Dirt bikes are a popular type of off-road vehicle used for racing, trail riding, and adventure riding. However, to get the most out of your dirt bike, it must be set up correctly for your riding style and body type.
One crucial aspect of dirt bike setup is the suspension, specifically, setting the sag correctly.
In this article, BSXInsight will provide a step-by-step guide on how to set sag on dirt bikes, including the tools and techniques required to get it just right.
What Does Setting the Sag on Dirt Bikes Mean?
Setting the sag on a dirt bike refers to adjusting the amount of suspension compression that occurs when the rider sits on the bike.
Sag is measured as the distance between the rear axle and a fixed point on the rear fender with the rider in a riding position.
This measurement is taken when the bike is static and without any rider weight and then again with the rider in a standing position on the bike.
The difference between the two measurements is the sag, and it’s expressed as a percentage of the bike’s total suspension travel.
Setting the sag correctly is important because it determines how much the suspension compresses under the weight of the rider.
If the sag is too little, the bike will feel stiff and harsh, and the suspension won’t be able to absorb bumps and impacts effectively.
Conversely, if the sag is too much, the bike will feel soft and wallowy, and the suspension won’t be able to keep the tires in contact with the ground effectively.
Setting the sag correctly ensures that the suspension is working in the correct range, providing the best handling, comfort, and control for the rider.
It’s a critical aspect of dirt bike setup, and every rider should learn how to do it properly to get the most out of their bike.
How To Set Sag On a Dirt Bike?
Measuring Your Bike’s Sag
The first step in setting your bike’s sag is measuring it. Follow these steps to measure your bike’s sag accurately:
- Put your dirt bike on a stand so the wheels are off the ground. This step is critical because it allows you to take accurate measurements without any external forces affecting the suspension.
- Measure from the rear axle up to a point where the fender and side panel meet. This measurement represents the unloaded sag, which is the distance between the rear axle and the fixed point on the bike when no weight is applied to the suspension.
- Remove your dirt bike from the stand and set it on level ground.
- Sit on the bike towards the front of the seat above the pegs in full gear. It’s important to wear all your gear, including your helmet, to ensure you get an accurate measurement of the rider’s sags.
- Have someone measure the compressed distance with you on the bike. The distance between the rear axle and the fixed point on the bike when you’re sitting on it is known as the rider sag.
- Check the amount of sag with the bike sitting on its own. This measurement is known as the static sag and represents the difference between the unloaded sag and the rider sag.
- Subtract the rider sag and static sag from the unloaded sag measurement to get the total sag. This measurement is expressed as a percentage of the bike’s total suspension travel.
Adjusting the Sag
Now that you have measured your bike’s sag, it’s time to adjust it to achieve the optimum sag setting for your riding style and body type. Follow these steps to adjust the sag on your dirt bike:
- Knock the top lock nut on the shock spring loose with a hammer and punch. You may need to use a lot of force, but be careful not to damage the threads.
- Turn the top lock nut counterclockwise with your hand to loosen it more. Be sure to turn it enough to allow for adjustment but not too much that it becomes too loose.
- Do some research to find your bike’s recommended sag range. This information can usually be found in your owner’s manual or by contacting your bike’s manufacturer.
- Loosen the bottom lock nut to increase the sag distance. Turn the bottom lock nut counterclockwise to increase the distance or clockwise to decrease it.
- Tighten the bottom lock nut to decrease the sag distance. Turn the bottom lock nut clockwise to decrease the distance or counterclockwise to increase it.
- Tighten the shock spring’s top lock nut again. Use your hand to turn the top lock nut clockwise until it is snug.
- Measure the rider sag and static sag again after making adjustments. Check to see if you have achieved the recommended sag range for your bike. If not, repeat the adjustment process until you have achieved the optimal sag setting.
- Remember to make small adjustments at a time and test-ride your bike after each adjustment to assess the difference. Setting the sag is essential to a dirt bike setup that ensures optimal performance, comfort, and safety while riding.
