The Bomber CR Trunnion [paid link] rear shock from Marzocchi is a top-tier choice for mountain bikers who demand performance and reliability. Regular preventative maintenance is essential to ensure optimal performance, longevity, and comfort. This guide will cover essential maintenance practices, troubleshooting common setup issues, customization tips, and more.

Tools Required

• 8mm Allen wrench [paid link]
• 2.5mm Allen wrench [paid link]
• Torque wrench [paid link]
• Shock pump
• Suspension fluid (as recommended by Marzocchi)
• Cleaning rag
• Small brush
• Grease (for mounting hardware)
• Silicone oil
• Replacement seals (if necessary)
• 4mm Allen wrench (for valve adjustments)

Routine Inspection and Cleaning

The first step in maintaining your Bomber CR Trunnion [paid link] rear shock is to ensure it is clean and free of dirt or debris. Cleaning the shock after every ride helps maintain its performance and prevents the buildup of harmful substances that can cause premature wear.

Step-by-step cleaning process:

1. Remove the shock from the bike frame using the appropriate tools.
2. Wipe down the shock body using a clean rag to remove dirt and grime.
3. Clean the stanchions gently using a small brush and soapy water. Avoid harsh chemicals that could degrade the shock’s seals or anodized finish.
4. Lubricate the shock seals with a small amount of silicone oil to keep them pliable and functioning smoothly. This is especially important if the shock is exposed to wet conditions or harsh terrain.
5. Inspect the shock for damage such as cracks in the body, worn seals, or leaks. If any damage is detected, replace the affected components immediately.

Suspension Fluid Maintenance

Changing the suspension fluid is a critical maintenance task that ensures the damping system functions as designed. Over time, suspension fluid can become contaminated with dirt, oil, or air bubbles, reducing its effectiveness.

Fluid change process:

1. Remove the shock from the bike and ensure it is in a safe, stable position to work on.
2. Remove the air canister from the shock body using the 8mm Allen wrench.
3. Drain old suspension fluid from the damper and air canister. You may need to carefully tilt or shake the shock to remove all the fluid.
4. Inspect the damper and canister for wear. Check for any visible damage that could compromise the shock’s function.
5. Refill with the recommended suspension fluid from Marzocchi. Be sure to follow the manufacturer’s instructions on fluid type and amount.
6. Reassemble the shock, ensuring all parts are securely torqued to specification.
7. Test the shock for proper damping function before reinstalling it on the bike.

Spring Tuning and Adjustments

Proper spring setup is crucial for the performance of the Bomber CR Trunnion rear shock. Adjusting the spring preload and rebound can significantly affect the ride quality and comfort, especially in different riding conditions.

Rebound Adjustment:

1. Locate the rebound knob at the bottom of the shock.
2. Turn the knob to adjust the rebound damping. Turn it clockwise for slower rebound (more damping) and counterclockwise for faster rebound (less damping).
3. Test the shock after making adjustments to ensure the rebound rate suits your riding style.

Air Spring Pressure Adjustment:

1. Attach a shock pump to the air valve on the shock.
2. Check the air pressure and adjust it according to your weight and riding style. It’s important to ensure that the shock is set to the recommended air pressure for your specific riding conditions.
3. Test the shock after each adjustment to make sure it feels balanced and responsive.

Preventative Seal Maintenance

Seals are a vital component of your Bomber CR Trunnion shock, protecting the internal parts from dirt, moisture, and wear. Regular maintenance and timely seal replacement can prevent issues such as air leaks and loss of performance.

Seal Care:

1. Inspect seals regularly for signs of wear or damage, including cracks, cuts, or bulges.
2. Lubricate seals with a silicone-based lubricant to prevent them from drying out or becoming too stiff.
3. Replace seals at regular intervals or if you notice air leaks or poor shock performance. Refer to Marzocchi’s recommendations for seal replacement intervals.
4. Ensure proper mounting when reinstalling the shock. Improper installation can lead to premature seal failure.

Troubleshooting Common Setup Issues

Even the best rear shocks can experience setup issues over time. Here are some common problems and their solutions:

Shock Bottoming Out:

• Cause: Insufficient air pressure, excessive sag, or worn-out damping.
• Solution: Check and adjust air pressure to the recommended level. If the shock still bottoms out, inspect the damper for any fluid leaks or damage and replace parts as necessary.

Poor Rebound Performance:

• Cause: Incorrect rebound setting, worn seals, or insufficient fluid.
• Solution: Adjust the rebound damping as described earlier. If the problem persists, check for fluid contamination or low fluid levels and perform a fluid change.

Leaking Air:

• Cause: Worn seals, faulty valve, or damaged shock body.
• Solution: Inspect the seals and valve for damage. Replace any worn or damaged components, ensuring they are correctly installed.

Customization and Performance Optimization

Customizing your Bomber CR Trunnion rear shock can enhance its performance, making it better suited to your specific riding style or conditions.

Adjusting for Weight and Riding Style:

• Spring Rate: Adjusting the spring rate can significantly affect how the shock performs. If you find that the shock is too soft or too stiff, adjusting the air pressure or swapping out the spring can help you find the perfect balance.
• Damping Settings: Fine-tuning the compression and rebound settings allows you to tailor the shock to your specific preferences, ensuring that it feels responsive and comfortable over various types of terrain.

Compatibility with Other Drivetrain Components

While the Bomber CR Trunnion rear shock does not directly affect drivetrain compatibility, it’s important to ensure the shock works in harmony with other suspension components, such as your front fork. Properly tuned front and rear suspension ensures a balanced ride, minimizing the chances of rear-end squatting or nosediving.

Conclusion

The Bomber CR Trunnion rear shock is a highly capable suspension component that can offer exceptional performance when maintained correctly. Regular inspection, fluid changes, seal care, and fine-tuning adjustments are essential to keeping it running smoothly. By following this guide, you can maximize the lifespan and performance of your rear shock, ensuring a smooth and responsive ride for every trail adventure.