How To Mount 160mm Disc Rotor to Replace 140mm on Road or Gravel Bike

Mounting a larger disc rotor on a road or gravel bike is a common upgrade for improving braking performance, especially for heavier riders or in challenging terrains where more braking power is beneficial. Here’s a step-by-step guide on how to mount a 160mm disc rotor to replace a 140mm rotor:

What You Need (links are affiliated):
New 160mm disc rotor (6 bolt or center mount depending on your current setup) https://amzn.to/4aWZjzm
Correct disc brake caliper adapter (140mm to 160mm) https://amzn.to/3UkyCPA
Allen wrenches (typically 4mm and 5mm) https://amzn.to/3xJDy80
Torx T25 screwdriver https://amzn.to/49GpZTZ
Torque wrench https://amzn.to/3xRJQ5e
Thread locker (optional but recommended) https://amzn.to/3xOQMjC

1. Purchase the Correct Adapter
Please ensure you buy the right adapter for your bike frame and fork. Adapters are specific to the mounting type (post mount or flat mount) and the size increase you intend (from 140mm to 160mm in your case).

2. Remove the Wheel
Loosen the quick-release or thru-axle and remove the wheel from your bike. This will allow you to access the brake rotor and caliper.

3. Remove the Existing Rotor
Use an Allen wrench to remove the bolts holding the 140mm rotor to the wheel hub. Set the old rotor aside and clean the hub surface if necessary.

4. Install the New Rotor
Place the 160mm rotor on the hub, aligning the bolt holes. To prevent the rotor bolts from loosening, apply a small amount of thread locker. Tighten the bolts in a star pattern to ensure even pressure. The typical torque specification is around 6 Nm, but check the rotor manufacturer’s recommendation.

5. Adjust the Brake Caliper
With the larger rotor, you must reposition the brake caliper to accommodate the increased diameter. Attach the adapter to the fork or frame's brake mount using the original bolts (apply thread locker here too). Then, mount the caliper onto the adapter using the bolts provided with the adapter. Ensure all bolts are tightened to the manufacturer's specified torque, which is usually around 6-8 Nm for caliper bolts.

6. Reinstall the Wheel
Put the wheel back into the fork or frame. Ensure it is properly seated and the thru-axle or quick release is securely fastened.

7. Check Brake Alignment
Spin the wheel to check for any rotor rubbing against the brake pads. If you hear rubbing or see the rotor touching one pad, you may need to adjust the caliper. Loosen the caliper bolts slightly, spin the wheel, and then squeeze the brake lever to center the caliper over the rotor. Tighten the bolts while holding the brake lever.

8. Test Ride
Conduct a cautious test ride in a safe area to ensure everything works correctly. Check for any unusual noises or vibrations and confirm the brake's responsiveness.

Additional Tips
Brake Bed-In Process: After installing new rotors or pads, it’s important to bed them in. This involves several sharp stops from a moderate speed to allow the pad material to coat the rotor surface evenly, improving braking performance.
Safety Check: Always double-check each bolt for proper torque to avoid any mechanical failures during rides.

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