For maximum control and comfort while riding off-road, setting up the suspension fork and shock is extremely important. Get the suspension setup wrong and you will find yourself fighting a constant battle with your mountain bike and terrain. Get the setup right and you will tap into a new world of luxury while riding on unforgiving terrain.
While setting up the mountain bike suspension fork might seem overly complicated, getting the basics right is very simple. In this guide, we will focus on showing you how to dial in your bike’s suspension.
How to Get the Mountain Bike Suspension Set Up Right
1. Set Your Bike’s Sag
For your type of suspension to perform optimally, it has to respond to every contour you come across on the bikepacking trail. When your MTB wheels hit an object, the fork and shock should compress, absorbing the energy generated by the impact.
The energy is then released when the suspension extends out again. In addition to absorbing impacts, the suspension setup also extends to fill holes and keep the mountain bike tires on the ground – this helps improve traction.
To let the suspension extend and compress as needed, it is preloaded with the rider’s weight. The amount of preload needed for a certain mountain bike is known as sag. Sag is the amount the suspension setup compresses into its travel when the rider sits on the hardtail mountain bike.
If your bike has too little sag, it will lack grip as it won’t extend into compressions. If the bike has excess grip, it will wallow and respond poorly to any repeated impacts.
Setting Up the Rear Shock Sag
Before you start, put your rear shock in the fully-open mode. If you have the low-speed compression adjust, be sure to wind it fully in the [-] direction. Next, support the bike on level ground and then climb on. Once on the bike, follow these steps:
Note: It will help to have an assistant
- Firmly, bounce up and down on your bike to charge your negative spring and to free the travel.
- Assume the normal sitting position and then after allowing your bicycle to settle for a minimum of 5 seconds, have an assistant push the O-ring on your shock stanchion down (or up) to your bike’s wiper seal.
- Carefully, rock your body weight forward and then dismount from your bicycle without disturbing the bike’s O-ring.
- In millimeters, measure the distance that your O-ring has been moved up from the bike’s O-ring.
- Divide the obtained value by the bike’s total shock stroke (this value will be available in the bike manual). Multiply this fraction with 100 to get the percentage sag. For example, 15 mm/ 50 mm x 100 will give you 30%.
- To get a perfect sag, remove or add air to your air-spring as necessary and then repeat.
Most bikes will come with a suggested sag setting from the manufacturer. If your bike doesn’t have, a base of 30% will be ideal. If you need less sag, add air to your shock. If you need more sag, reduce the air pressure. When adding air, use 10 psi increments and every time, repeat the process described above to achieve an ideal sag.
Setting the Fork Sag
Once you are done with the rear shock suspension set up, move on to your suspension fork. First, ensure that the suspension damping is 100% open and then adjust the air spring pressure to your manufacturer’s recommendation. Have an assistant support your mountain bike for big guys as you climb.
- Firmly, bounce up and down on the bike. This will charge the negative spring and also free up your seals.
- Assume the standing attack position and then allow the downhill mountain bike to rest for about 5 seconds.
- Have your assistant slide the O-ring on your fork’s stanchion down to the wiper seal.
- Rock your weight back carefully and then dismount the bike, without causing any disturbance to your O-ring.
- Measure the distance that your O-ring has been pushed from your bike’s wiper seal in millimeters. Divide the value by total travel (this could be 160 mm) and then multiply by 100 to get a percentage sag.
- Remove or add air to your spring as needed and repeat. This will help you get an ideal sag.
If your bike has a manufacturer’s recommendation for the fork sag, use it. If none is available, use 20% during the suspension set up.
Go on a short biking trip – this should be on a local trail with features you often experience when mountain biking. The ideal trail should have rocks, jumps, drops, berms, G-outs, etc.
Choose a trail where you expect to use full suspension travel. Before you can start tuning, ensure that all external compression and rebound are already set to your manufacturer’s recommended settings. This should put the settings in an ideal range for your body weight.
2. Optimizing the Air-Spring Rate
While 20% sag in your fork and 30% in your rear shock is an ideal base setting, it may not be optimal for your suspension design and riding style. Spring rate – this is the force you need to compress your spring – will be a balance between small bump sensitivity and big-hit support. The best settings for you will depend on the trails you ride and riding style.
After a few runs on your chosen trail, push the shock and fork O-rings down to the wiper seal and ride the trail again, take note of how big drops and impacts feel. Is the bike bottoming out harshly? Do the small bumps feel harsh? Are you achieving full travel in the expected trail zones?
If the rear part of your bike feels stuck to the ground and bottoms out easily, the shock spring rate is very low. Use your shock pump to add pressure to your rear shock, approximately 10 psi at a time, and then ride your bike on the trail again. Stop adding air when your bike feels good. Note down the optimized pressure.
