DIY Rear Shock Tuning: Get the Most from Your Bomber CR Coil

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The Marzocchi Bomber CR Coil [paid link] is a high-performance rear shock designed for aggressive riders seeking precision and durability on tough terrains. Whether you’re aiming for smoother rides or tackling rough descents, fine-tuning this rear shock to your specific riding style can significantly improve your performance. This guide will walk you through the steps of installation, adjustment, maintenance, troubleshooting, and optimization of the Bomber CR Coil [paid link]. It also compares this model with other popular options to help you make the best decisions for your setup.

Tools Required

  • 5mm Allen wrench [paid link]
  • 6mm Allen wrench [paid link]
  • Shock pump
  • Torque wrench [paid link]
  • Rags for cleaning
  • Isopropyl alcohol
  • Suspension grease
  • Metric spanner or socket wrench
  • Dropper seatpost (if necessary for compatibility)

Installation of the Marzocchi Bomber CR Coil

Installing the Bomber CR Coil is relatively straightforward, but it requires precision to ensure the shock works effectively and safely.

1. Remove the Old Shock

  • Use the 5mm Allen wrench to unscrew the bolts securing the old shock to your bike’s rear triangle.
  • Carefully remove the shock from the frame, keeping in mind any additional spacers or washers that might be used.

2. Install the New Bomber CR Coil

  • Ensure that the Bomber CR Coil is compatible with your bike frame’s mounting standards (check eyelet diameter and shock length).
  • Position the Bomber CR Coil in place and secure it with the mounting bolts.
  • Tighten the bolts to the manufacturer’s recommended torque settings, which can typically be found in the product manual or online specifications.

3. Set the Sag

  • The ideal sag setting is critical for the best performance of your shock. Using a shock pump, set the pressure according to your weight and riding style.
  • The Bomber CR Coil typically comes with a preload adjuster to dial in the spring tension.
  • To set the sag, use the “sag-o-meter” or a zip tie on the shock shaft. Adjust the preload until the sag is around 30-35% of the total shock stroke.

Adjustments for Optimal Performance

Fine-tuning your Marzocchi Bomber CR Coil is essential to achieve the best ride quality and response.

Compression Adjustment

The Bomber CR Coil comes equipped with an external compression adjuster, which helps manage how the shock compresses during impacts. This setting controls how stiff or soft the shock feels when the bike is subjected to bumps.

  • Increase Compression: Turn the compression knob clockwise to stiffen the shock, improving stability during fast descents and reducing bottoming out. This is useful on smoother trails or aggressive riders.
  • Decrease Compression: Turn the compression knob counterclockwise to soften the shock, offering more plushness and comfort on rough terrain or technical trails.

Rebound Adjustment

The rebound knob on the Bomber CR Coil controls the speed at which the shock returns after compression. Fine-tuning rebound is crucial for maintaining traction and preventing the bike from bouncing uncontrollably.

  • Increase Rebound: Turn the rebound adjuster clockwise to slow the shock’s return, which can improve control and reduce unwanted bouncing.
  • Decrease Rebound: Turn the rebound adjuster counterclockwise to speed up the return, allowing the shock to recover faster after compressions.

Preload Adjustment

Preload affects the amount of initial tension in the shock spring. Adjusting preload allows you to fine-tune the shock to your weight and riding style.

  • Increase Preload: Tightening the preload will reduce sag, making the shock feel stiffer and more responsive on smooth terrain.
  • Decrease Preload: Loosening the preload will increase sag, providing a more comfortable ride on rough and technical sections.

Maintenance of the Bomber CR Coil

Regular maintenance is crucial for ensuring the longevity and performance of your rear shock.

Cleaning

  • Periodically clean the shock with a damp rag and isopropyl alcohol to remove dirt, dust, and debris from the shock body.
  • Ensure that no dirt or mud accumulates around the seals or the eyelet to avoid damaging the internal components.

Lubrication

  • Apply suspension-specific grease to the shock bushings and mounting hardware. This ensures smooth operation and reduces wear over time.

Coil Spring Inspection

  • Inspect the coil spring for any visible damage, such as cracks or scratches. Replace the coil spring if any issues are found, as this could affect performance and safety.

Air Can Service

While the Bomber CR Coil uses a coil spring instead of an air spring, the damper’s oil still needs to be changed periodically. Refer to the Marzocchi manual for service intervals based on riding conditions.

Troubleshooting Common Issues

If you encounter issues with the Bomber CR Coil, consider these common problems and their solutions.

Lack of Rebound Control

If your shock rebounds too quickly or too slowly, check the rebound adjuster. It may be set incorrectly, or internal oil may need to be replaced if the rebound control feels inconsistent.

Bottoming Out

Excessive bottoming out can occur if the spring is too soft or if the compression damping is set too low. Increase compression or replace the coil with a stiffer option to prevent this issue.

Squeaky Shock

Squeaks may come from worn-out seals or lack of lubrication on the mounting hardware. Clean and lubricate the shock’s bushings and check for any signs of wear.

Customization for Better Performance

The Bomber CR Coil is highly customizable, which means you can adjust it based on your specific riding needs. Here are some customization options:

Spring Rate

Selecting the correct spring rate for your weight is crucial for achieving optimal performance. Marzocchi offers various coil spring options. A heavier spring is suitable for heavier riders, while a lighter spring offers more comfort and better small-bump sensitivity.

Damping Adjustment

For riders who prefer a more aggressive setup, fine-tuning the compression and rebound settings can help you achieve the desired performance. Experiment with settings to find the balance between plushness and support.

Mounting Position

The Bomber CR Coil features different mounting positions to adjust the shock’s stroke and overall geometry. Changing the mounting position can alter the bike’s handling, making it more stable or nimble depending on your preference.

Comparison with Other Rear Shocks

The Marzocchi Bomber CR Coil stands out in terms of durability and adjustability. Compared to air shocks, the coil system offers more consistent performance over time, particularly for aggressive riders.

  • Fox DHX2: Offers a similar performance level but may be more complex to tune due to its additional adjustments. The Bomber CR Coil is simpler to dial in.
  • RockShox Super Deluxe Coil: Known for a smoother, more plush feel, but it lacks the high-end damping controls of the Bomber CR Coil, making the Marzocchi a more versatile [paid link] option for rougher terrain.

Compatibility with Other Drivetrain Components

When setting up the Bomber CR Coil, it’s important to ensure compatibility with your other drivetrain components. The coil spring system doesn’t interact directly with the drivetrain, but suspension setup can affect overall bike handling. Make sure your frame’s rear triangle and pivot points support the shock’s mounting standards and ensure proper frame geometry for best performance.

In conclusion, fine-tuning your Marzocchi Bomber CR Coil involves adjusting preload, compression, and rebound settings to your preference. Regular maintenance, including cleaning and lubrication, will extend the life of the shock and ensure it performs optimally for years to come.