Mastering Rear Suspension Tuning for New Mountain Bikers

As a professional mountain bike coach at Summit Bike Academy, I’ve seen countless riders struggle with rear suspension setup. Getting it dialed in can transform your ride, making your bike feel more stable, responsive, and confidence-inspiring. Let’s break down the key variables you can control and how each one affects your ride.

1. Sag (Spring Preload)

Sag is how much your suspension compresses under your body weight when you’re sitting still on the bike. It’s measured as a percentage of the shock’s total travel, typically between 25-30% for most trail riders.

• Too little sag (under 20%)

• Your bike will feel stiff and harsh over bumps.

• Traction will be reduced, especially on loose or rough terrain.

• It may feel twitchy and less forgiving, making technical trails more difficult.

• Too much sag (over 35%)

• Your suspension will feel too soft and bottom out on bigger hits.

• Climbing becomes inefficient as your pedaling energy is absorbed by the suspension.

• The bike may feel sluggish and unresponsive.

Pro Tip: Start by adjusting the air pressure in your shock or coil preload to achieve the correct sag for your weight and riding style.

2. Rebound Damping

Rebound controls how quickly your suspension returns to its original position after compressing. Too fast or too slow, and you’ll lose control and efficiency.

• Too fast (little damping)

• Your bike will feel bouncy, like a pogo stick.

• The rear wheel may skip over bumps instead of staying planted.

• It’s harder to maintain control on fast, rough descents.

• Too slow (too much damping)

• Your suspension will feel “dead” and won’t recover in time for the next hit.

• On rough terrain, the shock can “pack down,” staying compressed and reducing travel.

• The bike may feel sluggish and sap your energy.

Pro Tip: Start with your rebound adjustment in the middle of its range and fine-tune based on feel. A good balance is when the bike feels controlled but recovers fast enough for repeated hits.

3. Compression Damping

Compression damping controls how your suspension resists compression from bumps or rider inputs. There are usually two types: low-speed compression (LSC) and high-speed compression (HSC).

• Low-Speed Compression (LSC)

• Affects suspension movement during pedaling, braking, or cornering.

• Too little LSC: The bike feels squishy and wallows under pedaling or hard cornering.

• Too much LSC: The bike feels harsh over small bumps and lacks traction.

• High-Speed Compression (HSC)

• Affects suspension movement on big hits or fast impacts.

• Too little HSC: The shock may bottom out on big drops or jumps.

• Too much HSC: The bike feels harsh on rough terrain, transferring impacts to your body.

Pro Tip: Start with the manufacturer’s recommended settings and adjust one click at a time. For beginners, focus more on low-speed compression unless you’re tackling bigger jumps and drops.

4. Bottom-Out Resistance (Progression)

Many modern shocks have an adjustable air volume (or you can add spacers) to control how much the suspension ramps up at the end of its travel.

• Too little progression (linear feel)

• You’ll bottom out easily on hard hits or big drops.

• The bike may feel less supportive when landing jumps.

• Too much progression

• Your suspension will feel harsh toward the end of its travel.

• It’s harder to use all your travel, even on rough terrain.

Pro Tip: Riders who enjoy jumps or technical trails often prefer more progression, while trail riders may opt for a more linear feel.

5. Pedal Platform (Climb Switch)

Many shocks have a climb switch or pedal platform feature that increases compression damping for climbing efficiency.

• Switch Off: Best for descending or technical trails, as it allows the shock to remain active for bumps.

• Switch On: Ideal for smoother climbs, where you want a more efficient pedaling platform.

Pro Tip: Use the climb switch for long, steady climbs but remember to turn it off before descending to regain full suspension performance.

How to Fine-Tune Your Suspension

1. Start with the manufacturer’s recommendations for sag, rebound, and compression. These are usually found in the bike or shock manual.

2. Test on familiar trails: Ride a loop you know well, with varied terrain (climbs, descents, technical features).

3. Adjust one variable at a time: Make small changes, ride the same section, and take notes on how the bike feels.

4. Find your sweet spot: You’ll know it when the bike feels balanced, predictable, and confidence-inspiring.

Common Mistakes to Avoid

• Skipping sag setup: If your sag is off, everything else will be off, too.

• Over-adjusting: Avoid extreme settings; often, small tweaks make the biggest difference.

• Ignoring tire pressure: Suspension and tire pressure work together. Too much air in your tires can make even the best suspension feel harsh.

Dialing in your rear suspension may seem intimidating, but with a methodical approach, you’ll feel a huge improvement in control, comfort, and fun on the trail. At Summit Bike Academy, we help riders of all levels find their perfect setup. If you’re ready to take your riding to the next level, come ride with us!

Ride smart, ride smooth, ride Summit.