Brakes are the component where small adjustments matter most. The goal in every system is consistent, predictable stopping: pads that meet the braking surface squarely, a lever that firms up well before it reaches the handlebar, and a wheel that spins without constant rub. The steps differ between rim and disc brakes, but the targets are the same.
Read the symptoms first
| What you notice | Likely cause | Where to look |
|---|---|---|
| Lever reaches the bar | Worn pads, cable stretch, or low hydraulic fluid | Pad thickness, cable tension, lever feel |
| Steady rub when spinning | Off-centre caliper or unseated wheel | Caliper position, axle / quick-release |
| Squeal or weak bite | Contaminated or glazed pads and surface | Pad face, rotor or rim track |
Rim brakes
Pad alignment
Rim brake pads should strike the braking track of the rim squarely, not the tire and not below the rim. Many pads can be toed in slightly so the leading edge contacts first, which reduces squeal. Keep pads clear of the tire sidewall, since contact there can cut the casing.
Cable tension and centring
As pads wear, the lever travels further. Adjusting the barrel adjuster or resetting the cable restores lever feel. Centring screws on the caliper arms equalise the gap so neither pad rubs when the wheel spins freely.
Disc brakes
Centring the caliper
A common cause of rub is a caliper that is not centred over the rotor. Loosening the mounting bolts, squeezing the lever to let the caliper self-align, then retightening while held is a standard approach for many designs.
Keep them clean
Disc pads and rotors are sensitive to oil and grease. Chain lubricant, degreaser overspray or handling the rotor with bare, oily hands can dramatically reduce braking power. Keep lubricants well away from braking surfaces.
Bedding in new pads
New pads and rotors usually need a bedding-in process so the pad material transfers evenly to the braking surface. This typically involves a series of progressively firmer stops from moderate speed, following the manufacturer's instructions for the specific pads.
When to stop and get help
Brakes are safety-critical. If the lever stays spongy after adjustment on a hydraulic system, if pads are worn to their limit, or if you are unsure whether the system is safe, have it checked by a qualified bicycle mechanic before riding.