The Marzocchi Bomber DJ suspension fork is designed to withstand the most demanding terrain while providing exceptional control and comfort. Over time, like any high-performance component, it requires routine inspection and maintenance to keep it functioning optimally. This guide will walk you through the essential steps for inspecting your Bomber DJ fork, ensuring longevity and performance.

Tools Required

• 10mm wrench
• 8mm hex wrench
• Fork fluid (specific to Bomber DJ model)
• Rag or cleaning cloth
• Fork oil syringe or pump
• Allen wrench [paid link] set
• Suspension grease
• Air pump (for adjusting pressure)
• Torque wrench [paid link]

Inspecting the Bomber DJ Suspension Fork

Visual Inspection

Before performing any in-depth maintenance, start with a visual inspection of the Bomber DJ fork. Look for the following:

• Fork Stanchions: Ensure the stanchions (the shiny tubes that slide within the fork legs) are free from scratches, dents, or any visible damage. These components are critical to the smooth operation of the fork. If damaged, they should be replaced immediately to prevent further issues.
• Seals: Check the fork seals for wear, cracks, or leaks. These seals are essential for preventing dirt and moisture from entering the internal components. A damaged seal can lead to performance issues and corrosion inside the fork.
• Crown and Steerer Tube: Inspect the crown (the top part of the fork) and steerer tube for any cracks or damage. This area must remain intact to maintain the integrity of the fork. If you find any deformation or cracks, you must replace the fork immediately.

Check Fork Travel and Damping

The Bomber DJ is a single-crown fork with adjustable travel, and it’s important to ensure both the travel and damping are functioning as they should. Here’s how you can check them:

• Travel Check: Ensure that the fork’s travel feels smooth throughout the full range of motion. Compress the fork by pressing down on the handlebars, and then slowly release. The fork should move freely without any sticking or jerking. If there’s resistance, the internal suspension might need lubrication or servicing.
• Damping Performance: Adjust the rebound and compression settings as per your usual riding preferences. Check if the fork returns to its neutral position smoothly after compressing. If the fork feels either too fast or too slow in returning, it may require a check or replacement of the damper fluid.

Inspecting the Air Spring Pressure

The air spring pressure directly affects the fork’s performance. A properly tuned air spring ensures that the fork absorbs shocks efficiently. Follow these steps to inspect and adjust the air spring pressure:

1. Release any air pressure before working on the fork by using the air valve located at the top of the fork’s right leg.
2. Reinflate the fork using an air pump to the recommended pressure, based on your weight and riding style. This information can typically be found in the Bomber DJ’s manual or on the Marzocchi website.
3. Check for leaks by pressing on the fork and listening for any hissing sound. If you hear air escaping, there could be an issue with the valve or seals, and you may need to replace the parts.

Inspecting the Lower Legs and Oil Levels

The lower legs of the Bomber DJ suspension fork house essential components like the air spring and damper. Regular oil changes are necessary for smooth function.

• Remove the lower legs by loosening the bolts at the bottom of the fork with a 10mm wrench. Take care not to strip the bolts during removal.
• Check for oil leakage or excessive wear inside the lower legs. If you notice oil buildup or signs of contamination, the fork will need an oil change.
• Oil Levels: Inspect the oil level inside the fork. Fork oil should be at the proper level to ensure smooth action and prevent unnecessary wear on internal parts. Use fork oil specific to the Bomber DJ model, and add or replace oil as needed.

Re-greasing and Cleaning

Over time, the moving parts of the Bomber DJ fork accumulate dirt and debris. Keeping these components clean and properly greased is essential for longevity.

• Clean the fork stanchions with a soft rag, paying particular attention to the seals. You can use a mild degreaser if necessary to remove any grime. Be careful not to damage the seals while cleaning.
• Grease the seals lightly with suspension grease to ensure a smooth operation and prevent wear. This will help the seals slide more effectively over the stanchions, reducing friction and prolonging their life.

Check the Brake Mount and Axle

• Brake Mount: Check the brake mount for tightness and damage. If you’re using disc brakes, ensure the mount is securely fastened, and the rotor is aligned properly. Any movement here could affect braking performance.
• Axle: Ensure that the axle is properly torqued to the manufacturer’s specifications. A loose or improperly installed axle could cause shifting issues or create instability when riding.

Test Ride for Performance

After completing the inspection, it’s time for a test ride. During the ride, pay attention to the following:

• Smoothness: The fork should feel smooth throughout the travel, with no resistance or sticking.
• Noise: Any clicking, popping, or grinding noises could indicate an issue with the internal components or fork oil.
• Fork Response: Ensure the fork is responsive to different terrain, absorbing bumps and impacts appropriately.

If the fork feels too soft or too stiff, you may need to adjust the air pressure, rebound, or compression settings.

Troubleshooting Common Set-Up Issues

Fork Not Returning to Full Extension

If the fork is not fully extending after compression, it could be a sign of low air pressure or incorrect rebound settings. Increase the air pressure slightly or adjust the rebound speed. If this doesn’t solve the issue, the internal damper might need attention.

Fork Feeling Too Stiff

If the fork feels too stiff, it could be over-inflated or the compression damping might be set too high. Check the air pressure and adjust it to your preferred level. Lowering the compression setting may also help if the fork is too harsh over smaller bumps.

Fork Leaking Oil

If you notice oil leaking from the fork, particularly from the seals or the lower leg area, the seals may be damaged or worn. In this case, you may need to replace the seals and perform an oil change. If the fork is still leaking after seal replacement, the fork might require more extensive service, such as a damper rebuild.

Customization and Optimization for Better Performance

The Bomber DJ is a versatile fork that can be customized to fit your specific riding style. Here are some ways to optimize your fork’s performance:

• Rebound and Compression Adjustments: The Bomber DJ has adjustable rebound and compression damping. Experiment with different settings to find what works best for your riding style. For aggressive riders, stiffer compression settings and faster rebound may be preferred, while trail riders may opt for a softer setup.
• Air Pressure Tuning: Adjusting the air pressure based on your body weight and riding style is key to achieving optimal performance. Lighter riders may benefit from slightly lower pressures, while heavier riders may need to increase the pressure for better support.
• Upgrading the Fork Fluid: Upgrading to higher-quality fork oil can improve performance, especially for riders who frequently ride in challenging conditions. Higher viscosity oils tend to provide better damping control.

Conclusion

Routine maintenance and inspection of your Marzocchi Bomber DJ suspension fork are crucial to keeping it in top working condition. By following this guide, you’ll be able to ensure that your fork operates smoothly, preventing costly repairs down the line and enhancing your overall riding experience. Regular inspection, oil changes, and adjustments will ensure that your Bomber DJ fork performs at its best, ride after ride.