boils down to this equation: No rider – Rider = Sag

Do you hate math? Lol. You have to subtract the second reading from the first. That will give the sag. Just like you calculate your change at the grocery store. Usually, you would get something around 100mm, but you still have to check your manual for the recommended figure.

4. Adjust the PreLoad on the Spring

If the sag is not at the required level and is more, you will need to adjust the preload of the shock spring. Release the preload collar lock bolt with a shock wrench or a screwdriver, and tighten the preload adjuster. As you do this, you compress the spring. You can do this with a hammer if the shock doesn’t have plastic. If it does, use a special tool from the OEM toolkit instead. Otherwise, Gadnets will not be responsible for broken parts.

However, if the sag is less than the recommended level, you need to slacken off the spring preload. Don’t get off the bike while you do this so that you can take measurements as you go until you reach the required sag.

5. Measure the Free Sag

Lastly, you measure the free sag. This is how you would determine whether the spring in your bike is right for your weight or not. Stand your dirt bike on level ground and measure the length between the same two points you have marked earlier. You would get it right if someone helped you to hold the bike so that it stands upright. Since you have the measurement of the length of these points while you sat on it, deduct that static sag from this new reading. This will show how much the machine sags under its weight. If the result falls between 20mm and 30mm, the spring is suitable for your weight. You can now retighten the preload collar.

If the sag is less than 20 to 30mm, the spring is likely too soft. If it’s more than 20-30mm though, then the spring is too hard. Then you might need a new spring. And we recommend the attention of a professional for that. There we have it for the rear. Let’s move forward, literally.

The Front Suspension

This is the more tedious part of this job, but stay with me, and you will school whoever says this is hard. Enduro bikes usually have preload-adjustable by turning a nut on the top of the fork. Even then, most of them have the new breed of air forks that have as many adjustments as possible. If you get stuck while trying to adjust the front suspension, always check your bike’s manual. Each bike has a specific process.

Front Springs

As a rule of thumb, the front sag and free sag on this part should be roughly the same as the figures you got while measuring the rear, if they are not the same, the bike will be unbalanced.

The point in case, if you find that the forks are not easy to adjust or that the front sag is way different from the rear, you might need the attention of a specialist. They will be able to identify whether you need to get preload spacers or you have to buy new springs to get the bike to behave correctly.

The Dampers

Now that we have fixed the springs on both sides, we need to look at the dampers. First again, we will go back to the rear.

Rear Damping

The damping on the rear of your dirt bike is split into two:

  • low-speed damping
  • high-speed damping

These are not how fast your bike runs. Instead, they are used to refer to how fast the shaft in the shock is moving.

When you ride on rocky trails, the shock will move up and down fast. Whereas, on sandy trails or softer terrains, the shock moves more slowly.

Low-Speed Damping

You can adjust the damping to low-speed compression adjustment if you turn the adjuster at the top of the shock absorber reservoir with a flat head screwdriver. Make sure to turn it by the required amount of clicks found in the manual.

High-Speed Damping

If you need to make your damping work for high-speed compression, you have to adjust it using a spanner, or a shock wrench on the outer nut at the top of the shock reservoir.

Whichever of the two options you have planned to achieve, make sure there is enough compression damping to ensure that you don’t smash through the shock’s movement when you hit bumps. You should also make sure that there is enough rebound damping so that the bike will not go around bouncing like an excited puppy. It should not even be so slow that the shock will not have returned by the time you hit the next bump.

You can find the rebound damping adjuster at the bottom of the shock absorber. You should adjust with a flat head screwdriver again.

Front Damping

On the front side, the settings are quite different. The compression and rebound damping adjusters are in different positions.

However, it is still straightforward to adjust. All you have to do is follow the R and C labels.

Adjust the rebound damping with a flat head screwdriver or an easy-turn adjuster at the top of the fork unit, and adjust the compression damping, in the same manner, using the adjuster at the bottom of the fork. You can find the C after you remove the rubber cap.

There you go! But don’t go yet. We have got some Tips and Tricks that will help you avoid destroying your machine. Quick, let’s run through:

Tip #1 – Slacken The Rebound?

If you have slackened off the rebound, what happens? The ride will feel significantly smooth because the wheel will move back very quickly, but if you take it too far, you will lose control. The more the damping, the harsher the ride.

Tip #2 – Tighten The Rebound?

If less rebound makes the ride nice and smooth, what will make me want to increase it and make it harsh? You see, having too little rebound reduces traction because the wheel will push back down in an uncontrolled way and that can lead to skipping.

Tip #3 – Too Much Damping?

Too much damping will make the shock far too harsh. It will give too much resistance to movement, and the full suspension travel will be useless.

Tip #4 – Too Little Damping?

If you make the damping too low, the bike will feel unstable and uncontrollable in your hands, allowing the suspension to travel through the full stroke.

Tip #5 – Rebound Damping

If the rebound damping is too high, the bike will sit too low, and it will return to the correct height rather slowly resulting. This slow-motion will cause poor traction. In harsh weather or irregular trails, you can lose balance and crash.

If the rebound, however, is too low, the bike feels nervous and unsettled. The suspension will jump around at every bump you hit.

Tip #6 – TroubleShooting

Here is a list of what you can do to solve several problems that occur when you are trying to adjust your dirt bike suspension by yourself. See the following table:

PROBLEMSCAUSESSOLUTION
If the suspension feels too hard, riding feels tense, and travel compression is not working.High compression damping or wrong spring rate or malfunctioning springs.1. Go to the rear; reduce the compression damping, and spring preload. Try to change the spring or spring rate.
2. On the front, reduce the compression damping and change the springs or spring rate.
If the suspension feels too soft, the bike is unstable and bottoms out as you ride.Low compression damping, low spring preload setting, malfunctioning springs or wrong spring rate.Increase the compression damping, increase spring preload or change spring or spring rate on both rear and front parts.
Bike loses traction and breaks away from the trail.Rebound too close, spring rate too high, steering going off.1. On the rear, push the rebound back and reduce the spring rate.
2. On the front, back off the rebound, raise the forks through the clamps to reduce the angle of steering.
The rear of the bike goes too low when on acceleration.High rear compression damping, low spring preload, wrong spring rate.Increase the rear compression damping, increase spring preload or spring rate.
Bike dives in cornersLow fork rebound, low oil level, or damping.Increase fork rebound, fork oil level or compression damping.
The bike turns too fast for me.Low rebound and compression decreased steering length.Increase in both rebound or compression, drop the forks through clamps to increase steering angle.
The rear of bike kicks around without staying inline.High spring rate, low rebound damping.Reduce rear spring rate or change spring, increase rebound damping.
Handlebar or bike head is shaking.Low for compression damping, malfunctioning springs.Increase fork compression damping, change springs / lower spring rate.
The bike bottoms out on the landing.Low compression damping and spring rate.1. On the rear, increase compression damping, increase spring rate.
2. Increase compression damping or oil level on the front part.

This straightforward guide is more than enough information to head you out to the garage and get busy with adjusting your dirt bike suspension. Remember to begin with the sag, and touch on the damping. You can then enjoy riding your dirt bike to your favorite trail for a test run. You will now have a more tame bike, just like keeping a tamed lion. Enjoy and stay safe. Never forget to share this free guide with your friends.