How To Fix Brake Rub On Disc Breaks Mountain Bike

How to adapt a bike'southward hydraulic disc brakes and prevent restriction rub

(Prototype credit: Graham Cottingham)

If everything is gear up upwards correctly on even the best mountain bicycle brakes, a well-tuned fix of brakes should not make any noise. However, one of the most common noises that might come up from your brakes is a metallic scraping audio. That's the audio of a disc brake rotor rubbing confronting the pads. You tin tell that the rotor is rubbing if you spin the wheel and it slows downward drastically without you engaging the brake lever. You lot may be able to actually experience the brake rub when you ride, depending on how severe information technology is.

Diagnosing the noise

Adjusting the postion of your disc brake is a simple process, but allow's first review how your bike'south hydraulic disc brake system works. The brake lever configuration on the handlebars has a reservoir for the hydraulic brake fluid that travels through the brake lines. When you engage the lever, the fluid pushes through the lines to the caliper.

The caliper houses pistons and restriction pads. The fluid pushes the pistons, which in turn pushes the brake pads together. The pads squeeze the rotor, which is how you slow downwards.

Firstly you need to determine what is causing your rotor to rub on the pads. Spin the bicycle and look at the gap inside the brake caliper betwixt pad and rotor. If you can meet the rotor is constantly rubbing, so yous will demand to realign the caliper. If the deejay has a distinctive bend or wobble that catches as the wheel spins, then you'll need to straighten the disk.

A view of a mountain bike brake caliper and brake pads — The gap between the rotor and disc is small and then any misalignment can cause rubbing (Epitome credit: Rich Owen)

Realign the caliper

To realign the caliper and end the brake from rubbing, loosen the 2 caliper mounting bolts, and then firmly pull the restriction lever. Since the bolts are loose, this will center the caliper. While holding the lever in tight, re-tighten the mounting bolts.

Give the wheel a spin to see if the brake however rubs. If it is, repeat the loosen-retighten process again, or you can fine-tune the caliper alignment by loosening ane commodities at a time. Spin the wheel and gently accommodate the caliper by hand (button the caliper in the direction that volition eliminate rubbing), and retighten the bolt.

If there is still rubbing after completing this process, in that location may be a bigger result. Make sure the rotor's mounting bolts are properly tightened and that in that location is no play in the cycle's hub. If either of these is loose, that may contribute to rubbing.

A mountain bike brake caliper being adjusted — Tighten the caliper mounting bolts while keeping the brake lever compressed (Prototype credit: Rich Owen)

Straightening a rotor

Deejay rotors are designed to exist very strong in a vertical plane, however even calorie-free impacts horizontally tin can bend a rotor enough to rub. Crashing is often the primary cause although impacts from trail debris or a merely bump when the cycle is leaned exterior a buffet or in a wheel rack will practise it.

A rotor truing tool will make the job a lot easier, an adjustable spanner works well too and if y'all are in a squeeze a rotor tin be carefully bent back past manus. Whether you use a tool or not, the almost of import affair to call back when dealing with a rotors is that whatever touches the braking surface should be as clean equally possible.

Truing a rotor is unproblematic case of locating the indicate that rubs and determining the management information technology needs to exist trued to stop information technology rubbing. Once identified, gently bend the rotor back. Repeat this process until the rotor no longer rubs. Repeated gentle bends should cease y'all bending the rotor as well far in the opposite direction and creating more problems.

If it proves impossible to true your rotor or you've completely spangled bit in a crash, you lot'll need a buy a replacement. If it's a more bones version, have a await at our guide to the best mountain cycle disc rotors and consider upgrading to a more efficient model.

And if you're having bug with your gears, you might wish to take a look at our guide to adjusting mountain bicycle shifting.

Ryan Simonovich has been riding and racing for nearly a decade. He got his start as a cross-country mountain cycle racer in California, where he cultivated his love for riding all types of bikes. Ryan somewhen gravitated toward enduro and downhill racing but has as well been found in the occasional road and cyclo-cross events. Today, he regularly rides the trails of Durango, Colorado, and is aiming to make a career out of chronicling the sport of cycling.

Rides: Santa Cruz Hightower, Specialized Tarmac SL4