When it comes to optimizing your bike’s suspension system, achieving the correct rear shock sag is crucial for maintaining proper performance, comfort, and control. For riders using the Öhlins TTX22M Coil rear shock, a proper sag setup ensures that your bike responds effectively to bumps and uneven terrain. This guide provides a detailed, step-by-step process for setting up your rear shock sag, addressing common issues, and helping you customize your suspension for optimal performance.

Understanding the TTX22M Coil Rear Shock

The Öhlins TTX22M Coil is a high-performance rear shock designed for downhill and enduro mountain bikes. It features advanced damping technologies and a coil spring, providing superior control and responsiveness in rough terrain. The shock is known for its consistency, smoothness, and adjustability, which makes it ideal for riders who demand precise control during aggressive riding.

Setting up the sag on this rear shock is essential to ensure it performs at its best, providing the right balance between comfort and control.

Tools Required

• 8mm Allen wrench [paid link]
• Shock pump with pressure gauge
• Measuring tape or ruler
• Zip tie or velcro strap
• Torque wrench [paid link]
• Scales (optional, for measuring rider weight)

Step-by-Step Guide to Setting Rear Shock Sag

1. Prepare Your Bike

Before starting the sag setup process, ensure that your bike is on a stable surface, ideally in a workshop stand or similar setup. The bike should be in the same condition it will be used in, so make sure you’re wearing the gear (helmet, hydration pack, etc.) you usually ride with. This is crucial as the additional weight will affect the sag measurement.

2. Adjust the Spring Rate

The Öhlins TTX22M Coil shock uses a coil spring that needs to be correctly matched to your body weight and riding style. Before setting the sag, ensure that the coil spring rate is appropriate. Öhlins typically offers a range of spring options, and it’s important to choose one that allows for adequate compression without bottoming out too easily.

• If you are unsure about which spring rate to choose, consult the Öhlins sizing guide or speak to a suspension expert.

3. Install the Shock

Ensure that your rear shock is properly installed on the frame. Tighten the mounting bolts to the manufacturer’s recommended torque values. Misalignment or improper mounting can affect the shock’s performance and the accuracy of the sag measurement.

4. Set the Shock Pressure (if applicable)

If the TTX22M Coil features a separate air preload chamber, use a shock pump to set the recommended pressure. However, if you are working with a full coil-only system, skip this step as the preload is adjusted through the coil’s spring rate and tension.

5. Mark the Shock’s Stroke

With the bike in a stable position and your body weight on it, you’ll need to mark the shock’s stroke to measure how much it compresses. This can be done using a zip tie or velcro strap:

• Place the zip tie around the shock shaft just above the seal head.
• Make sure that the tie is snug enough to stay in place but not too tight to restrict movement.

6. Measure the Sag

To measure sag, you’ll need to sit on the bike in a riding position, making sure that you are applying your full body weight as you would while riding. The goal is to compress the shock enough to achieve a specific amount of sag, typically around 25-30% of the total shock stroke. For the TTX22M Coil, this typically equates to:

• 25% sag for more aggressive riding (enduro/downhill).
• 30% sag for trail riding or a more comfortable, balanced setup.

Once you’re in riding position, allow the shock to compress naturally under your weight. The zip tie will move down the shaft, and the distance from the original position will give you your sag measurement. Measure the distance that the zip tie has moved to calculate the percentage of sag.

7. Adjust the Preload

To adjust the sag to your desired setting, use the preload adjuster on the Öhlins TTX22M Coil rear shock. This adjuster allows you to change the tension of the coil spring, which in turn alters the amount of sag.

• If you have too much sag (the zip tie has moved too far), increase the preload by tightening the spring.
• If you have too little sag (the zip tie has moved too little), reduce the preload by loosening the spring.

It’s important to make small adjustments and recheck the sag after each change to ensure precision.

8. Final Check

After adjusting the preload and confirming that the sag is within the desired range, perform a final check by riding the bike. Test it on different terrains to ensure that the suspension feels responsive and balanced. The rear shock should neither bottom out nor be overly stiff. If necessary, fine-tune the preload further for optimal performance.

Troubleshooting Common Set-Up Issues

Incorrect Sag Measurement

• Problem: The sag is too high or too low, even after adjusting the preload.
• Solution: Double-check the coil spring rate. If the spring is too soft or too firm for your weight, it will be difficult to achieve the correct sag. Consider swapping the coil for a different rate if adjustments to preload do not provide the correct result.

Bottoming Out

• Problem: The shock bottoms out too easily, even with the correct sag.
• Solution: This could indicate that the spring rate is too light for your weight or that the damping adjustments are too soft. Try increasing the spring rate or adjusting the rebound and compression settings to prevent bottoming out.

Harsh Ride or Too Stiff

• Problem: The bike feels too harsh or stiff, even at the right sag.
• Solution: If the shock is too stiff, consider reducing the preload. Additionally, check if the compression damping is set too high. Reducing compression damping can make the shock more responsive to terrain, improving comfort.

Customization and Optimization for Better Performance

Adjusting Damping Settings

The Öhlins TTX22M Coil features separate low and high-speed compression and rebound adjustments. These settings allow you to fine-tune the shock for your riding style and terrain:

• Low-speed compression affects small bumps and pedaling efficiency.
• High-speed compression controls larger hits and impacts.
• Rebound damping affects how quickly the shock returns after compression.

For aggressive riders, consider using higher compression damping to prevent excessive diving on steep descents. Conversely, reduce rebound damping if you find the shock rebounds too quickly, causing the bike to feel unsettled.

Fine-Tuning for Terrain

Riders who regularly ride different terrains (e.g., smooth trails vs. rocky downhill courses) can optimize their shock setup by adjusting the compression and rebound damping. Experimenting with different settings allows for better responsiveness and control, giving you a more customized riding experience.

Comparing TTX22M Coil to Other Rear Shocks

While the Öhlins TTX22M Coil is widely regarded for its superior performance, it’s essential to understand how it compares to other rear shocks on the market. The TTX22M Coil is particularly suited for riders who prefer a coil spring setup over air shocks, as it offers more consistent performance and better handling of larger impacts. However, coil shocks tend to be heavier than air shocks and might not be the best choice for riders prioritizing weight savings for cross-country riding.

In comparison, air shocks like the RockShox Super Deluxe Coil or Fox Float X2 offer adjustability in terms of air pressure, making them lighter and more versatile for a wider range of riding styles. However, coil shocks like the TTX22M Coil provide superior performance and control in rougher terrains and for heavier riders.

Conclusion

Achieving the correct rear shock sag on the Öhlins TTX22M Coil is an essential step in optimizing your bike’s suspension system. By following this guide, you can set up your sag correctly, troubleshoot common issues, and make fine-tuned adjustments for the best possible performance. Whether you’re riding downhill, enduro, or trail, understanding how to adjust and maintain your TTX22M Coil will allow you to get the most out of your bike, enhancing both comfort and control in various conditions.