Troubleshooting › Brakes

Brake rubs or scrapes when the wheel spins: causes and fixes

Lift the wheel and spin it. A rub at one spot is a bent rotor or wobbly wheel; a constant rub is alignment.

Check it on your own bike

1. Caliper not centered · Most likely

   Disc: loosen the caliper bolts, squeeze the lever and tighten while holding it (on single-piston cable discs, first dial the inner pad close to the rotor). Rim brakes: even out the spring tension screws.

   Fix: Center and adjust mechanical disc brake · Center a hydraulic caliper · Center and adjust a road caliper

2. Wheel not seated straight · Most likely

   Open the quick release or axle, let the bike's weight seat the wheel, and close it again.

   Fix: Use a quick release properly · Install a thru-axle wheel · Remove and refit a bolt-on wheel

3. Bent rotor · Sometimes

   Watch the gap through the caliper as you spin: if the rotor moves side to side, true it.

   Fix: True a bent rotor

4. Wheel out of true · Sometimes

   Rim brakes: watch the rim pass the pads. A wobble rubs at one spot.

   Fix: True a wheel (lateral wobble)

5. Sticky hydraulic pistons · Less likely

   Hydraulic: if one pad stays out, push the pistons back with a pad spreader and re-center.

   Fix: Center a hydraulic caliper · Replace hydraulic disc pads