The Fox DHX2 Trunnion [paid link] rear shock is a high-performance component designed for serious mountain bikers who demand precision and reliability in their suspension system. Known for its exceptional adjustability, durability, and ability to fine-tune ride characteristics, the DHX2 Trunnion [paid link] offers an impressive level of customization for riders seeking the best in rear shock technology. Whether you’re installing, maintaining, or troubleshooting this shock, this comprehensive guide will cover everything you need to know to optimize its performance.

Installation of the DHX2 T

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runnion Rear Shock

Tools Required:

• 8mm and 10mm wrenches
• Torque wrench [paid link]
• 5mm and 6mm Allen wrenches [paid link]
• Suspension grease
• Rags for cleaning

Step-by-Step Installation:

1. Remove the old shock: If you’re replacing an existing rear shock, begin by removing the bolts securing the old shock to the frame. Use the appropriate size Allen wrench [paid link] to loosen and remove the mounting hardware.
2. Prepare the shock: Before installation, apply a light coating of suspension grease to the shock bushings. This helps ensure smooth movement and prevents wear on the frame.
3. Install the DHX2 Trunnion shock: Align the shock’s trunnion mount with the frame’s shock mount. Insert the mounting bolts and secure them by hand first.
4. Tighten the bolts: Using a torque wrench [paid link], tighten the bolts to the manufacturer’s specified torque setting. This is typically around 200-220 inch-pounds for most DHX2 installations, but always check the specific torque specs for your bike model.
5. Check alignment: Ensure that the shock is aligned properly and not binding when the suspension moves. The trunnion mount should sit evenly within the frame’s shock mount without any noticeable gaps.
6. Test the suspension: After installation, test the suspension by compressing the rear shock by hand to make sure everything is functioning smoothly. Check for any unusual sounds, like grinding or binding.

Adjustment and Tuning of the DHX2 Trunnion Rear Shock

The DHX2 Trunnion is highly adjustable, allowing riders to fine-tune their suspension settings for different trail conditions and riding styles. The shock features multiple adjustments, including rebound, compression, and volume spacers.

Rebound Adjustment:

The rebound adjuster, located at the bottom of the shock, controls how quickly the shock returns to its fully extended position after compression. To adjust:

• Turn the rebound knob clockwise to slow down the rebound (useful for aggressive riders or rougher terrain).
• Turn it counterclockwise to speed up the rebound (ideal for smoother trails or lighter riders).

Compression Adjustment:

The DHX2 has both high and low-speed compression adjustments. These settings control the shock’s resistance to compression, helping you customize the ride to your preferences.

• Low-speed compression: This controls the shock’s compression at slower speeds and is useful for maintaining traction on technical climbs and descents. Adjust this setting by turning the dial on the shock body. A higher setting stiffens the shock, making it more resistant to compression.
• High-speed compression: This affects how the shock responds to quick, harsh impacts, such as landings from drops or hard hits. You can adjust the high-speed compression with a separate knob, typically located near the top of the shock. Dial it in to prevent bottoming out on aggressive terrain.

Volume Spacers:

The DHX2 Trunnion comes with volume spacers that allow you to adjust the shock’s progressiveness. Adding spacers makes the shock more progressive, preventing bottom-outs during heavy impacts. Removing spacers provides a more linear feel, better for lighter riders or less aggressive trails. Adjust the spacers by removing the air canister of the shock and inserting or removing the required spacers.

Maintenance of the DHX2 Trunnion Rear Shock

Regular maintenance is crucial to keep the DHX2 Trunnion performing at its peak [paid link]. Fox recommends servicing your shock at least once every 100 hours of riding, or more frequently if you ride in harsh conditions.

Cleaning:

• Regularly wipe down the shock after each ride to remove dirt, mud, and debris. Use a damp rag to avoid getting water into the shock’s internals.
• Keep the air canister and shock shaft clean to ensure smooth operation.

Oil and Seal Maintenance:

• Perform an oil change every 50-100 hours of riding to ensure proper lubrication of the internal components.
• Inspect the seals for wear during regular maintenance intervals. If you notice oil leaks or poor performance, consider replacing the seals or sending the shock to Fox for a professional rebuild.

Spring and Air Pressure:

• Check the air pressure regularly. Incorrect air pressure can lead to poor performance or damage to the shock.
• Use a shock pump to adjust the air pressure based on your weight and riding preferences. Make sure the shock is set to the recommended pressure range specified by Fox.

Troubleshooting Common DHX2 Trunnion Rear Shock Issues

1. Lack of Rebound Control

If the shock doesn’t rebound smoothly or feels too fast or slow:

• Check the rebound setting: Ensure it’s set correctly for your riding style.
• Inspect for oil leaks: If the shock is leaking oil, it may not perform properly and should be serviced.

2. Suspension Bottoms Out

If the shock bottoms out too easily, it may be due to:

• Low compression settings: Try increasing the low-speed compression.
• Incorrect air pressure: Make sure you’re running the correct air pressure for your weight and riding style.
• Too few volume spacers: Adding more spacers can help prevent bottoming out.

3. Excessive Noise or Squishy Feel

If you hear unusual sounds or feel a squishy, unresponsive suspension:

• Check the shock’s seals: Worn-out seals can let air or oil escape [paid link], leading to inconsistent performance.
• Inspect the mounting hardware: Loose bolts can cause movement in the shock, leading to noise or instability.

Customization and Optimization of the DHX2 Trunnion Rear Shock

The DHX2 Trunnion allows for a great degree of customization, especially when considering different riding disciplines or terrain types. Riders can swap volume spacers to fine-tune the shock’s progression or adjust the compression settings to match the demands of a given trail.

For aggressive downhill riders, using a firmer compression setting with more volume spacers may offer better bottom-out resistance during big hits. For cross-country or trail riders, removing spacers and dialing back compression can yield a more responsive, smoother ride suited for climbing and fast descents.

Compatibility with Other Drivetrain Components

The DHX2 Trunnion is designed to work seamlessly with a wide range of mountain bike frames. However, it’s important to ensure the shock is compatible with the frame’s suspension design, specifically regarding the shock’s trunnion mount. The trunnion design is a newer standard and is not compatible with older frames that use a traditional eyelet mounting system.

When considering compatibility with other drivetrain components, such as the fork and wheels, ensure that the shock’s setup matches your bike’s geometry and intended use. The DHX2 Trunnion is primarily designed for aggressive riding and works well with high-performance drivetrain setups designed for demanding trails.

Comparison with Similar Models

Compared to other high-end rear shocks in its class, such as the RockShox Super Deluxe or the Cane Creek Double Barrel, the Fox DHX2 Trunnion stands out due to its precise adjustability and excellent build quality. While the Super Deluxe is known for its lighter weight and efficiency in cross-country applications, the DHX2 Trunnion shines in providing unparalleled control and performance for aggressive downhill riders. The Cane Creek Double Barrel offers similar customization options, but some riders prefer the DHX2’s smoother feel and higher overall durability, particularly in harsh conditions.

The DHX2 Trunnion’s strong reputation stems from its reliable performance, high customization range, and the backing of Fox’s renowned suspension technology.