Why Do My Mountain Bike Disc Brakes Squeal

Disc brakes are a great addition to any mountain bike. They provide much better stopping power and modulation than rim brakes, but they can be noisy.

The noise is caused by the pads and brake rotor rubbing against each other. This rubbing creates friction that generates heat, which in turn causes the metal to expand and contract as it cools down. This expansion and contraction creates a squealing sound that can be annoying when you’re trying to stop quickly or ride at low speeds.

How do I stop my mountain bike disc brakes from squeaking?

“Cleaning your rotors or wheel rims regularly with a specific (oil-free) disc brake degreaser is a good way to avoid squealing brakes. Cleaning your pads too can help quieten things down – you can try some sandpaper or grinding the pads – but if the grease has soaked through the pad, you might need to replace them.^[1]

What causes squeaky bike disc brakes?

The most common issue causing brake squeal is contamination or glazing of the brake pads, or rotor. Contaminants (such as oil from our fingers when you accidentally touch the pads or rotor) cause the pads to lose grip on the rotor, which can cause vibrations leading to squealing.^[2]

Can I use wd40 on my bike disc brakes?

Well, you’re in luck because WD-40 has formulated the perfect solution that can dissolve the grime and dirt stuck in your brakes for easy removal. Smart, right? WD-40 BIKE® Degreaser has been specially formulated for quick and easy removal of dirt, mud, and grime from the brake disc rotors.^[3]

How do I fix squeaky disc brakes?

Sometimes, brake pads vibrate because they aren’t securely in place. You can fix this by installing a set of shims to eliminate vibrations, which should make any squealing noise go away. Shims ensure brake pads are fastened tightly to the brake calipers and typically use a layer of rubber to reduce vibrations.^[4]

Are new bike brakes supposed to squeak?

Firstly, if you have a new bike or new pads/rotors, then it is very normal for them to squeak. It takes some time for the pads to work together, in what is called “bedding in”. This is where the act of braking starts to release debris onto the micro surfaces of the pads and rotors.^[5]

Why do brakes squeal at low speeds?

As described in some owner’s manuals, the squealing noise is caused by high-frequency vibration of the brake pads against the rotating disc. Vibration is the unavoidable result of friction generated by the pads as the caliper clamps them against the rotating disc.^[6]

How do I clean my bike disc brakes?

If you have disc brakes, try to keep soap away from the rotors and brake pads. You can use a specific rotor cleaner or rubbing alcohol to clean the rotors. Finish by scrubbing the chainstays, chain rings, cranks and cogs.^[7]

Can I spray WD40 on my brakes to stop squeaking?

Avoid Using WD40 to Lubricate Brakes. WD40 is a general lubricant appropriate for home use. However, the petroleum distillates it contains may attack the rubber car brakes are made of. That being said, in all likelihood a light spray of WD40 will not cause serious damage.^[8]

Can you spray WD40 on brakes?

WD-40 Specialist Automotive Brake and Parts Cleaner is safe to use on clutch and brake assemblies, brake discs, callipers, brake drums, brake pads and brake linings.^[9]

Where do you spray disc brakes quiet?

Remove brake pads and clean with Brakleen® Brake Parts Cleaner. Shake well and spray evenly onto the steel back of each outboard and inboard pad. Do not apply to lining, rotors, side of pad that contacts rotors, or any moving parts. Allow to set for 10 minutes and then reassemble brakes.^[10]

Why are my brakes squealing with new brakes?

As mentioned, new pads are typically abrasive and are sometimes coated with protective elements that can cause noise. After some wear, sometimes referred to as a “bedding process,” that brake pad squeak will go away.^[11]

Why do my Shimano disc brakes squeal?

Brake Rub. If you have a squeak, squeal or pinging noise that occurs while you are riding at regular intervals, it is usually a caliper alignment issue or a bent rotor that is causing your brake pads to rub as you ride. Check to make sure this is the problem by lifting your wheel off the ground and giving it a spin.^[12]