The suspension is an important part of your dirt bike because it allows you to control your dirt bike while riding over bumps and other obstacles in the track.
Also, your suspension must be set according to your weight and riding conditions to ensure optimum comfort and control while driving. Fortunately, the suspension is fully adjustable.
If you want to learn how to adjust suspension on a dirt bike such as how to properly set the sag and rebound and tune the compression, continue reading below!
Table of Contents
What to Prepare
Tuning your dirt bike suspension doesn’t really require any special tools. To be successful in the job, all you need are the following:
- Flathead screwdriver
- Tape measure
Steps to Adjust Suspension on a Dirt Bike
The suspension setup should be according to what kind of rider you are or your style of riding. In general, dirt bike suspension tuning also depends if you want more control or stability while riding.
Step 1: Measure the sag
There are two kinds of sag.
- The free or static sag is the measurement when the dirt bike sits on its own weight
- The rider sag is the measurement when the rider is on the dirt bike.
But how do you set the sag on a dirt bike?
1. Put your dirt bike on the ground again and bounce on your rear suspension while wearing all your riding gear such as a helmet, boots, etc.
2. Determine the free sag first by getting the measuring tape from the center of the rear wheel to a fixed point on the rear fender. You can ask someone to measure the two points again.
3. After, you can use the most common suspension calculator, which is subtracting your free sag and rider sag, to find out your race sag. Typically, your dirt bike should have around 95-110mm of race sag, but it really depends on your motorcycle’s manual.
You can also refer to this tuning chart for the general rule on how to set sag on a dirt bike.
|Engine Size||Ideal Rider Sag|
|50 to 65cc||70mm|
|85 to 100cc||80 to 90mm|
|125cc and up||95 to 100mm|
In addition, in terms of the percentage of travel, the ideal rider sag is roughly about 30% when you sit on the dirt bike.
Step 2: Adjust the sag
Depending on your preference, you can still adjust your sag measurement.
- If you want more stability, you can give your dirt bike more sag.
- However, if you want more control or better handling, you have to lessen the sag.
To adjust the sag to lower a dirt bike suspension or increase it, you need to follow the steps below:
1. Loosen the spring preload lockring to do the adjustment.
2. With your punch, place it against the collar or lock nut, and then strike its end with your hammer.
3. If you want to increase the sag of your dirt bike, move it counterclockwise. In contrast, if you want to reduce the sag, turn it clockwise.
Keep in mind that every rotation changes your sag by 2 mm or 3 mm. Once you have the new sag measurement, you need to measure your static sag again to ensure you have the accurate spring rate for your dirt bike.
Generally, your static sag should measure around 25 mm to 45 mm. If it ranges more than 45 mm, you need a softer spring, and if it’s less than 25 mm, your dirt bike requires a stiffer spring.
Step 3: Stiffen or soften the suspension
To ensure the spring on your dirt bike is in the proper range, you could stiffen or soften your suspension. Make sure you put the dirt bike on a stand to easily do the job.
1. Front Forks
If your front forks are too soft or too stiff, dirt bike front fork adjustment is a must. Just do a rebound adjustment and modify your compression clicker.
The adjustment tool you need here is the flathead screwdriver.
- Depending on your dirt bike model, the rebound clicker is often on the bottom and the compression clicker at the top. You need to look into your motorcycle manual to double-check.
- Use the screwdriver turn the clicker clockwise (toward the H) if you need stiff compression, which is ideal for soft terrain and hills.
Otherwise, turn your clicker counterclockwise (toward the S) if you prefer softer compression, which is perfect for small bumps and rough terrain.
- The rebound of your dirt bike determines how fast your shock recovers after a landing on the ground. After locating your rebound clicker on your fork or shock (typically labeled R at the top or bottom), use your flathead screw to adjust it.
- Twist it clockwise (toward the S) if you want a slow rebound, which usually works well when doing large jumps.
On the other hand, turn it counterclockwise if you need a faster rebound, allowing your dirt bike to recover quickly after being in contact with the ground.
Make sure you test-ride your dirt bike every one to two clicks to efficiently adjust your front suspension.
2. Rear Forks
In addition, if you’re looking into rear shock adjustment, keep in mind that the front suspension and rear suspension settings are not the same.
Check your manual to determine the location of the rebound clicker and compression clicker. The former could be at the bottom of the shock and the latter is typically at the top (but could be reversed depending on your dirt bike’s brand).
The rear suspension has two sets of compression adjustments: low-speed adjustment and high-speed adjustment.
If you want to improve how your dirt bike reacts to rocks and humps, adjust your low-speed clicker using your flathead screw. Wind it clockwise (toward the H symbol) if prefer harder compression and counter-clockwise (toward the S sign) for a softer compression.
Your high-speed clicker affects how your dirt bike deal with hard impacts such as when doing bug jumps. To adjust it, turn the clicker with your flathead screw clockwise to stiffen the rear suspension and counter counterclockwise for a softer compression.
The shock rebound works similarly to your front fork rebound clicker. Make sure you adjust it accordingly to properly control how your dirt bike reacts to impacts.
All in all, when doing front and rear compression adjustments, take note of the number of clicks so that you can easily pre-set your suspension depending on your preference. You can also watch this tutorial video if you need more guidance!
In summary, the setup guide for dirt bike suspension really depends on the rider’s weight and your style of riding.
The most important steps are to measure the sag and adjust it accordingly, as well as stiffen or soften your suspension to ensure proper control and stability.
Now that you know how to adjust suspension on a dirt bike, you’ll now have fun handling and controlling your dirt bike when riding!