Setting up your rear shock sag is a crucial step in ensuring optimal performance and comfort on your Öhlins TTX22M Trunnion [paid link] rear shock. Proper sag adjustment allows the shock to function within its ideal travel range, improving traction, stability, and overall ride quality. In this guide, we will cover the steps involved in setting the sag for the TTX22M Trunnion [paid link], troubleshooting common setup issues, and providing tips for fine-tuning the suspension for different riding conditions.

Tools Required

• Shock pump
• Ruler or sag measurement tool
• Marker or tape (optional)
• Torque wrench [paid link] (for final tightening)
• Allen wrenches [paid link] (if needed for adjustments)

Understanding the TTX22M Trunnion Shock

The Öhlins TTX22M Trunnion rear shock is designed for performance-oriented mountain bikes. Featuring a trunnion mount, this shock offers improved stiffness, durability, and adjustability compared to traditional eyelet-mounted shocks. The TTX22M utilizes Öhlins’ renowned Twin Tube technology, which provides exceptional sensitivity to small bumps and maintains damping performance under high loads.

Before diving into the sag setup process, it’s important to understand the key features of the shock that will impact the sag adjustment:

• Trunnion Mounting: The trunnion mount allows for a more compact shock design, providing better frame compatibility and reducing the overall length of the shock.
• Adjustability: The TTX22M offers high- and low-speed compression, rebound, and preload adjustments, which help in customizing the shock’s behavior for your specific riding style and terrain.
• Air Pressure: The air spring pressure plays a critical role in setting the correct sag, as it determines how the shock responds to rider weight and terrain.

Setting Up Rear Shock Sag

Step 1: Measure Rider Weight and Select Initial Pressure

The first step in setting up the sag for the TTX22M Trunnion is to ensure that the shock’s air spring is correctly set to accommodate your weight. Öhlins provides a recommended air pressure range based on rider weight, which can serve as a starting point.

1. Consult the TTX22M user manual or Öhlins’ online resources for the recommended pressure for your weight.
2. Using the shock pump, inflate the shock to the recommended starting pressure.

Note: Keep in mind that the actual sag will also depend on your riding style, terrain, and personal preference. The recommended starting pressure is just that – a starting point.

Step 2: Prepare for Sag Measurement

To measure sag, you need to understand the concept of “sag” in suspension. Sag refers to the amount the shock compresses under the rider’s weight, typically expressed as a percentage of the total travel. The recommended sag for most riders falls between 25-30% of the total shock travel.

1. Mount your bike on a flat surface.
2. Ensure that the shock is in the “open” or “active” mode if applicable (check your shock’s settings).
3. Remove any load from the shock (i.e., not sitting on the bike).
4. Attach the sag measurement tool to the shock or use a ruler to measure from a fixed point on the shock body (usually the shock’s air can) to a reference point on the frame or shock mount.

Step 3: Measure Static Sag

1. Sit on the bike in your normal riding position, ensuring that you are in full gear (helmet, shoes, etc.).
2. With the bike in a stable position, measure the distance that the shock compresses when your body weight is applied. This is your static sag.
3. Compare the measured sag with the recommended sag range (usually 25-30% of the shock’s travel).

Step 4: Adjust Air Pressure for Correct Sag

If the sag measurement is outside the recommended range, you will need to adjust the air pressure in the shock to achieve the desired sag:

• Increase air pressure: If the sag is less than the desired range (i.e., less travel), add air to the shock.
• Decrease air pressure: If the sag exceeds the desired range (i.e., too much travel), release some air from the shock.

After making air pressure adjustments, re-measure the sag to ensure that it falls within the optimal range.

Step 5: Fine-Tune Rebound and Compression Settings

Once you’ve achieved the correct sag, it’s time to fine-tune the rebound and compression settings for your riding style and conditions.

• Rebound: Adjust the rebound damping to control how quickly the shock returns after compression. Start with a medium setting and adjust depending on how fast or slow you want the shock to rebound.
• Compression: Set the high- and low-speed compression settings based on the type of terrain you typically ride. Lower compression settings offer a more plush feel, while higher settings improve pedaling efficiency and stability on rough terrain.

Troubleshooting Common Setup Issues

Even after correctly setting up the sag, you may encounter some issues that require further adjustments:

• Too much sag: If you’re bottoming out frequently or feel the shock is too soft, try increasing the air pressure in the shock. Also, check the rebound and compression settings to ensure they are correctly tuned.
• Not enough sag: If the ride feels too harsh or the shock doesn’t compress enough, try reducing the air pressure. This may also be a sign that your spring rate is too high for your body weight.
• Unstable or bouncy ride: This could indicate that the compression settings are too low, causing the shock to react too quickly to small bumps. Increase the compression damping and test again.
• Odd sounds or performance issues: If you hear strange noises or experience unusual performance, it could be a sign that the shock requires service. Check the air can and seals for damage, and consider having the shock serviced by an expert if needed.

Customization and Optimization for Better Performance

For riders looking to optimize the TTX22M Trunnion for specific needs, here are a few customization tips:

• Adjusting for specific riding conditions: If you mostly ride aggressive downhill or enduro trails, consider increasing the high-speed compression to reduce excessive suspension movement. For cross-country or trail riding, you may prefer a softer, more responsive feel by decreasing the compression settings.
• Weight tuning: Riders who frequently change their gear load (e.g., carrying extra gear or tools) may need to adjust air pressure for different riding conditions to ensure consistent sag.
• Fine-tuning the damping: Adjust the rebound and compression to match the terrain you ride most often. For rocky or technical trails, stiffer compression settings and a slower rebound may be beneficial for maintaining control.

Comparison with Other Models

The Öhlins TTX22M Trunnion rear shock is part of Öhlins’ premium shock lineup, designed for riders who demand the highest level of performance. In comparison to other rear shocks on the market, the TTX22M offers superior durability and a refined suspension feel due to its Twin Tube design and extensive adjustability. While other shocks may offer similar features, the TTX22M stands out due to its ability to offer precise tuning for both compression and rebound, ensuring optimal performance across a wide range of riding styles.

Additionally, its trunnion mount provides a more rigid and stable mounting system than traditional eyelet mounts, reducing flex and improving overall suspension response. This makes it an excellent choice for riders seeking precision and reliability on demanding trails.

Compatibility with Other Drivetrain Components

The Öhlins TTX22M Trunnion is compatible with a wide range of modern mountain bike frames that utilize the trunnion mount standard. However, it is important to ensure that the shock’s dimensions match the specifications of your bike frame. Double-check the shock length, stroke, and mounting hardware to ensure compatibility before purchase.

In terms of drivetrain compatibility, the TTX22M works seamlessly with most modern drivetrains, including both SRAM and Shimano systems. However, frame clearance and shock configuration should always be verified to ensure optimal fit and performance.