Garage Files: 5 Steps Of Suspension Setup
5 Steps Of Suspension Setup
Suspension setup is key to having the best experience possible on the type of terrain you are riding, but, unfortunately, we have seen quite a few riders on the trail who don’t have the proper setup. We assume they know that the dials, knobs and ports on their suspension do something, but, clearly, they don’t know enough about how to take advantage of these adjustments.
Without proper attention to your suspension setup, you will be battling against the terrain, which makes riding less safe. Nailing the right setting, on the other hand, will lead to confidence and control. This article explains how to get it right using the simple steps we follow. Take your time with this and do not rush. Grab your bike and follow along as we dive in!
Two primary adjustments are at play when you are setting suspension: how hard the spring is (low or high air pressure) and how that movement is controlled (the damping). With coil-sprung suspension, the firmness of the spring is dictated by the weight of the coil spring used. When you look at a coil, the first number is the weight (in pounds) needed to compress the spring by an inch (spring rate), and the second is the travel length of the spring (in inches). If you need a harder or softer spring, buy a new weight spring for a different rate.
Using a spring that’s too soft (or using too low an air pressure in an air shock) will result in suspension that dives too far into its travel and bottoms out more frequently. Pumping up a spring weight (too much air pressure) will result in a harsh ride that never utilizes a suitable amount of travel. The sensation kind of feels like a rough pogo stick.
Air-sprung suspension systems are becoming more common. The hardness (spring weight) is dictated by the air pressure in the chamber. If you need a harder or softer feel, adjust the pressure with a proper shock pump—not a floor pump for your tires but a dedicated suspension pump.
In this article we will explain our step-by-step approach to an air-suspension system, but we will also note when these techniques and concepts can be applied to a coil spring.
The way your system compresses and the way it rebounds back to its original position is controlled by the suspension damping. In short, damping is essentially fluid passing through small holes. Fluid moves at a more leisurely rate through small openings than it does through larger openings. When damping knobs/dials are being turned, the scope of the hole(s) changes the rate at which the fluid can flow through the hole.
How much control you have over your suspension damping will depend on the adjustment features the fork or shock comes with. Some only have a simple rebound damping adjustment. Other options (usually high-end models) generally have more tunability with high- and low-speed compression damping adjustments.
STEP 1: SETTING SAG
It’s important to always use sag as the starting point for suspension setup. Luckily, it is also one of the easiest steps in the process. So, what is it? Sag is the amount of suspension used when you place your body weight, including all riding gear, on your bike. Long before you touch any of your damping adjustments, you must first set your sag or spring rate.
On coil shocks or forks, the rider may need to swap out springs to achieve the correct amount of sag. With an air fork or shock, riders use a shock pump to achieve the correct sag setting. Whether air or coil (and depending on the brand recommendation), sag should generally be set between 25 and 30 percent at the shock and around 15 to 20 percent at the fork.
On a full-suspension bike, we start by twisting all the rebound and compression damping knobs (if applicable) to the minimum settings. It is best not to have the damping interfere with setting your sag.
Start by pushing the O-ring to the top of the stroke and then carefully sit on your bike. As mentioned before, make sure you are wearing all your gear. Slowly stand up on your bike, doing your best to avoid bouncing the suspension. Where the O-ring lands is the amount of sag currently set.
A shock is a bit more complex than a fork. Unlike what we see at the front, the shock stroke travel does not equal the amount of wheel travel. Instead, you will likely need to bust out a tape measure to confirm the stroke length of your shock (how much the cylinder is showing uncompressed). From there, divide your sag measurement by your stroke-length measurement.
For instance, on a rear shock with a 50mm stroke, running 12.5mm of sag, you would have 25-percent sag. If there is not enough sag to hit this mark, start letting air out in 5–10-psi increments with a shock pump. If there is too much sag, air will need to be added. Finding sag with a coil shock demands a somewhat different approach (changing the spring weight), but the basic methods are the same to measure for optimal sag.
