When it comes to improving your bike’s performance, upgrading your rear suspension is one of the most impactful changes you can make. The DVO Topaz MX [paid link] Rear Shock is designed to deliver exceptional comfort, control, and efficiency, allowing riders to push their limits on technical trails. In this guide, we’ll walk you through everything you need to know about installing, adjusting, maintaining, and optimizing the Topaz MX [paid link] to get the best out of your ride.
Tools Required
- 5mm and 8mm Allen wrenches [paid link]
- Torque wrench [paid link]
- Suspension pump
- 10mm socket wrench
- Adjustable spanner
- Shock oil (if performing a full service)
- Cleaning supplies (cloth, degreaser)
- Grease for shock mounting bolts
Installing the Topaz MX Rear Shock
Step 1: Remove the Existing Shock
Before installing the Topaz MX, ensure that your bike is secure and that the rear wheel is removed if necessary. Use the appropriate Allen wrenches [paid link] to unscrew the shock mounting bolts, being careful not to damage any parts. Clean the area around the shock mounts to ensure a clean installation surface.
Step 2: Prepare the Topaz MX Shock
Before mounting the new shock, inspect the Topaz MX and ensure it’s ready for installation. Confirm the correct spring rate is in place, based on your weight and riding style. If needed, adjust the air pressure or change the volume spacers to suit your preferences. You’ll need a suspension pump for accurate air pressure adjustments.
Step 3: Mount the Shock
Align the eyelet of the Topaz MX with the shock mount on your frame. Carefully insert the shock and hand-tighten the mounting bolts. Use a torque wrench [paid link] to tighten the bolts to the manufacturer’s recommended settings (usually around 150-175 inch-pounds, depending on your bike). Ensure the shock is aligned properly and that the mounting hardware is not overtightened.
Step 4: Check for Proper Function
Before reassembling your bike, check for any binding or rubbing from the shock. Compress the shock manually to verify that the travel is smooth and unobstructed. Once everything is secure, you can reinstall the rear wheel if needed and proceed to adjust the settings.
Adjusting the Topaz MX Rear Shock
Setting Air Pressure
The Topaz MX features a high-performance air spring system that allows riders to adjust the shock pressure for optimal comfort and support. Start by setting the air pressure based on your weight. Use a suspension pump to inflate the shock to the recommended pressure, which is typically between 200 to 300 psi, depending on the rider’s weight.
After setting the air pressure, perform a basic sag check. Sit on the bike and observe how much the shock compresses under your weight. The ideal sag should be around 25-30% of the shock’s total travel. Adjust the air pressure accordingly to fine-tune the sag.
Adjusting Rebound Damping
The rebound adjustment on the Topaz MX allows you to control how quickly the shock returns after compression. If the rebound is too fast, the bike will feel “bouncy,” and if it’s too slow, it could lead to a harsh ride. Start by setting the rebound to the middle of the adjustment range, then ride and test how the bike handles. Fine-tune the rebound by turning the knob to your preference—turn it clockwise to slow it down and counterclockwise to speed it up.
Adjusting Compression Damping
The Topaz MX features both low-speed and high-speed compression damping adjustments. Low-speed compression primarily affects the shock’s response to slow inputs, like pedaling or small bumps, while high-speed compression affects the shock’s behavior over bigger hits and impacts.
Start with the low-speed compression adjustment at the middle setting and adjust based on how the bike handles smaller bumps and terrain. For high-speed compression, begin with a neutral setting and make adjustments depending on the roughness of the trail. Tighter settings (clockwise) will provide more support on aggressive trails, while looser settings (counterclockwise) offer a more plush ride.
Troubleshooting Common Set-Up Issues
Excessive Sag
If your Topaz MX is sagging too much, it could be due to insufficient air pressure. Increase the air pressure by 5-10 psi and check the sag again. If the sag remains excessive, ensure you are using the correct spring rate for your weight and riding style. Also, check for any leaks in the shock’s seals that might cause air loss.
Too Harsh or Too Soft a Ride
If the ride feels too harsh, try decreasing the air pressure slightly or loosening the compression settings. If the ride feels too soft, increasing the air pressure or tightening the compression settings might provide the necessary support.
Rebound Issues
If the shock is not returning quickly enough, it may be a sign of too much rebound damping. Turn the rebound knob counterclockwise to speed up the return. If the shock is bouncing or returning too quickly, increase the rebound damping by turning the knob clockwise.
Maintaining the Topaz MX Rear Shock
Regular Cleaning
Cleaning your shock after each ride is essential to maintaining its performance. Use a clean cloth and degreaser to wipe off any dirt, debris, and oil from the shock body. Avoid using harsh chemicals, as they can damage the shock’s seals.
Full Service
While the Topaz MX is designed to require minimal maintenance, a full service is recommended every 50-100 hours of riding. This service includes disassembling the shock, cleaning all internal components, and replacing the shock oil. A professional suspension technician can assist with this process, or you can follow the manufacturer’s guidelines to perform the service yourself.
Checking for Leaks
Periodically inspect your shock for signs of oil leaks, especially around the seals. If you notice any leakage, it’s best to have the shock serviced or rebuilt by a certified technician. This will help avoid compromising the shock’s performance and longevity.
Customization and Optimization for Better Performance
The Topaz MX offers plenty of customization options to tailor the shock to your specific needs. In addition to adjusting air pressure, rebound, and compression settings, you can experiment with different volume spacers to change the air spring curve. Adding or removing volume spacers alters the progression of the shock’s travel, making it more linear or more progressive. This customization helps you dial in the performance for your riding style and terrain.
Fine-Tuning for Different Terrain
- For smoother trails: Reduce the air pressure slightly for a more plush, forgiving ride. Use lighter compression settings to maintain control without sacrificing comfort.
- For aggressive trails: Increase air pressure to prevent bottoming out, and tighten the compression settings to provide more support over rough terrain.
Comparison with Similar Models
While the Topaz MX is an excellent choice for aggressive riders and enduro enthusiasts, there are other rear shocks on the market worth considering. The Fox DHX2 and RockShox Super Deluxe are two other popular choices in the same performance category.
The DVO Topaz MX is known for its superior control over both low- and high-speed compression, giving riders a more customizable ride compared to the Fox DHX2, which is often favored for its simplicity and ease of use. The RockShox Super Deluxe offers similar performance but may require more frequent maintenance due to its air spring design.
When choosing between these models, consider the type of riding you do most often, the level of adjustability you need, and the maintenance schedule you’re comfortable with.
Understanding Compatibility with Other Drivetrain Components
The Topaz MX is designed to be compatible with most modern mountain bike frames. However, it’s important to ensure that the shock’s dimensions match your frame’s specifications. Measure the eye-to-eye length and stroke of your current shock, and ensure that the Topaz MX is available in the corresponding sizes.
Additionally, the shock’s performance will work best when paired with other high-quality drivetrain components. Ensure that your bike’s linkage, frame, and other suspension components are in good condition and provide optimal performance when paired with the Topaz MX.