The Bomber Air Trunnion [paid link] Rear Shock by Marzocchi is known for its durable design and high-performance characteristics. As a crucial component for maintaining proper bike suspension, this shock demands attention to detail during installation, adjustment, maintenance, and troubleshooting. This guide will cover everything you need to know to keep your Marzocchi Bomber Air Trunnion [paid link] in top working condition.

Tools Required

• 5mm Allen wrench [paid link]
• 8mm Allen wrench [paid link]
• Torque wrench [paid link]
• Suspension fluid (specific to Marzocchi’s requirements)
• Rags or cleaning towels
• Shock pump
• Needle for air valve maintenance
• 10mm spanner wrench
• Marzocchi-specific oil bath kit (if applicable)
• Grease (light, suspension-safe grease)
• Clean, soft brushes for cleaning

Installation of the Bomber Air Trunnion Rear Shock

Proper installation of the Bomber Air [paid link] Trunnion is critical for both performance and safety. Below is the step-by-step guide for installing your shock:

1. Prepare the Bike and Shock Mounts: Before installation, clean both the bike’s rear triangle and the Bomber Air [paid link] Trunnion shock to remove any dirt or debris. This ensures a smooth fit and prevents contamination of internal components.
2. Align the Shock: Position the shock in its designated trunnion mount. Make sure the trunnion mount aligns with the eyelet of the shock without any force applied. This step is critical, as misalignment can lead to binding and premature wear.
3. Insert the Mounting Hardware: Insert the mounting bolts into the trunnion mounts. Tighten them gently by hand to ensure they sit in place properly.
4. Torque to Specifications: Using a torque wrench [paid link], tighten the bolts to Marzocchi’s specified torque settings. For most models, this is usually between 8–10 Nm. Always follow the manufacturer’s specific torque recommendations to avoid over-tightening or under-tightening.
5. Check for Smooth Movement: After installation, check the rear shock’s movement. Compress and rebound the shock a few times by hand to ensure it moves smoothly without resistance.

Adjusting the Bomber Air Trunnion Rear Shock

Adjustment of the Bomber Air Trunnion ensures that the rear suspension is tuned to your riding style and terrain. The shock features an air spring, compression, and rebound adjustments.

1. Preload Adjustment: The preload setting determines the initial sag of the shock. Use a shock pump to adjust the air pressure to the recommended value based on your rider weight. Typical starting pressures are between 190–230 psi, but adjust accordingly.
2. Rebound Adjustment: The rebound dial located at the base of the shock allows you to fine-tune how quickly the shock extends after compression. For smoother terrain, set it to a faster rebound. For rougher trails, adjust for slower rebound to enhance control.
3. Compression Adjustment: Use the compression knob to modify how the shock responds to hits and impacts. Increasing the compression dampens the shock’s response, ideal for aggressive riding or large impacts. Reducing the compression allows for more sensitivity, which is beneficial on smoother surfaces.
4. Fine-Tuning: After adjusting, test the bike by riding it on the terrain you typically cover. Fine-tune the settings until you achieve the desired feel and performance.

Maintenance of the Bomber Air Trunnion Rear Shock

Regular maintenance ensures the longevity and performance of your Bomber Air Trunnion rear shock. Here’s a simple maintenance routine to follow:

1. Check Air Pressure: Regularly check the air pressure with a shock pump. This helps maintain the proper sag and suspension feel. Air pressure can fluctuate due to temperature changes and riding conditions, so it’s essential to check it often.
2. Inspect for Leaks: Check the air valve for any air leaks. If you notice any loss of pressure, the valve might need servicing. A needle tool can be used to maintain or replace the air valve if necessary.
3. Clean and Lubricate: Clean the shock body and the surrounding area after every ride. Use a soft brush to remove dirt, dust, or mud. Apply a thin layer of suspension-safe grease to the shock’s bushings and mounts to reduce wear.
4. Change Suspension Fluid: Over time, the shock’s fluid will break down and lose its effectiveness. Marzocchi recommends changing the suspension fluid every 50–100 hours of riding, depending on use. Ensure that you use the proper fluid recommended by Marzocchi for optimal performance.
5. Seal Maintenance: Check the shock’s seals regularly. If you notice any leakage or excessive stiction, the seals may need replacing. Regular maintenance of the seals ensures smooth action and prevents air from leaking, keeping the shock responsive.

Troubleshooting Common Bomber Air Trunnion Issues

While the Bomber Air Trunnion is a robust rear shock, like any mechanical component, it can encounter issues. Below are some common problems and troubleshooting steps.

1. Loss of Air Pressure:
   • Cause: This is typically due to an issue with the air valve or the shock’s seals.
   • Solution: Inspect the air valve for any visible damage or leakage. If the valve is damaged, it may need replacement. Also, check the seals around the shock body for signs of wear or dirt.
2. Excessive Rebound or Stiffness:
   • Cause: Incorrect rebound settings or dirty internal components can cause the shock to feel too fast or too slow.
   • Solution: Adjust the rebound dial to the appropriate setting. If the issue persists, it might be time to clean and re-lubricate the shock internals.
3. Loss of Performance (Damping Issues):
   • Cause: A reduction in performance, such as reduced compression damping, can occur if the shock fluid breaks down.
   • Solution: Replace the shock oil and ensure that the shock is properly bled. Recheck the compression settings and adjust accordingly.
4. Squeaking or Noise:
   • Cause: Noise can arise from improper lubrication, dirt accumulation, or worn bushings.
   • Solution: Clean the shock and surrounding areas thoroughly. Lubricate the shock mounts with suspension-safe grease and check the bushings for wear. If they are worn, replace them to eliminate the noise.

Customization and Optimization for Performance

To get the most out of your Bomber Air Trunnion rear shock, customization is key. Here are some tips for optimizing your shock for different riding styles:

1. For Aggressive Riders: If you’re an aggressive rider who tackles rough trails, increase the compression and reduce the rebound. This setup helps control the shock’s response during harsh landings and big hits.
2. For Cross-Country Riders: Cross-country riders often benefit from a softer compression setting with faster rebound for better control on smoother terrain. Consider reducing the air pressure slightly for increased comfort and responsiveness.
3. Fine-Tuning for Weight: Riders of varying weight should adjust the air pressure accordingly. Heavier riders may need higher air pressures to prevent bottoming out, while lighter riders may opt for lower pressures for a more compliant ride.

Compatibility with Other Drivetrain Components

The Bomber Air Trunnion rear shock is designed to work seamlessly with various frames and drivetrain components, but compatibility considerations are still important. When installing or replacing your shock, ensure that the mounting system (trunnion or eyelet) is compatible with your bike’s rear triangle. Additionally, check for clearance with the bike’s chainstay and other rear suspension components to avoid interference during travel.

Conclusion

Servicing and maintaining your Bomber Air Trunnion rear shock requires attention to detail, but with proper care, it will provide superior performance for your bike. Regularly checking the air pressure, cleaning, and maintaining the seals and suspension fluid will ensure long-lasting, efficient operation. Whether you’re tuning it for comfort or performance, understanding the shock’s unique features and troubleshooting common issues will help you get the most out of your ride.