The Marzocchi Bomber CR Trunnion [paid link] rear shock is a high-performance suspension component designed to provide excellent damping and control for aggressive riding and mountain biking. However, like all high-end components, it can occasionally encounter issues that impact performance. This guide covers common problems riders may face with the Bomber CR Trunnion [paid link] rear shock, along with solutions for troubleshooting and maintenance. By addressing these issues, you can keep your shock working smoothly and optimize its performance.
1. Lack of Suspension Response
A lack of suspension response, or feeling like the shock is too stiff or unresponsive, can significantly affect the ride quality. This problem can stem from a variety of causes.
Possible Causes:
- Incorrect air pressure: The air pressure in the shock plays a crucial role in its performance. Too much air pressure can make the shock feel overly stiff, while too little can cause bottoming out.
- Clogged or worn seals: If the seals are damaged or dirty, the shock may lose its ability to rebound and compress effectively.
- Damaged internals: Internal issues such as a broken damper or worn-out components can reduce responsiveness.
Solutions:
- Check air pressure: Use a shock pump to verify the air pressure. Refer to the manufacturer’s recommended PSI based on your weight and riding style. Adjust the pressure as necessary.
- Inspect seals: Clean the shock and inspect the seals for any signs of damage or wear. If necessary, replace the seals.
- Service the shock: If internal components are worn or damaged, it’s time for a full service. Consider sending the shock to a professional for servicing.
2. No Rebound or Excessive Rebound
Rebound control allows the shock to return to its original position after compression, ensuring smooth handling and preventing unwanted bouncing. A malfunctioning rebound can lead to an overly stiff shock or excessive bouncing.
Possible Causes:
- Rebound dial misadjustment: If the rebound dial is set too fast or too slow, it can affect how the shock rebounds after compression.
- Low or high oil levels: Rebound damping relies on appropriate oil levels. If the oil level is too low, rebound may be sluggish. Too much oil can result in excessive rebound.
- Worn rebound damper: A worn-out or damaged damper may fail to control the shock’s rebound effectively.
Solutions:
- Adjust the rebound dial: Start by adjusting the rebound dial to the middle setting. From there, make fine adjustments by turning it one click at a time, either faster or slower, until you achieve the desired rebound performance.
- Check oil levels: Ensure the oil is at the correct level as per the manufacturer’s guidelines. If necessary, top up or change the oil.
- Replace the damper: If the damper is severely worn or damaged, replacement may be necessary. Consult a professional if you are unsure about the damper’s condition.
3. Bottoming Out
Bottoming out occurs when the shock compresses too much and reaches the end of its travel, which can lead to a harsh ride and potential damage to the shock and bike frame.
Possible Causes:
- Incorrect air pressure: If the air pressure is too low, the shock will not be able to support the rider’s weight properly, causing it to bottom out.
- Damaged or insufficient compression damping: If the compression damping is not set properly, the shock may not resist compression enough to prevent bottoming out.
- Shock oversize or incompatibility: A shock that is too small for the bike’s geometry or has incorrect sizing for the frame can result in poor suspension performance, including bottoming out.
Solutions:
- Increase air pressure: Check and adjust the air pressure to ensure it is within the recommended range for your weight. A higher air pressure can help prevent bottoming out.
- Adjust compression damping: Fine-tune the compression damping settings to provide more resistance as the shock compresses. This adjustment will help the shock resist bottoming out under heavy impacts.
- Check shock fitment: Verify that the shock is compatible with your bike’s frame. A shock with incorrect sizing may not perform correctly and could result in bottoming out.
4. Sag Issues
Sag refers to how much the shock compresses under the rider’s weight when the bike is at rest. Proper sag ensures the suspension is optimized for both comfort and performance. Too much or too little sag can compromise the shock’s performance.
Possible Causes:
- Incorrect air pressure or spring rate: Too much air pressure or an incorrect spring rate can result in insufficient sag, making the bike feel harsh and unresponsive.
- Improper rider weight adjustments: If the shock is not adjusted to match the rider’s weight, the sag may be too high or too low.
Solutions:
- Set correct air pressure: Use the recommended air pressure as a baseline. Fine-tune the pressure based on your specific riding style and weight. Aim for around 25-30% of the total shock travel as sag.
- Reevaluate rider weight settings: Ensure the shock settings, including the air pressure and rebound damping, are adjusted according to your weight and riding style. Adjusting the spring rate might also be necessary if you’re using a coil shock.
5. Noise from the Shock
Unusual noises from the rear shock can be bothersome and often indicate an underlying issue. These noises could range from squeaks to knocking sounds.
Possible Causes:
- Lack of lubrication: The shock’s moving parts, including the bushings and seals, may require lubrication to prevent friction and noise.
- Loose hardware: Loose bolts or mounting hardware can create knocking or rattling sounds.
- Damaged bushings or seals: Worn or damaged bushings and seals can lead to noise during compression and rebound.
Solutions:
- Lubricate the shock: Apply a small amount of suspension grease to the shock’s moving parts, including the bushings and seals, to reduce friction and eliminate squeaks.
- Tighten hardware: Inspect all mounting bolts and fasteners to ensure they are torqued to the proper specifications. Loose hardware can cause rattling or knocking sounds.
- Replace worn bushings: If the bushings or seals are damaged, replace them to eliminate the noise and restore smooth operation.
6. Leaking Oil or Air
A rear shock leaking oil or air can drastically reduce its performance and lead to further damage if not addressed promptly.
Possible Causes:
- Worn seals: The seals around the shock’s shaft or air canister may wear out over time, allowing oil or air to escape [paid link].
- Improper assembly: If the shock was not assembled correctly, it could result in oil or air leakage.
- Physical damage: Impacts or crashes can cause damage to the shock body, leading to leaks.
Solutions:
- Inspect and replace seals: Carefully inspect the seals for damage or wear. If the seals appear to be compromised, replace them to restore proper function.
- Rebuild the shock: If the seals are worn or damaged beyond repair, it might be necessary to rebuild the shock. Consult a professional technician for a rebuild.
- Check for damage: Inspect the shock for any visible damage to the shock body. If damage is found, the shock may need to be replaced.
7. Decreased Pedaling Efficiency
Pedaling efficiency is critical for maximizing energy transfer and overall ride performance. A decrease in efficiency can be caused by improper shock settings.
Possible Causes:
- Too much compression damping: Excess compression damping can cause the shock to resist movement unnecessarily, reducing pedaling efficiency.
- Shock is too soft: If the shock is too soft, it can create unwanted movement during pedaling, leading to decreased efficiency.
Solutions:
- Adjust compression damping: If the shock is too stiff during pedaling, adjust the compression damping to allow for smoother movement. Set it to a level that minimizes pedal bob but still offers comfort during rough terrain.
- Increase air pressure: Ensure the air pressure is at an optimal level to prevent the shock from feeling too soft and bogging down during pedaling.
By following these troubleshooting steps, riders can resolve common issues with the Marzocchi Bomber CR Trunnion rear shock and keep it performing at its best. Regular maintenance and careful adjustments will ensure that the shock provides optimal performance on every ride.