Rebuilding your Fenix COIL [paid link] rear shock is a highly effective way to restore the shock’s performance and prolong its lifespan. Whether you’re an experienced rider or a beginner, performing this task at home can save you both time and money. In this guide, we will cover all the necessary steps for rebuilding your Fenix COIL [paid link] rear shock, ensuring that you get the best out of your suspension system.

Tools Required

• Fenix COIL rear shock rebuild kit
• 8mm and 10mm wrenches
• Shock pump
• Torque wrench [paid link]
• 3mm and 5mm hex wrenches
• Clean rags
• Suspension fluid (compatible with the Fenix COIL)
• Sealant grease (suitable for suspension components)
• C-clamp or vice (optional for compression assembly)
• Rebound and compression tuning tools (optional)
• Air compressor (optional for recharging air chambers)

Disassembly of the Fenix COIL Rear Shock

Before starting the rebuild process, it’s essential to remove the shock from the bike. Here’s how to disassemble the shock properly.

1. Remove the shock from the frame
   Begin by removing the rear wheel to allow for better access to the shock. Then, use the appropriate hex wrenches to disconnect the shock from both the upper and lower mounts. Carefully remove the shock from the frame and place it on a clean, stable surface.
2. Drain the air pressure
   Use a shock pump to slowly release all air pressure from the shock. It’s essential to fully depressurize the shock to avoid injury or damage during disassembly.
3. Remove the spring
   If your Fenix COIL is a coil spring shock, carefully remove the coil by unscrewing the preload collar. Once the collar is free, the coil should slide off. Place the spring in a safe location to prevent any damage during the rebuild process.
4. Loosen the shock body
   Use a 10mm wrench to remove the bolts that hold the shock body and reservoir together. This will allow access to the internal components that need to be serviced.

Inspection of the Shock Components

Now that the shock is disassembled, it’s time to inspect the components for wear or damage.

1. Check the damper
   Inspect the damper for any signs of oil leaks or wear. A damaged damper may need to be replaced or reconditioned. You should feel smooth resistance when manually compressing the shock, with no jerky movements.
2. Examine the coil spring
   Look for any cracks or deformities in the coil spring. Coil springs generally last a long time, but any signs of damage may necessitate a replacement.
3. Inspect seals and bushings
   Check all seals, o-rings, and bushings for signs of wear, cracks, or leaks. Seals are vital for maintaining the proper air and fluid pressure inside the shock. If any seals are damaged, replace them using the rebuild kit.

Rebuilding the Fenix COIL Rear Shock

With the shock components inspected and prepared, you can begin the rebuilding process.

1. Clean and lubricate all parts
   Thoroughly clean the shock body, spring, damper, and all other components with a clean rag. Ensure all parts are free from dirt and debris. Once cleaned, apply a light layer of suspension grease to all moving parts, seals, and bushings to ensure smooth operation.
2. Replace the internal seals
   Using the rebuild kit, carefully replace all internal seals and o-rings. The seals should be seated securely in their respective grooves. Make sure the new seals are properly lubricated with suspension grease before installation.
3. Reassemble the shock body
   Once the seals and o-rings are in place, reassemble the shock body and reservoir. Tighten the bolts to the manufacturer’s recommended torque specifications using a torque wrench [paid link]. Ensure that all components are tightly sealed to avoid air or fluid leakage.
4. Reinstall the coil spring
   Slide the coil spring back onto the shock body and secure it with the preload collar. Adjust the preload collar to the desired tension to match your riding preferences.
5. Fill with suspension fluid
   Add the appropriate suspension fluid to the shock as per the manufacturer’s guidelines. The fluid is essential for the shock’s damping performance. Use the specified amount and ensure no air bubbles are trapped inside during filling.
6. Reinstall the shock’s mounting hardware
   Once the shock body is fully reassembled, reinstall it back onto the bike frame. Use the appropriate wrenches and torque the mounting bolts to the manufacturer’s specified torque values.

Recharging and Tuning the Fenix COIL Rear Shock

After rebuilding your Fenix COIL rear shock, it’s time to set the correct air pressure and perform some tuning.

1. Set the air pressure
   Attach the shock pump to the air valve on the shock. Set the desired air pressure according to your body weight and riding style. For most riders, a pressure between 150-250 PSI is typical, but refer to your manual for precise specifications.
2. Adjust rebound and compression settings
   If your Fenix COIL has external rebound and compression adjustment dials, begin by setting them to the manufacturer’s recommended baseline settings. From there, you can fine-tune the shock based on your preferences. Adjust the rebound damping for a smooth return after compression, and tweak the compression damping for a more responsive or plush ride.

Troubleshooting Common Fenix COIL Rear Shock Issues

After your shock is rebuilt, it’s important to be aware of common issues that may arise.

1. Air pressure loss
   If the shock loses air pressure quickly, inspect the seals, particularly the air valve seal, for any damage. Replacing faulty seals can often resolve this issue.
2. Sticky or jerky shock movement
   If the shock feels sticky or jerky during compression, this could indicate a lack of proper lubrication or worn internal components. Inspect the damper and replace it if necessary.
3. Excessive rebound
   If the shock rebounds too quickly, adjust the rebound damping to a slower setting. If this doesn’t resolve the issue, there may be an internal problem, such as damaged valves or a need for more suspension fluid.

Conclusion

Rebuilding your Fenix COIL rear shock at home can be a rewarding experience, offering you the ability to refresh your shock and maintain optimal performance. By following the steps outlined in this guide, you can ensure that your shock remains in excellent working condition for many rides to come. Regular maintenance, such as cleaning, lubrication, and seal replacement, will help prolong the life of your shock and improve your overall riding experience.