If the bike’s rear feels harsh over small bumps and fails to give full travel in desired areas, the shock spring rate is extremely high. Remove air pressure, 10 psi at a time, and then ride again. When the bike feels good, note the optimized pressure.
If the suspension fork dives when riding steep hills or when you pull your MTB brakes, the spring rate is low. Add pressure to the fork, five psi at a time, and test it again. When you achieve an ideal pressure, note it down.
If the suspension fork doesn’t have grip and feels harsh on small bumps, the fork air spring rate is extremely high. Remove pressure, five psi at a time, and test again. Note down the ideal pressure when you achieve it.
3. Spring Rate Progression Rate
The next step on suspension set up will require considering how powerful you are and how challenging your bikepacking trips are. If you are a strong rider and you feel like the rear suspension bottoms out frequently, the fork runs low in its travel when negotiating corners, or under hard braking, you may need to adjust the bike’s spring rate progressivity.
For a more progressive spring rate, you will need to add volume spacers. To reduce the progressive spring rate, you will need to remove the spacers. More volume spacers make the final part of your suspension stroke much firmer, requiring additional force to bottom out.
If your current suspension setup is bottoming out frequently despite using an ideal air-spring pressure, add 1 to 2 volume reducers to reduce the air volume in your shock or fork air-reducing chamber. If you feel like every time you sit on your MTB saddle you struggle to achieve full travel in parts of the trail where you expect this to happen, increase the air volume by removing 1 to 2 volume reducers in the shock or fork air spring chamber.
4. Adjust the Rebound and Damping
Rebound damping helps control the speed at which your compressed suspension extends after an impact. If your bike’s rebound damping is too low (-), your suspension will extend too fast, making it feel bouncy and out of control. If your rebound damping is too high (+), your suspension won’t recover fast enough to repeated impacts – it will perform poorly, constantly sinking lower into its travel.
Setting the Rebound Damping on the Shock
- Add maximum rebound damping (+) on your shock.
- Select a small drop that you can ride off slowly and put your focus on how your rear suspension springs back after every impact.
- Repeat the test, every time reducing your rebound damping by a single click (-), and seeing if the shock recovers faster.
- Stop when the shock recovers fast enough to overshoot a little bit. This should be an ideal base setting.
- Now, repeat a whole section of your trail with this setting. Experiment 2 more times with 2 clicks either side and see which feels more controlled and offers an ideal grip.
Setting the Rebound Damping on the Fork
- Start the process with your rebound completely closed (+). Stand next to your bike, holding the MTB handlebars and compress your fork with your body weight. Release the fork and allow it to bounce back.
- Adjust the rebound until your fork rebounds as fast as needed without causing the front bike wheel to jump such that it clears the ground.
- Once you set the base section, repeat a whole section of the trail at the setting. Experiment at least 2 times with two clicks either side and see which offers a good grip and ideal control.
5. Check for Balance
When it comes to damping and rebound, in all cases, balanced suspension setup is needed to ensure optimal performance. As a final check, look for level ground and then ride your bike very slowly across it.
From the attack position, bounce up and down as hard as possible. Your bike should feel supportive and its rebound speed should feel balanced for both the rear and front. If the bike feels unbalanced, determine where the imbalance is coming from, and then make the necessary adjustments.
Q: How Do You Set Up A Suspension?
When setting up a suspension, you will need to focus on:
- Setting the rear shock and fork sag
- Optimizing your bike’s air-spring rate
- Adjusting the spring rate progression
- Ensuring that the rebound and damping is perfect for your type of riding
- Ensuring that a balance exists between your rebound and damping.
In this detailed guide, we have all the details you need to succeed in all the steps mentioned above.
Q: How Do You Set Up A Full Suspension Bike?
Full suspension bikes have rear shock and front fork suspensions. Setting up the suspension for these bikes will involve paying special attention to the rear shock and front fork. Each may need special steps to set up – we have outlined these steps in this guide.
Q: What is Suspension Tuning?
Suspension tuning involves making sure that all parts of your suspension are working correctly. Anytime your bike suspension is actively working, there is an intricate dance going on between all of the suspension components to achieve one goal – keep the tires in contact with the road and to keep you comfortable. Suspension tuning helps eliminate unwanted handling characteristics while riding your bike, making the entire experience smooth on rough patches and when cornering.
Globo Surf Overview
Good suspension setup can make a good bike feel great. However, a poor setup can make any great bike feel terrible. The key to enjoying off-road bike rides is to ensure that your bike has a properly tuned suspension.
Spending several hours tweaking the suspension system on your bike can help transform your riding enjoyment. In this guide, we have detailed the exact steps you will need to follow in the suspension set up process. As long as you have an assistant at home, you may not need to take your bike to a repair shop.