Favoritebikes Help Center

How to Fix and True a Bent Disc Brake Rotor

A bent disc brake rotor can cause frustrating rubbing and squealing, reduce braking power, and even be dangerous. Fortunately, you can fix a slightly bent rotor at home with some basic tools. Here's how:

Tools You'll Need:

  • Rotor truing tool (optional, but recommended for precision)
  • Adjustable wrench (crescent wrench) or large pliers
  • Clean rag or paper towel

Step-by-Step Guide:

  1. Assess the Damage: Spin the wheel slowly and observe the rotor through the brake caliper. Identify where the rotor is bending away from the caliper.

  2. Prepare the Tool: If you're using an adjustable wrench or pliers, wrap the jaws with a clean rag or paper towel to protect the rotor from scratches. If using a rotor truing tool, select the appropriate slot for the rotor's thickness.

  3. Apply Gentle Pressure: Gently apply pressure to the bent section of the rotor, pushing it back toward the center. Start with small adjustments and check your progress frequently.

  4. Check Alignment: Spin the wheel and observe the rotor again. If it's still rubbing, repeat the process until the rotor spins freely without making contact with the brake pads.

  5. Fine-Tune: If you're using a truing tool, you can make smaller adjustments to get the rotor perfectly straight. If using a wrench or pliers, be careful not to overcorrect and bend the rotor in the opposite direction.

Important Tips:

  • Work slowly and patiently. It's better to make multiple small adjustments than one large one.
  • Be careful not to overtighten the wrench or pliers, as you could damage the rotor.
  • If the rotor is severely bent, or if you're uncomfortable with the process, take your bike to a professional mechanic.

When to Replace the Rotor:

If the rotor is cracked, significantly warped, or cannot be trued, it's time for a replacement.

Remember: Truing a rotor is a temporary fix. To prevent the issue from recurring, try to avoid impacts or crashes that could bend the rotor in the first place.