STEP 2: SETTING REBOUND DAMPING
If your sag has yet to be properly set as we covered in Step 1, do not attempt to adjust your rebound. Rebound damping controls the speed at which your suspension re-extends after compression into the travel. If your rebound is set too fast, you’ll feel like you’re being sprung into the air. On the other hand, a setting that is too slow won’t allow the suspension to recover, causing it to pack up and feel stiff.
It’s important to note that rebound can be a personal preference. Some riders prefer a fast ramp-up; some prefer slow. A faster rebound (with less damping) is good for small, chattery bumps where the suspension needs to recover quickly to keep the tire planted to the ground. A slower rebound (with more damping) is going to cause the suspension to settle lower in its travel and offer a more predictable ride quality. Ideally, a rider will find a happy medium. Changes in air pressure, suspension design or riding style will determine how your rebound should be set.
Up next, we move over to the front fork and set up its sag. To measure sag on your fork, it’s best to stand up out of the saddle and have a friend help support you. If you don’t have a friend around at the moment, try riding on a flat surface and doing your best to place your weight on the fork without bouncing. Similar to step 1A, use the O-ring to help measure sag.
Let’s say the fork has 120mm of travel. Your sag should be between 18- and 24mm to achieve 15–20 percent. If you do not want to use a tape measure, there are some handy calculators that manufacturers have on their sites for a starting point based on your weight and height. As always, cross-check your sag measurements to see how accurate the calculators are. RockShox is the only company that has a sag percentage indicator on its stanchions. Why don’t other manufacturers do this? Because RockShox owns the patent. With your sag now properly set, you can move onto adjustments.
Rebound knobs are almost always indicated by the color red. The Fox Factory fork in our example offers both high- and low-speed rebound for further tuning your preferred adjustments.
One method is to start somewhere in the middle of the number of available clicks. To find the middle, turn the adjustment all the way in and count how many clicks are available by turning the dial all the way out. Then test the setting by rolling off a nearby curb and adjust according to your preference.
We also like the method of starting with the rebound set to the fastest setting with minimal damping. While standing next to your bike, push down on the bars and watch the fork quickly return back to your hands and bounce the front tire off the ground. Continue to add damping to your fork to slow down its rebound so that the front wheel no longer bounces off the ground. Your fork should always have a bit faster rebound than your shock to prevent you from being thrown over the handlebars.
The rebound knob on the shock is also typically red and will make the difference between you being thrown over the bars and keeping your rear tire firmly planted on the terrain. The shock’s rebound needs to be set quick enough so that the suspension has time to recover but not so fast that it pops the rear end of the bike around. For safety, we often start with a slower setting and decrease damping (adjusting it faster) if we feel the shock is sitting too low in its travel.
STEP 3: COMPRESSION DAMPING
Not all suspension forks or rear shocks on the market have adjustable compression damping, so this section may not apply to you. If your suspension does have adjustable compression damping, we recommend taking the time to get comfortable with how it operates before hitting the trails for the best performance possible.
Compression damping affects how your suspension compresses. You might also hear compression levers referred to as lockouts or pedal switches. If there is not enough compression damping, your suspension will flop around and go through its travel while you are pedaling, descending, and braking. By adding compression, you can firm up the suspension so it stays higher in its travel and offers a more supported ride. Keep in mind, however, there is a balance. This is a matter of personal preference and depends on your trail conditions and style of riding. Too much compression damping will prevent your suspension from absorbing impacts effectively.
PRESET COMPRESSION MODES
There are many shocks and forks that have built-in presets for compression damping. They will often have a pedaling platform mode with more compression damping and an open mode. The pedal platform setting has lots of compression damping. This will result in a firm ride (locked out) that resists moving under pedaling. Open mode means the least amount of compression damping, resulting in a plush ride for terrain but more pedal bob.
