Bike Disc Brake Pad Replacement

If your brakes are squeaky or not performing very well you may need to replace the pads. In this blog we are going to look at bike disc brake pad replacement.

Before you jump on the task, watch our video on how to stop bicycle disc brakes from squeaking as just replacing the pads may not solve the problem.

 A bike disc brake pad consists of braking material and a metal plate that helps to dissipate the heat and make the pad more rigid.

Three types of brake surfaces

Organic

These are made out of non-metallic fibres such as rubber, glass, Kevlar™, and are carbon bonded with resin. 

They are the cheapest option, providing sharp braking. However, they are the compound that wears the most quickly and they lose power when used constantly, such as downhilling, as they fade in higher temperatures. “Brake fade” describes the action of the brakes no longer stopping as well as they should. It happens when the pads are no longer able to create the friction needed to stop your bike quickly.

Some disc rotors are designed solely for organic pads. Check our article here or watch this video to find out more about disc rotors

Sintered

These are made out of metal particles combined together in a pressure and heating process.

They are longer lasting and work better than organic pads in steep descents when continuous braking is crucial. However, they are more expensive and not as sharp in normal riding conditions.

Semi-metallic

The best and the worst of both worlds. They are a mix of organic and metal fibres.

They wear more slowly than organic pads and provide sharper braking than sintered in everyday riding conditions. However, they wear quicker than sintered pads and are not as sharp as organic.

Bike disc brake pad compatibility

Disc brake pads come in many shapes and sizes to fit a particular brake.

The replacement pads need to be compatible but they don’t have to be the same brand as the brake on your bike. 

Some disc brake pads come with fins. These are ridged pieces of metal that protrude from the top of the pad. The stainless steel and aluminium structure maximises heat dissipation from the pad.

However, they do not offer any advantage for everyday riding and cost quite a bit more than their unfinned counterparts.

The pads have the ability to retract when the brake is released.

This is possible either thanks to magnetic pistons

or an external spring fitted between the pads.

While removing your old pads check if there is a spring and refit if required.

If you want to ensure good braking performance then when replacing the pads it’s good practice to also replace the rotor.

Tools required for bike disc brake pad replacement

Long nose pliers. These are used for straightening and bending the retaining clip and removing the pads.

Set of Allen keys/Torque wrenches. Many parts on the caliper require these tools.

Flat head screwdriver. Required for some retaining bolts and also for pushing hydraulic pistons back into place.

Isopropyl alcohol and cloth.  Required for cleaning the caliper before fitting the pads and cleaning the rotor.

Bike disc brake pad removal

• If you have a bike stand, put the bike on it and if you don’t turn the bike upside down. 

• Remove the wheel.

• If you have hydraulic disc brakes, position the screwdriver between one of the pads and the piston and gently push the pad against the other pad and this will force the piston back into the caliper.

• Now do the same on the other side.

• If you have a mechanical disc brake, use a 5mm allen key to release the cable on the caliper.

• Now reset the barrel adjusters on the brake and on the lever.  To do this turn them both clockwise as far as they will go.

• If there is a snap retainer on the retaining bolt, take it off. 7

• Now undo and remove the bolt.

• If you have a split pin retainer then use the long nosed pliers to straighten the end. Now slide the pin out.

• Slide the pads and spring out of the caliper. Note which side they fit as some retaining systems aren’t central. 

• If there is a retaining device for the pads, to remove them you will have to unscrew the piston on the non-drive side. Some pistons are held in place with a small grub screw.  If there is one, loosen it and then unscrew the piston.

• Unscrew the piston on the non-drive side.

• If there is a spring clip then remove this.

• First remove the drive side pad, if you’re struggling to grip it use your long nosed pliers to grasp the tab at the bottom and pull it.

• Now remove the non-drive side pad.

Fitting bike disc brake pad

• When fitting new pads it is important not to touch the braking surface. This is because our sebaceous glands produce an oily or waxy substance that can transfer and contaminate the pads.

• Clean the caliper using isopropyl alcohol and a clean dry cloth.

• If you have a caliper with a retaining mechanism, set the spring in between the pads and hold them together.

• Most finned brake pads need to be fitted the correct way round to better disperse the heat. The pads will be marked “left” and “right”. Fit accordingly.

• Now slide the pads into the caliper.

• Replace the retaining bolt and the snap retainer

or the split pin and bend back the long end using your long-nosed pliers

• For callipers without a retaining pin, first slide the non-drive side pad into place.

If the pad is sticking out beyond the side of the caliper, then loosen the non-drive side piston until the pad is level with that side of the caliper.

• Slide in the drive side pad.

• If there is a spring then slide it in between the pads.

• Now either replace or clean the disc rotor.

• Refit the wheel.

• Now you have completed bike disc brake pad replacement, it’s time to adjust the brakes. If you’re not sure how to do this our article here will guide you through this task.