How to replace rim brake pads

It is important when assessing the condition of your brake pads to take the time to look at each pad individually. This can tell you a lot about your brakes and the performance they have been offering you.

Most brake pads will have a small wear line marked on the top of the pads. Once the pads have worn to this limit, it is time to replace them. If they don’t have a line, when there are just a few millimetres of pad available, it's time to replace them.

Looking at how even the pads have worn compared to each other, and seeing if they have worn evenly across the pad, will show you if you have any issues with the balance and setup of your brakes. If they are set up well, both pads should be worn equally across the whole pad material.

Once you have identified that it's time to replace your brake pads, it's time to get the bike ready for the task. Placing the bike in a work stand that's set at a comfortable height for working on the brake callipers will make the job a lot easier. So too will removing both wheels and cleaning the brakes with either a degreaser or a specific brake cleaner.

Almost all rim brake bikes use a system called cartridge brakes, this means that the pad material slides into the cartridge that is then fitted to the calliper. This allows the pads to be set to the correct position and then the pad material can be removed and refitted multiple times without the need to reset the pad position every time. In order to remove the pad material, firstly remove the 2mm grub screw that retains the pad.

Once the grub screws have been removed, set them to one side and inspect them for any damage. It can be useful to add a smear of grease on the threads before refitting them to prevent them from seizing, making your life easier next time.

Using your thumbs should be enough to extract the pads from the cartridge, although they can be a little bit tough and could take some working to get them to slide off. It is advised that you don't use anything else to try and ease the pads off as this could cause damage to the frame or fork if you slip.

Fitting the new brake pad is almost as simple as doing the reverse of what you did to remove the old ones, however, take note of any writing and arrows on the pads. Typically they will have an arrow labelled forward and a denotation marking to show which side they are for. These markings are to ensure that the cutout in the back of the pad will line up with the retaining grub screw and will hold the pad in place.

Now that the new pad is in place, it's time to fit the retaining grub screws. Make sure you are delicate with them – it's very easy to cross-thread them or damage the head of the screw. The grub screws do not need to be done up overly tight and a torque of around 2-3Nm should be enough.

With the wheels refitted, it is likely that the wheels are rubbing against the brakes, as all that fresh pad material is taking up a lot more space. In order to compensate for this the brake barrel adjuster needs to be wound out to a point that the pads are not touching the rims and you have the desired lever throw.

The final checks to make before heading out for a ride is that the pads come into contact with the correct section on the rim, and that the pad meets the rim at a nice square angle.