DNM AO-8RC MTB Rear Shock Instruction Manual

1. Product Overview

The DNM AO-8RC is an air suspension rear shock designed for various mountain biking styles including XC (Cross Country), TRAIL, AM (All Mountain), FR (Freeride), and DH (Downhill). It features adjustable rebound, a three-step lockout system, and air pressure adjustment to fine-tune your ride experience.

2. Specifications

Available Sizes and Weights

3. Setup and Installation

3.1 Bushing Selection and Installation

Each shock comes with two 24mm bushings by default. Ensure you select the correct bushing length for your bike frame. If different lengths are required, please acquire them separately.

3.2 Mounting the Shock

1. Ensure the correct bushings are installed in the shock eyelets.
2. Align the shock with the mounting points on your bicycle frame.
3. Insert the mounting bolts through the frame and shock eyelets.
4. Tighten the mounting bolts to your bicycle manufacturer's specified torque settings. Do not overtighten.
5. Verify that the shock moves freely through its travel without binding.

3.3 Initial Air Pressure Adjustment

The AO-8RC is an air shock and requires proper air pressure for optimal performance based on rider weight and riding style. Use a high-pressure shock pump (not included) to adjust the air pressure.

• Locate the air valve mouth on the shock.
• Attach a high-pressure shock pump.
• Inflate the shock to an initial pressure. A common starting point is 1 PSI per pound of rider weight, but this may vary.
• The maximum air pressure for this shock is 275 psi. Do NOT exceed this limit.
• Remove the pump carefully to avoid air loss.

4. Operating the Shock

The DNM AO-8RC features three main adjustments to customize your ride: Rebound, Three-step Lockout, and Air Pressure.

4.1 Rebound Adjustment

The red knob controls the rebound damping, which dictates how quickly the shock extends after compression.

• Turn the red knob towards the '+' symbol to slow down the rebound (slower extension).
• Turn the red knob towards the '-' symbol to speed up the rebound (faster extension).
• Adjust rebound based on terrain and rider preference. Slower rebound is generally preferred for larger bumps and jumps, while faster rebound is better for quick, successive bumps.

4.2 Three-step Lockout

The blue lever controls the shock's compression damping, offering three distinct settings:

• LOCK: This position turns off the shock absorber, providing a firm platform suitable for climbing or smooth terrain.
• MIDDLE: This position offers half suspension, providing some damping while still maintaining efficiency. Ideal for varied terrain where full lockout is too harsh but full suspension is not needed.
• OPEN: This position fully opens the shock absorber, allowing for maximum travel and plushness, suitable for technical descents and rough trails.

4.3 Air Pressure Adjustment

As mentioned in the setup, air pressure is crucial for sag and bottom-out resistance. Regularly check and adjust air pressure using a high-pressure shock pump to match your riding conditions and weight. Refer to Section 3.3 for details.

5. Maintenance

Proper maintenance ensures the longevity and optimal performance of your DNM AO-8RC rear shock.

• Cleaning: After each ride, especially in dirty or wet conditions, clean the shock body and shaft with mild soap and water. Wipe dry with a soft cloth. Avoid high-pressure washers directly on seals.
• Inspection: Regularly inspect the damper shaft for scratches or damage. Check all bolts for proper tightness and ensure no play in the bushings. Look for any signs of oil leakage around the seals.
• Air Pressure Check: Check the air pressure before every ride. Air shocks can slowly lose pressure over time.
• Seal Service: Over time, seals will wear out. If you notice excessive oil leakage, reduced performance, or frequent air loss, it may be time for a seal service. It is recommended to have this performed by a qualified bicycle mechanic.

6. Troubleshooting

6.1 Loss of Air Pressure

• Symptom: Shock feels too soft, bottoms out easily, or loses sag.
• Possible Cause: Leaking air valve or worn air seals.
• Solution: Check the air valve core for tightness. Re-inflate to correct pressure. If pressure loss persists, inspect seals for damage or consider a seal service.

6.2 Improper Damping

• Symptom: Shock feels too bouncy (pogo stick effect) or too slow to return.
• Possible Cause: Incorrect rebound setting.
• Solution: Adjust the red rebound knob. If too bouncy, slow down rebound (+). If too slow, speed up rebound (-).

6.3 Shock Not Locking Out or Locking Out Partially

• Symptom: Blue lockout lever has no effect or only partial effect.
• Possible Cause: Internal damping issue or low air pressure.
• Solution: Check air pressure and adjust if necessary. If the issue persists, internal service may be required.

6.4 Unusual Noises (Creaking, Squeaking)

• Symptom: Noise coming from the shock during compression or extension.
• Possible Cause: Loose mounting bolts, dry bushings, or internal issue.
• Solution: Check and re-torque mounting bolts. Inspect bushings for wear and lubricate if necessary. If noise persists, consult a mechanic.

7. User Tips

• Set Sag Correctly: Proper sag (the amount the suspension compresses under your weight) is crucial for performance. Aim for 25-30% sag for trail riding. Use the O-ring on the shaft to measure.
• Experiment with Settings: Don't be afraid to experiment with rebound and air pressure settings to find what works best for your riding style and local trails. Make small adjustments and test them.
• Clean Regularly: Keeping the shock clean, especially the shaft and seals, will prevent dirt and debris from entering the system and prolong the life of your shock.
• Consider a Shock Pump: A high-pressure shock pump is an essential tool for any rider with an air shock.

8. Warranty and Support

For warranty claims, technical support, or service inquiries, please contact the seller or manufacturer directly. Keep your proof of purchase for any warranty-related issues.