The Arma V3 [paid link] rear shock by EXT is a high-performance, versatile [paid link] shock designed for road and trail riders who demand precision and adaptability. It offers a range of adjustments that allow riders to fine-tune the shock’s performance for different terrain, rider weight, and riding style. In this comprehensive guide, we will walk through the installation, adjustment, and maintenance of the Arma V3 [paid link], troubleshoot common issues, explore customization options, and offer insights on optimizing its performance.

Tools Required

To effectively work on your Arma V3 rear shock, you will need the following tools:

• 5mm, 6mm, and 8mm Allen wrenches [paid link]
• Torque wrench [paid link] (up to 25 Nm)
• Shock pump
• Tuning spacer kit (if available)
• High-quality grease
• Rags and cleaning solution

Installation of the Arma V3 Rear Shock

Installing the Arma V3 rear shock is straightforward, but precision is crucial to ensure optimal performance. Follow these steps to install the shock onto your bike frame:

1. Prepare the Frame: Clean the mounting points on your bike frame where the shock will attach. Check for any debris or dirt, as these can affect the performance of the shock.
2. Install the Mounting Hardware: Insert the shock’s mounting hardware into the frame’s shock mounts. The Arma V3 typically uses standard eyelet or trunnion mount configurations, depending on your frame’s design. Ensure that the hardware is correctly aligned and that it fits snugly.
3. Attach the Shock: Position the shock in the mounting points, ensuring the eyelet or trunnion fitting matches the frame’s design. Use the appropriate fasteners and tighten them according to the manufacturer’s torque specifications (typically between 18-22 Nm).
4. Set Initial Air Pressure: Using a shock pump, set the air pressure according to your body weight. A rough starting point is to set the shock pressure at around 30% sag for cross-country riding, but this may vary based on personal preferences and terrain.
5. Check for Proper Fitment: Ensure that the shock sits evenly and securely in the mounts, with no excessive play or movement. Test the shock by compressing it manually, checking for smooth operation without binding or resistance.

Adjusting the Arma V3 Rear Shock

The Arma V3 features several key adjustments that can be made to fine-tune the shock’s performance. These adjustments include air pressure, rebound damping, compression damping, and high/low-speed compression. Here’s how to adjust each:

1. Air Pressure Adjustment

Air pressure directly affects the shock’s sag, which influences the ride feel and responsiveness. To adjust:

• Use a shock pump to increase or decrease the air pressure as needed. Start by setting the air pressure to about 30% of the shock’s total travel (check the shock’s manual for specific recommendations).
• Adjust air pressure based on your weight and the type of riding you plan to do. For example, lighter riders may need less air pressure, while heavier riders will need more to achieve the correct sag.

2. Rebound Damping

Rebound damping controls how quickly the shock returns to its original position after compression. If the rebound is too fast, the shock will feel “bouncy,” while too slow can cause it to feel sluggish.

• Turn the rebound knob (usually located at the bottom of the shock) to adjust. Turning the knob clockwise will slow the rebound, while counterclockwise will speed it up.
• Test the rebound by compressing the shock and observing how it returns. Adjust until you achieve a smooth, controlled return without excessive bounce.

3. Compression Damping

Compression damping controls the shock’s resistance to compression under load. There are typically two types of compression adjustments: low-speed and high-speed.

• Low-speed Compression: Adjust this setting to control how the shock responds to gradual inputs, like pedaling forces or slight bumps. Turn the low-speed compression knob (usually located on the top of the shock) to the desired setting.
• High-speed Compression: This setting governs how the shock responds to larger, more abrupt impacts, such as big drops or rocks. Adjust the high-speed compression knob (usually a separate knob on the opposite side of the shock) to fine-tune the shock’s response to fast hits.

4. Fine-Tuning for Terrain

If you’re riding technical trails, you may prefer more low-speed compression for better pedaling support and more high-speed compression for improved impact absorption. On smoother terrain, you might opt for less compression to maximize comfort and performance.

Common Setup Issues and Troubleshooting

While setting up the Arma V3, you may encounter some common issues. Here’s how to troubleshoot them:

1. Sag Not Achieving Proper Setting

If the sag is too high or too low, adjust the air pressure. If the shock still doesn’t behave as expected, check if the shock is over- or under-inflated and adjust accordingly. Additionally, ensure that the frame’s geometry allows for the proper travel range.

2. Shock Feeling Bouncy

Excessive rebound can cause the shock to feel bouncy. If this happens, adjust the rebound damping to a slower setting. Additionally, check that the shock isn’t suffering from excessive wear or damage, which could lead to poor performance.

3. Unusual Noises or Sticking

If the shock makes noise during operation or feels sticky, check for contamination, such as dirt or debris. Clean the shock thoroughly and apply fresh grease to the pivot points and mounting hardware. Inspect the seals to ensure they’re not damaged or worn out.

4. Air Leaks

If you notice a significant loss in air pressure, the shock may have an air leak. Inspect the air valve and seals, ensuring that the valve is properly closed and sealed. If the leak persists, contact a professional for further inspection.

Customization and Performance Optimization

To further customize your Arma V3 for enhanced performance, consider the following:

• Shock Spacers: Adding or removing spacers can modify the shock’s progression, altering how it responds during the final part of the compression stroke. This can help riders who prefer a more progressive feel or those seeking extra bottom-out protection.
• Spring Options: If the air spring doesn’t provide the feel you’re looking for, consider switching to a coil spring option, if compatible. Coil springs offer more consistent performance across a wider range of temperatures and conditions.

Fine-Tuning for Different Riding Styles

• For cross-country riding, you may want to dial in more low-speed compression for efficient pedaling and lighter settings for smoother terrain.
• For enduro or downhill riding, increase both low-speed and high-speed compression for better control through rougher terrain and faster descents.

Compatibility with Other Drivetrain Components

The Arma V3 rear shock is designed to work seamlessly with modern mountain bike frames, but it is essential to ensure compatibility with your bike’s drivetrain components. The shock itself does not directly interact with the drivetrain but may be impacted by frame geometry, rear triangle design, and suspension travel limits.

Check your frame’s specifications to ensure that the shock’s travel and mounting dimensions align with your bike. Additionally, ensure that your drivetrain components (e.g., chainring, cassette, derailleur) provide enough clearance around the shock.

Conclusion

With the right setup and attention to detail, the EXT Arma V3 rear shock can greatly enhance your bike’s performance, offering improved comfort, control, and responsiveness. Whether you’re adjusting air pressure, tuning the damping settings, or troubleshooting issues, fine-tuning this shock to your personal preferences will give you the best ride possible. By regularly maintaining your shock and making small adjustments as you gain more experience, you can unlock the full potential of your Arma V3 and enjoy a smoother, more responsive ride.