Disc brakes have revolutionised modern bikes, offering unparalleled stopping power in all weather conditions. Today, disc brakes are found on a wide range of bikes, from gravel adventurers to high-speed road racers, providing these same advantages. However, even the finest brakes can develop annoying squeaks without proper maintenance.
When your disc brakes start making loud, irritating noises, several common issues might be at fault. Here's a breakdown of the most frequent culprits and how to address them. But first, let's put that straight: NEVER EVER PUT OIL, WD40, OR SPRAY ANY LUBRICANT ONTO YOUR DISC OR YOUR PADS. No exception. We explain why in more details later in this post (see point #2).
Annoying noise #1: Brake Rub
A periodic pinging noise during rides typically indicates a misalignment of the caliper or a bent rotor causing the brake pads to rub as you pedal. To confirm this issue, lift your wheel off the ground and give it a spin. If the wheel doesn't rotate freely and comes to a halt, you're dealing with brake rub!
Solution: Ensure your wheel is properly seated in the fork or chainstay dropouts, especially if using a quick-release skewer that doesn't thread into the frame. Improper axle installation can misalign both the wheel and rotor. If you are not confident or are not sure what you are doing, go to your Local Bike Shop
Annoying noise #2: Contamination
Consistent, loud squealing when applying the brakes usually points to contamination. Brake pads, being porous, readily absorb grease and oils, resulting in reduced effectiveness and squealing. Contaminants like chain lube, bike polish, degreaser, or brake fluid can transfer to the rotor and contaminate the pads. Even touching the rotor or pads with oily hands can lead to contamination!
Solution: If you suspect oil or grease on your brake rotors, immediately clean them with a rag and isopropyl alcohol. If the pads are already contaminated, there's still hope! Try sanding down the outer layer of the pads with fine-grained sandpaper. However, if your pads are soaked in chain lube, it's best to replace them.
Annoying noise #3: Glazed brake pads
New rotors or brake pads need proper breaking in to function optimally. Skipping this process can lead to overheating, causing the pads to "glaze" over and produce a nasty squeak when braking.
Solution: Always break in your brake pads by lightly squeezing the brakes while pedaling around on pavement before hitting the trail. Repeat this process about ten times until you feel the brakes becoming more powerful. This technique evenly transfers some brake pad material onto the rotor. If you've already glazed your pads, remove them from the caliper and use sandpaper to scuff up the surface before properly breaking them in.
Annoying noise #4: Water and heat
Water and heat can also contribute to brake noise. Riding through puddles or streams may temporarily cause squealing, while consistent braking, especially during downhill rides, can lead to howling brakes that persist even after cooling down.
Solution: If your brakes overheat, the rotor may become discoloured and require replacement. Consistent overheating indicates a need for a larger brake rotor, as larger rotors dissipate heat more efficiently, resulting in quieter braking.
