Last week we took you through how to replace your brake cables for greater stopping power. However, you also need to make sure that your brake pads are in good shape too. Brake pads frequently wear out so this week we show you how to replace the brake pads on most styles of rim brakes.
To see if new pads are needed simply check to see if the grooves have disappeared (see image below). If you haven’t replaced your pads in a couple of years then it is a good idea to get some new ones. If you are pulling an old bike out of the shed, it is also worth replacing the pads as they can dry out. Changing the pad cartridges is the easy part, getting them in position is where you need to spend some time tinkering.
It is best to approach this one brake pad at a time. Use your Allen key to hold the eyebolt still. Then using a wrench, loosen the nut at the back. Don’t take it all the way off just enough to allow for movement.
Thread the brake pad that needs replacing out and thread the new one in. Position the new brake pad facing the rim and tighten the nut to loosely hold it in place. Don’t worry too much about delicate adjustment that comes later. Repeat this process with the brake pad on the other side.
Now to adjust the cantilever brakes. If you have the link wire type of brakes then undo the bolt holding it in place. Pull more wire out or let more in until you have adjusted it to a 90-degree angle. The other type is straddle wire and this can be adjusted from the height of the straddle hanger and the length of the straddle wire. Again, aim for 90 degrees alignment of the two hanging wires.
Push each unit together so it is touching the rim. It should not touch the tyre at all (like it is in the picture above) and should sit in the middle of the rim. If it needs adjustment just loosen the nut on the back of the brake unit and slide it up or down.
Once everything is re-tightened try to move the brake pad with your hand and check it doesn’t move. Give the brakes a squeeze to test they are working. Also, spin the wheel to check there is enough clearance between the pad and the rim, so that they are not touching.
V brakes, and mini-V brakes, are common on many mountain and hybrid bikes. Whilst the replacement is fairly simple it is tough to get the alignment just right and it can take time to tinker with it. You’ll need a new pair of brake pads that are similar to your current ones and an Allen key.
Loosen the bolt holding the brake pads in place. Then remove it and the washers. You should check the new brake pads to see if they come with any specific installation instructions. This is important as installation can vary slightly. You can also use existing brake pads as guidance to how the new pads should be installed. Fit the brake pad into position.
Add the remaining washers to the other side of the brake pad in the correct order. Then loosely fit the nut using your Allen key. This will allow you to manoeuvre it into the correct position.
Set the position of the brake pad so that it does not touch the tyre and it does not hang-off the side of the rim when the brakes are applied. Also, the pad should meet the rim at 90 degrees.
You may need to do something called “Toeing-in”. This is where the front of the block, which faces in the direction the bike travels, should be slightly closer to the rim than the back. This helps prevent the brakes from squealing. Not all v-brakes require toeing in. To determine if yours do simply ride with them for a while and if they squeal then toeing in can help. You can achieve this slightly forward leaning alignment by pushing the pad into the position you want and re-tightening the bolts.
Finally, tighten the nut firmly. Tightening the nut can be tricky, as when you are tightening it the pad will attempt to move. Try holding it in place with your other hand. Test it is tight enough by trying to twist the pads by hand. If you can twist them then you need to tighten it further.
When installing new brake pads it is likely you will need to adjust the brake cable tension so that the wheel can spin round freely without touching the brake pads. Usually the rim should sit 2-3mm away from the pad. If only a small adjustment is needed then twisting the barrel adjuster can do this. Bigger adjustments may need loosening of the cable clamp bolt. You should adjust it so that when the brakes levers are applied half way the brakes should be fully engaged.
If further adjustment is needed unscrew the cable clamp bolt and then either release more slack in the cable or pull it more tightly. Then retighten the bolt and ensure the wheels move round without touching the pad. Also check to see that when the brake levers are pulled half way the brakes are fully engaged.
It may take a while before the brake pads reach their full braking potential. Cycle slowly to work them in at first. You should also test the brakes a few times after replacement to be sure they are tightly fastened and working correctly. It is also worth wiping down the rim surface to be sure they have a good braking surface. You should aim to always have a pretty clean brake pad and rim surface as otherwise both will wear prematurely.
Do you have any tips for changing brake pads easily and efficiently? Let us know!