The Arch MK4 [paid link] wheels from Stan’s NoTubes are known for their durability, lightweight design, and superior performance. However, like any precision component, over time, the bearings in the hub may wear out due to exposure to moisture, dust, and other elements. Replacing these bearings ensures smooth rotation and optimal performance. This guide will walk you through the process of replacing the bearings in your Arch MK4 [paid link] wheels, offering tips for installation, adjustment, and maintenance to keep your wheels in top condition.

Tools Required

• 10mm or 15mm wrench (depending on the hub’s axle size)
• 2.5mm or 3mm hex wrench
• Bearing puller tool
• Bearing press [paid link] tool (optional)
• Grease (preferably a bike-specific bearing grease)
• Clean rag
• Small flathead screwdriver or pick tool

Removing the Hub from the Wheel

Before you can replace the bearings, the first step is to remove the hub from the wheel. Here’s how to do it:

1. Remove the wheel from the bike: Start by detaching the wheel from the bike frame or fork.
2. Remove the end caps: Use a 10mm or 15mm wrench (depending on your specific axle size) to remove the end caps from both sides of the hub.
3. Take off the axle: Once the end caps are removed, use the appropriate tool to unscrew the axle from the hub body. Depending on your hub configuration, the axle might either slide out easily or require additional components to be removed.
4. Remove the freehub body (if applicable): In some cases, you may need to remove the freehub body by gently prying it off with a small flathead screwdriver. Be careful not to damage the freehub body during this process.

Removing the Old Bearings

Once the hub is disassembled, you can access the bearings. The next step is to carefully remove the worn-out bearings.

1. Locate the bearings: The Arch MK4 wheels typically have two main bearings in the hub: one on each side of the axle.
2. Remove the seals: Gently remove the rubber seals covering the bearings. You can use a small flathead screwdriver or pick tool to lift the seals off without damaging them.
3. Use a bearing puller: To remove the bearings, use a bearing puller tool. Place the puller around the bearing and gradually tighten it to pull the bearing out of the hub shell. Repeat this process for both bearings.
4. Clean the hub: Once the bearings are removed, clean the inside of the hub shell using a rag to remove any old grease or debris.

Installing the New Bearings

Now that the old bearings are removed, it’s time to install the new ones.

1. Prepare the new bearings: Before installing the new bearings, apply a thin layer of high-quality bearing grease to both the inner and outer races of the bearings. This will ensure smooth operation and protect the bearings from wear.
2. Press the new bearings into place: Using a bearing press [paid link] tool, carefully press the new bearings into the hub shell. Make sure they are seated properly and are not tilted at an angle. If you do not have a bearing press tool, you can use a similar-sized tool with a soft mallet to gently tap the bearings into place.
3. Reinstall the seals: Once the bearings are in place, reinstall the rubber seals on both sides of the hub to protect the bearings from dirt and moisture.

Reassembling the Hub

After installing the new bearings, you can reassemble the hub.

1. Reinstall the freehub body: If you removed the freehub body earlier, carefully slide it back onto the hub. Make sure it engages properly with the pawls inside.
2. Insert the axle: Slide the axle back into the hub shell and make sure it fits snugly.
3. Reinstall the end caps: Once the axle is in place, reinstall the end caps on both sides of the hub. Tighten them securely, but be cautious not to overtighten and cause damage.

Final Adjustments and Testing

With the hub fully reassembled, it’s time to check everything for proper function.

1. Spin the wheel: Rotate the wheel by hand to ensure that the bearings are working smoothly. The hub should rotate freely without any resistance or grinding noises.
2. Check for play: Hold the wheel at the ends and try to wiggle it to check for any side-to-side play. If there’s any movement, the bearings may not have been installed properly or might need further adjustment.
3. Install the wheel on the bike: Reinstall the wheel onto your bike frame or fork. Tighten the quick release or through-axle properly to secure the wheel.

Troubleshooting Common Set-Up Issues

After replacing the bearings in your Arch MK4 wheels, you might encounter a few issues. Here’s how to address some common problems:

• Grinding or rough rotation: If the wheel still feels rough after installing new bearings, the bearings might not have been seated properly or there could be debris trapped inside the hub. Disassemble the hub again and inspect the bearings and the hub shell.
• Excessive play: If there’s noticeable side-to-side play in the hub, check the axle installation. Ensure it’s tight and correctly positioned. If the problem persists, the bearings may not be correctly pressed into place.
• Hub noise: While some noise is normal, excessive noise from the hub after bearing replacement could indicate that the freehub body is not fully engaged or that there’s an issue with the pawls inside. Check the freehub body and pawls for any damage or misalignment.

Customization and Optimization

To further optimize the performance of your Arch MK4 wheels, consider the following adjustments:

• Lubrication: Use high-quality bearing grease to ensure that the bearings run smoothly. Avoid using too much grease, as it can attract dirt and debris.
• Hub upgrades: Some riders prefer to upgrade the freehub body to a more advanced model or choose ceramic bearings for enhanced performance and longevity.
• Sealing: Make sure the rubber seals are properly installed and in good condition to prevent water and dirt from entering the bearings.

Compatibility with Other Drivetrain Components

The Arch MK4 wheels are compatible with a wide range of drivetrain components, but it’s important to ensure that your hub and freehub body are compatible with your cassette and axle type. The wheels support both quick release and through-axle configurations, but you may need specific end caps for your bike’s axle type. Always check your component specifications before beginning the bearing replacement to ensure proper fit and function.