Preventative Maintenance for Tune Shock SK18 Rear Shocks

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The Tune Shock SK18 [paid link] rear shock from the Trunnion brand is known for its high-performance features, making it a popular choice for mountain bikers seeking precision, durability, and comfort on rough trails. To keep your shock working optimally and to extend its lifespan, performing regular maintenance is essential. This guide will walk you through the preventative maintenance practices that will ensure your Tune Shock SK18 [paid link] continues to perform at its best.

Understanding the Tune Shock SK18 Rear Shock

The Tune Shock SK18 is designed for aggressive riding and features a unique trunnion mount for improved shock absorption. It incorporates a high-quality damper, air spring system, and multiple adjustments to fine-tune performance based on riding style and terrain. Regular maintenance ensures that all these features work in harmony, providing maximum comfort and control on technical descents and climbs.

Tools Required

Before diving into the maintenance steps, gather the following tools:

  • Torque wrench [paid link]
  • Shock pump
  • 5mm and 6mm Allen wrenches [paid link]
  • Suspension fluid (specific to Tune brand recommendations)
  • Degreaser
  • Clean rags or cloths
  • Small brush
  • Latex gloves
  • Isopropyl alcohol
  • Teflon tape or sealant (for air can maintenance)
  • Specialized suspension grease (if required for the model)

Step-by-Step Guide to Preventative Maintenance

1. Cleaning the Shock

Regular cleaning is crucial for preventing dirt and debris from entering the shock’s seals and compromising performance.

  • Step 1: Remove the shock from the bike. Use a 5mm Allen wrench [paid link] to remove the bolts securing the shock in place.
  • Step 2: Use a clean rag to wipe off any visible dirt or debris. Make sure to clean around the air valve, the body of the shock, and the mounting hardware.
  • Step 3: Spray the shock with a mild degreaser and wipe it down with a rag. Avoid spraying the shock directly with high-pressure water, as it can force dirt into the seals.
  • Step 4: Use a small brush to clean around the shock body and the pivot points where dirt tends to accumulate.

2. Air Pressure Check

Maintaining proper air pressure is essential for optimal suspension performance.

  • Step 1: Use a shock pump to check the air pressure in the air spring. Refer to the manufacturer’s guidelines for recommended pressure based on rider weight and riding style.
  • Step 2: If the air pressure is low, add the recommended amount of air. Be cautious not to exceed the maximum pressure limit specified by the manufacturer.
  • Step 3: After inflating, press the shock down to check if it rebounds properly. If there is sluggish movement or no rebound, it may indicate a need for servicing.

3. Inspecting the Seals

The seals on the Tune Shock SK18 help keep dirt, moisture, and debris out of the shock’s internal components. Inspecting the seals regularly ensures that they are in good condition.

  • Step 1: Use isopropyl alcohol and a clean rag to wipe down the shaft and around the seals. This will remove any grease or dirt that might have accumulated.
  • Step 2: Check the seals for wear and damage. If the seals are cracked, dried out, or missing, replace them immediately. Damaged seals can lead to air and fluid leakage, affecting shock performance.

4. Rebuilding the Shock

Over time, the shock’s internal components—such as the damper and air spring—may require a rebuild. Rebuilding the shock can improve responsiveness and extend its life. If you’re not experienced with suspension maintenance, it’s advisable to have a professional service the shock. However, for those who wish to tackle the task, follow these steps:

  • Step 1: Use the appropriate tools to remove the air canister from the shock. This usually requires the removal of bolts around the shock body and air chamber.
  • Step 2: Once the air canister is removed, drain any remaining air from the shock and use a clean rag to wipe down the internals.
  • Step 3: If the shock has a serviceable damper cartridge, carefully remove it and clean it with a suspension fluid. Apply fresh suspension fluid to the internal parts, following the manufacturer’s recommendations for oil type and amount.
  • Step 4: Reassemble the shock by reversing the steps for removal, ensuring everything is properly tightened with the correct torque specifications.

5. Lubing the Shock

Regular lubrication of the shock’s moving parts is essential for smooth operation.

  • Step 1: Apply a small amount of suspension-specific grease to the bushings and pivot points where the shock mounts to the frame.
  • Step 2: Be cautious not to over-lubricate, as excess grease can attract dirt and debris. A light coat will suffice for optimal performance.

6. Checking the Rebound and Compression Settings

The Tune Shock SK18 features adjustable rebound and compression settings to fine-tune the suspension’s performance. Ensuring that these adjustments are correctly set for your riding style will improve the ride feel.

  • Step 1: With the shock installed on the bike, adjust the rebound and compression dials based on your preferences and riding conditions.
  • Step 2: Test the shock by riding the bike in various conditions, paying attention to how it responds to bumps and drops. Fine-tune the settings as needed for the desired performance.

7. Storing the Shock

If you’re planning on storing your bike for an extended period, such as during the off-season, make sure to store the shock properly to prevent damage.

  • Step 1: Clean the shock thoroughly before storage.
  • Step 2: Reduce the air pressure to a safe level to prevent undue stress on the seals.
  • Step 3: Store the shock in a cool, dry place, away from direct sunlight and extreme temperatures.

Troubleshooting Common Issues

Despite proper maintenance, you may encounter certain issues with the Tune Shock SK18. Here are common problems and solutions:

1. Loss of Air Pressure

If your shock is losing air pressure, check the air valve and seals for damage. If the seals are intact and there is no visible leakage, the air valve might be faulty. In such cases, it’s recommended to replace the valve or have it serviced.

2. Poor Rebound Performance

If the rebound feels too fast or slow, it may indicate incorrect settings or an internal oil issue. Adjust the rebound damping first. If that doesn’t solve the problem, a service may be necessary to inspect the damper oil and internal components.

3. Sticking or No Movement

If the shock feels sticky or doesn’t move at all, check for air or fluid leakage and inspect the seals. Also, verify if the shock needs a full rebuild to ensure the internal components are in good condition.

Customization and Optimization

The Tune Shock SK18 can be customized for different riding styles by adjusting the air pressure, compression, and rebound settings. Riders looking for increased plushness may opt for a lower air pressure, while those seeking more efficiency on climbs may prefer a firmer setting. Experiment with different combinations to find the optimal setup that suits your riding style.

Compatibility with Other Drivetrain Components

The Tune Shock SK18 is designed to work seamlessly with a wide range of modern mountain bike drivetrains. Its trunnion mount ensures a secure connection with the bike frame, while its air spring and damper systems are compatible with various frame types and suspension designs. However, it’s essential to verify compatibility with your bike’s frame before purchasing or upgrading.

In conclusion, regular maintenance of your Tune Shock SK18 rear shock will keep it performing optimally and extend its lifespan. Cleaning, air pressure checks, seal inspections, and occasional rebuilds are key to keeping your shock in top condition. By following these preventative maintenance steps, you’ll ensure that your rear shock remains reliable and effective, providing you with a smooth and controlled ride on all your adventures.