How to adjust your MTB’s suspension

To adjust the bike’s suspension setup, you should open all your damping settings. This means: The rebound – the red adjuster knob – needs to be turned counterclockwise as far as it will go. On a Simplon MTB, the adjustment range is illustrated with a plus and minus symbol. Then, it’s time to adjust the compression. Simply open the lever (adjuster knob) to its smallest setting. 

Good to know: If you have a bike with remote lockout, you should open the lever before starting the setup process. 

As a next step, you need to let the air out. Remove the valve cap and connect the shock pump. Always make sure that the pump sits straight on the valve – otherwise you might damage the screw thread. Now release all the air from the fork and the shocks. 

Slide your O-ring down to the seal. If there’s no rubber ring marker, you can alternatively use a loosely tightened cable tie. Firmly push down on the handlebars and compress the fork and the shocks as far as they will go. This can take a bit of force. 

Now, it’s time to use the shock pump again. Fill the suspension elements with approximately 50 PSI. This will make the fork and the shocks slowly uncompress again. Always use the manufacturer’s air pressure recommendations as a general guideline. 

When the elements are in an uncompressed state, you measure the distance between the seal and the O-ring. Jot down the measurements for the fork and the shocks and slide the O-ring all the way down to the rubber seal again. 

In step 3, you’ll set the SAG. For all those who aren’t familiar with the term (yet): SAG refers to the negative suspension travel. It denotes the part of the travel that is compressed by the weight of the rider. 

To determine the SAG, mount your bike and get into your usual riding position. Don’t shift your weight forward or backward too much. Be it a helper or a wall – you’ll need something to lean on for balance. 

Tip: If you’re frequently riding with a backpack, you should keep that in mind while adjusting the SAG and put it on – filled with what it usually holds. 

Now slide the O-ring (or cable tie) all the way up. When getting off the bike, be sure to not make any sudden movements or exert too much pressure on the bike. This might skew the measurements of the negative suspension travel. 

As a next step, you’ll determine the individual SAG value. It’s calculated by dividing the negative travel you’ve just measured by the total travel (e.g. 120 mm) of the bike and then multiplying it by 100. This gives you the SAG percentage. 

Simplon uses the following guiding values: 

• CC/Marathon: 20 - 25 %
• All Mountain: 25 - 30 %
• Enduro: 25 - 35 %
• Feeride / DH 30 - 40 %

To give you a basic idea: If you’re more of a marathon rider, the SAG should be at around 20 to 25 percent. The value is a bit lower because you need less travel. Freeriders, who exclusively ride on downhill trails and need more travel, generally also have a higher SAG. 

Simplon bikes have a scale on the stanchion that shows you the SAG percentage, which means you don’t have to calculate it yourself. To achieve the optimum setting, you need to tinker with it a little. By a process of elimination, you add a bit of air or release some of it again. You do that until you’ve reached the desired SAG value that you’ve calculated earlier. 

Final tip: Compress the chainstays of the bike again by stepping down on the back wheel with a bit of force and letting yourself fall onto the rear suspension. If the O-ring doesn’t slide off the stanchion when you do that – thumbs up!  

We’ll take a closer look at rebound damping in our fourth step. Just like compression damping, it relies on an oil circuit and controls the speed at which your suspension uncompresses after absorbing an impact. 

Rule of thumb: The higher the weight of the rider, the slower the rebound should be.  

How do you adjust the rebound? Shift your full bodyweight onto the fork and then quickly let go of the handlebars. The fork should rebound as quickly as possible but without the wheel bouncing off the ground. Repeat the process for the rear chainstays. The motto is: Feel your way to the right setting! 

You’re done with the general setup at this point. Now take your time to finetune the setting of your bike. Choose a short reference route: Ideally, it has a steep ascent, multiple sections with roots and rocks, small drops and a few jumps. 

Important: Never change more than one parameter at a time, e.g. don’t adjust rebound and compression at once. Because if you then test a setting, you’ll know exactly which effect it has. 

If you’ve got more questions about setting up your suspension, send us an e-mail at office@simplon.at – our Simplon experts always have the right tips and tricks for you! Or let your Simplon dealer on site  set up your bike for you!