How Does the Sag Affect Dirt Bike Riding?
The sag is a critical component of your dirt bike’s setup that affects its handling, stability, and comfort while riding. The sag is the amount of compression on the rear shock when you sit on the bike.
Adjusting the sag properly ensures that your dirt bike is balanced and stable while you ride, which can significantly impact your performance and enjoyment. You need to understand two types of sag measurements: free sag (static sag) and total sag (rider sag).
What Is a Free Sag or Static Sag?
The free sag, also known as the static sag, is the amount of compression on the rear shock when the bike is stationary and unloaded.
To measure the free sag, lift your dirt bike off the ground using a stand and measure the distance between the rear axle and a fixed point on the bike.
The free sag should be around 10-30% of the total rear suspension travel, depending on your bike’s make and model.
What Is a Total Sag or Rider Sag?
The total sag, also known as the rider sag, is the amount of compression on the rear shock when you sit on the bike in your riding gear.
To measure the total sag, you need to sit on your dirt bike while someone measures the distance between the rear axle and the same fixed point on the bike that you measured for the free sag.
The rider sag should be around 25-35% of the total rear suspension travel, depending on your bike’s make and model.
How Does the Sag Affect Dirt Bike Riding?
The sag affects dirt bike riding in several ways:
- Handling: The sag affects how your dirt bike handles, particularly when cornering. Too much sag can cause your bike to wallow in corners, making it unstable and difficult to control. Conversely, too little sag can make your bike feel rigid and harsh, reducing your ability to absorb bumps and obstacles.
- Stability: Proper sag ensures that your dirt bike is balanced and stable while you ride, particularly when accelerating and braking. An improper sag can cause your bike to squat or stand up excessively, leading to instability and reduced control.
- Comfort: The sag affects the comfort of your ride. Too high sag can cause your bike to bounce excessively, leading to discomfort and fatigue. Too low sag can cause your bike to bottom out on bumps and obstacles, causing discomfort and potentially injuring your back.
What tools do I need to set the sag on my dirt bike?
You will need a measuring tape, a stand to lift your bike off the ground, a friend to assist with measuring the sag, and a shock spanner wrench to make adjustments to the shock.
How do I know if my sag is set correctly?
Your sag is set correctly if it falls within your bike’s recommended range and feels comfortable to you while riding.
You should be able to maintain control of your bike through bumps and corners without feeling like you are bouncing or getting thrown off balance.
Can I set the sag on my dirt bike by myself?
Yes, you can set the sag on your dirt bike by yourself with the help of a friend to take measurements.
It’s important to follow the correct steps and make small adjustments until you find the perfect setting for your riding style.
How often should I check and adjust my sag?
It’s a good idea to check and adjust your sag at the beginning of each riding season or if you make significant changes to your gear or riding style.
It’s also a good idea to check it periodically throughout the riding season to ensure that it hasn’t changed.
What happens if I don’t set my sag correctly?
If your sag is not set correctly, you may experience handling issues while riding, such as a loss of control, bouncing or bottoming out over bumps, or feeling like you’re getting thrown off balance.
Setting your sag correctly will help to improve your overall riding experience and make it easier to handle your bike.
Can I ride my dirt bike without setting the sag?
Yes, you can ride your dirt bike without setting the sag, but it may cause handling issues and make it more difficult to control your bike.
Setting the sag is an important step in ensuring that your bike is set up correctly for your riding style and will help to improve your overall riding experience.
In conclusion, setting the sag on your dirt bike is a crucial step in ensuring that your bike is set up correctly for your riding style.
By measuring your bike’s sag and making adjustments to the shock, you can improve your handling and overall riding experience.
Remember always to follow the correct steps and make small adjustments until you find the perfect setting for your riding style.
Checking and adjusting your sag periodically will also help to ensure that it hasn’t changed and that your bike is always set up correctly.
With the right tools and knowledge, you can easily set the sag on your dirt bike and enjoy a smoother, more controlled ride.