The STX22 Air rear shock from Öhlins is engineered for high-performance cyclists who demand superior control and comfort. Regular maintenance, including oil changes, is essential to ensure that the shock continues to perform at its best. Changing the oil not only prolongs the life of the shock but also maintains the consistency of its performance. This step-by-step guide will walk you through the process of changing the oil on your STX22 Air rear shock.

Tools Required

To perform the oil change on your STX22 Air rear shock, you will need the following tools:

• 8mm Allen wrench [paid link]
• 10mm Allen wrench [paid link]
• 2mm Allen wrench
• Torque wrench [paid link]
• 24mm spanner wrench
• Clean container for draining oil
• Suspension oil (Öhlins recommends specific types)
• Rag or paper towels
• Small flat-head screwdriver
• Syringe or oil injector tool
• Snap ring pliers
• Oil seals and O-rings (if replacement is needed)

Preparation

Before starting the oil change, ensure the shock is removed from the bike and is clean. This ensures that no dirt or debris enters the shock during the process. Work in a clean, well-lit area to avoid contamination.

Step 1: Remove the Rear Shock

1. Begin by removing the rear shock from the bike. Use the appropriate tools to disconnect the shock from both the top and bottom mounts.
2. Lay the shock on a clean surface, such as a workbench, to begin the oil change process.

Step 2: Disassemble the Shock

1. Using the 8mm and 10mm Allen wrenches [paid link], carefully remove the shock’s bolts and end caps.
2. Once the shock is detached from its mountings, use the 2mm Allen wrench to remove any smaller screws or components securing the air sleeve and damper components.
3. Gently slide off the air sleeve from the damper body. Be cautious to avoid damaging the internal parts during disassembly.

Step 3: Drain the Old Oil

1. With the shock disassembled, place the shock into a clean container to catch any old oil as it drains out.
2. Use a small flat-head screwdriver to loosen any parts securing the oil seal in place.
3. Once the oil seal is removed, allow the shock to drain completely. Depending on the shock’s usage, this could take several minutes to ensure all the oil is out.

Step 4: Clean the Components

1. Once the shock is drained, use a clean rag or paper towels to wipe down the components. Ensure all traces of old oil are removed from the shock body and other internal parts.
2. Inspect the oil seals and O-rings for wear. If they appear damaged or worn, replace them with new ones. This is crucial to maintaining the shock’s performance and preventing leaks.

Step 5: Reassemble the Shock

1. Apply fresh suspension oil to the oil seals and O-rings before reassembling the shock. Be sure to use the type of oil recommended by Öhlins for the STX22 Air model.
2. Slide the air sleeve back onto the damper body carefully. Ensure that the O-rings are seated properly to avoid leaks.
3. Once the air sleeve is back in place, reinstall any screws or bolts that were removed earlier. Tighten them to the manufacturer’s recommended torque settings using a torque wrench [paid link] to ensure the correct pressure.

Step 6: Refill the Shock with Oil

1. Use a syringe or oil injector tool to fill the shock with the recommended amount of suspension oil. Öhlins typically specifies the exact volume required for the STX22 Air shock model.
2. Slowly fill the shock, ensuring that there are no air bubbles present in the oil. Overfilling can lead to improper shock behavior, while underfilling can result in poor performance.

Step 7: Final Seal and Assembly

1. After filling the shock with oil, replace the oil seal and any other parts removed during the disassembly process. Ensure that everything is properly aligned.
2. Secure the components with snap ring pliers or the appropriate tool to lock the oil seals in place.

Step 8: Test the Shock

1. After reassembly, it is important to test the shock’s functionality. Before reinstalling it on the bike, compress and extend the shock a few times by hand to check for any unusual resistance or oil leakage.
2. Check the air pressure in the shock and adjust it according to your riding preferences.

Step 9: Reinstall the Shock

1. Reinstall the shock back onto the bike. Tighten the top and bottom mounting bolts to the correct torque settings.
2. Once the shock is securely mounted, ensure that it is properly aligned and functioning smoothly.

Troubleshooting Common Oil Change Issues

Even when following the procedure carefully, there may be a few issues that arise during the oil change process. Here are some common troubleshooting tips:

Oil Leaks

• If you notice oil leakage after reassembling the shock, it could be due to improperly seated seals or O-rings. Double-check that the seals were installed correctly and replace any worn-out parts.
• Ensure that the air sleeve is properly aligned with the damper body, as misalignment can also cause leaks.

Air Pressure Problems

• If the shock does not hold air pressure after the oil change, check for leaks in the air valve or air sleeve. Ensure that the valve is tightly sealed and the air sleeve is properly assembled.

Inconsistent Damping Performance

• If you experience inconsistent damping performance, ensure that the correct oil type and amount were used. Incorrect oil can drastically affect the shock’s performance, so it is important to adhere to Öhlins’ specifications.

Conclusion

Performing an oil change on the Öhlins STX22 Air rear shock is a vital part of its maintenance. By following these steps carefully, you can ensure that your shock continues to perform at its peak, offering superior comfort and control on every ride. Regular maintenance, including oil changes, helps prolong the life of the shock, prevents performance degradation, and optimizes ride quality. Always use the recommended oils and replacement parts to maintain the shock’s efficiency and ensure smooth operation on challenging trails.