If you have suspension with properly adjustable compression (not the preset modes above), it’s worth getting to know how it works. A low-speed compression (LSC) dial will change how the suspension compresses at low speeds and when hit with low-amplitude forces.
The LSC is like your shock’s first line of defense against undesired compression. If you add a few clicks, this will help create more of a platform. On the other hand, if you reduce the amount of low-speed compression, this can help with small-bump sensitivity.
Dial-in low-speed compression until your suspension doesn’t bob excessively under pedaling. Some bob is fine (and often unavoidable), but it’s nice not to have your suspension bouncing around, robbing you of energy and control.
With LSC dialed in suitably, you’ll also find that your fork doesn’t dive or sink through its travel on steep descents, especially those where you’re breaking significantly.
High-speed compressions (HSC) occur when you hit a root, rock or come off of a drop. The shock has to compress fast to absorb the sudden impact. When this happens, the suspension fluid flows quickly and with enough force to blow past the low-speed circuit. Most shock designs allow the low-speed circuit to get out of the way by making an alternate flow path for the oil to go around it during HSC. Most forks will offer some form of HSC adjustment designed to firm up the fork, while LSC is usually only seen on mid-to high-end forks and is used to fine-tune their feel. Overall, by adding compression riders can firm up the suspension to stay higher in its travel and offer a more supported ride. Less compression offers a plusher or softer suspension feel. If your fork has both high- and low-speed compression adjusters, it’s important to tune the compression to suit your riding style and needs.
STEP 4: ADJUSTING SPRING PROGRESSION
Another popular way to adjust suspension settings is to add or remove air-volume spacers or tokens. A rider will add tokens to change how progressively a fork or shock responds. A more progressive suspension will better resist bottoming by becoming firmer towards the bottom of the stroke, whereas a linear rate will create an equal amount of force throughout the travel. Air forks and shocks are progressive by nature (unlike a typical spring/coil); however, some riders find the added resistance during bottom-out is helpful for harsh hits. On the other hand, lightweight riders or mellower ones who are having trouble reaching full travel, even with the correct amount of sag, may find it helpful to remove spacers in order to reach the bottom. Keep in mind that once a volume spacer is added or removed, you have to go back to setting sag again.
STEP 5: HACKS AND TIPS
Your bike will only perform as well as it’s set up to. If you have a new top-of-the-line bike with a poor setup, you will never even come close to experiencing the performance your bike is capable of. This is as true for high-end bikes as it is for inexpensive bikes. So, if you truly want to get the most out of your ride, it would be wise to spend quality time progressing through the steps above.
Average riders should have their forks and shocks serviced about once a year. This can depend on the condition of your ride, but if you race or ride frequently, your maintenance interval may be shorter.
#1. If for some reason your O-ring is missing, a small zip-tie snug enough against the stanchion to stay in place but loose enough to slide can be used instead. Carefully remove the zip-tie before riding to prevent scratching your stanchion.
#2. If you have ridden your bike at a dramatically different altitude, the lowers might have air built up inside. This bit of air will cause you to lose a bit of suppleness. Another zip-tie trick is using it to allow air to escape that can get trapped beneath your fork’s dust wipers. To remove this air, use a small zip-tie and delicately push it between the fork stanchion and the dust wiper seals. Insert the zip-tie just a few millimeters. You may hear a small wisp of air, but if you do not, there is no air trapped. Remove the zip-tie slowly and get back to setting your suspension up as before.
#3. It is important to keep suspension components clean. The stanchion and fork/shock seals will last longer if taken care of properly. Avoid using high-pressure air or water when cleaning around these areas, as they can force dirt or water in. When cleaning suspension, wipe around the seals and stanchion with a clean, microfiber rag.
This is bike nerd stuff, but it is very helpful to create a suspension log that notes your air pressure, rebound and compression settings, as well as your maintenance intervals. This can be invaluable when you want to return to a setting you liked or make sure you’re keeping up with regular service intervals. We hope this step-by-step setup guide helps get your suspension dialed for your next ride!