Suspension set-up is crucial to getting the best performance from your mountain bike. Taking a few minutes to do it correctly will ensure that you’re getting the best ride out on the trail. You’ll need a shock pump and a tape measure. A scale is helpful for accurately determining your weight while wearing all of your riding gear including shoes, helmet, and any tools or a pack. Having another person to hold the bike also makes the process easier. Before starting, ensure that your tires are properly inflated. Set the red rebound dial to it’s mid-point. Do this by counting the total number of clicks in the dial, and setting to the middle. Set the compression damping to fully open by turning the blue knob on your fork all the way counter-clockwise, and the blue lever on your shock counter-clockwise to the open position. Use the Suspension Set-up Calculator to find your starting PSI. Remember that these settings are a starting point, and not rigid values. Thread the shock pump all the way onto the air valve and adjust the PSI to match your recommended starting point. Remove the pump and cycle the shock by firmly pushing down on the saddle to equalize the air pressure between the positive and negative chambers. With all of your riding gear on, stand over the bike and hold the front brake. Have a friend hold the bike up while you get on. Give the bike a bounce to activate at least 50% of the travel, and then settle into your normal seated riding position. Raise the shock o-ring all the way up, and the fork o-ring all the way down. Gently come off the bike forward. The distance between the o-ring and the seal is your sag. The ideal setting is 25-30% of the stroke. To ensure accuracy, find the ideal sag measurement for your bike on the Trek Suspension Calculator. Use a tape measure to find that distance. If the o-ring does not sit within 2 to 4 mm of the suggested measurement, use your shock pump to adjust the PSI. Add more air if the o-ring has traveled too far. Use the bleed valve to let air out if the o-ring did not move far enough. Repeat this procedure until you’ve achieved your desired sag measurement. Now it’s time to set your rebound. Rebound damping controls how quickly the shock bounces back after compressing. You can find a recommended starting point for rebound on the Trek Suspension Calculator. Start by turning the red dial on your shock or your fork fully clockwise to the fully closed position with the slowest rebound damping. From there, turn the red knob counterclockwise the recommended number of clicks. Remember that this is only a starting point. As you take your bike on the trails, pay attention to how the suspension reacts to bumps. If you feel a bucking sensation from your shock, or a pogo stick sensation from your fork, your rebound is too fast. You should slow it down by turning the red knob 1-3 clicks clockwise. If you feel like your fork or shock is packing down, or not fully recovering from successive hits, then you should speed up your rebound by turning the red knob 1-3 clicks counter clockwise. After a few rides, check your suspension settings by measuring the distance of the o-ring from the shock body or fork lowers. After a typical ride, the o-ring distance should match the specified stroke for your shock or the specified travel for your fork. Both of these measurements can be found in the shock and fork spec for your specific bike model on Trekbikes.com.