Start by working out what kind of rub it is
How the rub behaves points to the cause, so spend a minute looking before adjusting.
- Constant rub on one side: usually the brake is off-centre, or the wheel is not seated straight.
- Rub that comes and goes once per wheel turn: the rim or rotor is probably not true (slightly bent).
- Rub on both sides all the time: the pads may be too close, the cable too tight, or the brake is not releasing. See brakes that will not spring back.
- Rub that began after new pads: new pads are thicker and may need re-centring.
Lift the front wheel and spin it. Watch and listen for where contact happens.
Check the front wheel is seated
A wheel that is not fully in the fork dropouts can sit slightly off-centre and cause rub. Open the quick release or axle, make sure the wheel drops fully into the dropouts and is straight, then close it securely. A quick release lever should close with firm resistance. If your bike uses a thru-axle, follow the manufacturer’s tightening instructions. Re-check the rub afterwards, because this alone fixes many cases.
Rim brakes: centring
For V-brakes and many side-pull calipers, centring is done with spring tension or a centring screw.
- Look for a small screw on each brake arm (often Allen or Phillips).
- Identify which pad is closer to the rim.
- Turn the screw on that arm to move the pad away, or turn the other side’s screw to bring its pad closer. Use small turns and check after each.
- Squeeze the lever a few times and re-check how the pads sit.
If the screw has no effect, the brake may need its mounting bolt loosened and re-centred, or the pivots may be sticking. Make sure the pads hit the braking surface of the rim and not the tyre.
Disc brakes: re-centre the caliper
- Slightly loosen the two bolts that hold the caliper to the fork, just enough that the caliper can move side to side.
- Squeeze and hold the brake lever, which centres the caliper over the rotor.
- While holding the lever, tighten the bolts a little at a time, alternating between them, so the caliper does not shift.
- Release the lever, spin the wheel, and check for clearance on both sides.
Disc brake clearance is small by design, so a very faint sound can remain on some setups. A steady scrape is not normal and is worth chasing down.
Rub that comes and goes with each rotation
If the rub is rhythmic, the rim or rotor is likely not straight. On a disc rotor, look for the spot where the rotor gets closest to a pad. Small bends can be corrected with a proper rotor truing tool, though many riders have a shop do it. A rim that wobbles needs wheel truing, which is best left to a shop unless you have experience with spoke tension.
Rub after new pads
New pads are thicker than worn ones, so there is less clearance. Re-centre the caliper and check the pad position. On hydraulic brakes, pistons pushed in to fit new pads should move back out as you pump the lever. If the pads then drag, see brakes that will not spring back. Some squeak may also occur while new pads settle in, which is covered in how to stop squeaky bike brakes.
A loose or wobbly brake
If the brake itself moves, check that the mounting bolts are secure. Loose bolts can cause rub and are a safety issue. Tighten them to the torque listed on the component or in the manufacturer’s instructions. If the threads feel stripped or the bolt will not tighten, stop riding and get it checked.
Check before you ride
- The wheel spins freely with the brake released.
- The lever stops firmly before reaching the handlebar.
- Both pads contact the rim or rotor evenly.
- All bolts are secure.
If you also need to take up cable slack, the same principles are explained in how to adjust rear bike brakes.
FAQ
Is it normal for brake pads to rub after replacement?
It can happen, since new pads leave less clearance. Re-centre the brake and, on hydraulic discs, pump the lever so the pistons reset. Persistent rub is not normal.
How do I stop my disc brakes from rubbing?
Loosen the caliper bolts, squeeze the lever to centre the caliper, and re-tighten gradually. If the rub continues, check the wheel seating and rotor straightness.
How do I fix a loose front brake?
Check and tighten the mounting bolt to the recommended torque. If it keeps loosening or the threads are damaged, have it inspected.