Understanding how to adjust bike disc brakes is a useful skill that will definitely come in useful if you are a frequent cyclist. It is one of those tricks that is simple to learn but requires patience to master. Don’t give up, it’s worth sticking with! After all, riding a bike is one thing, stopping is all together more important!
Before you try to adjust your disc brakes, you will need to check if you have any problems that be prevent you from making the required adjustments . If you have cable disc brakes, check to see if the cable moves the caliper arm and allows it to spring back to its normal position. If it doesn’t, then you might need to change the entire cable. We have a great blog post and video on bike brake cable replacement. Now check your static piston. If it doesn’t turn or the hole at the back of it is rounded, you may need to fit a new caliper.
if you have hydraulic disc brakes, and it feels soft, or you have to pull the lever all the way to the handlebar before it engages you may need to bleed the brakes first. You can find out how on the Cycle Maintenance Blog
If the brake is rubbing and slowing the wheel down, it might be that some of the seals in the caliper or lever have expanded or the pistons are too silted up to retract. If this is the case, you might need to consider having a service of your brake or replace it.
Check to see if your rotor is badly bent. If it is, straighten or replace. We have a great video here if you want to know more about rotors.
Check your pads if they are worn or contaminated then replace them. Watch the video here if you need help with this task.
How to adjust bike disc brakes that are hydraulic
Put the bike on a stand or turn it upside down. Loosen the caliper fixing screws just enough to allow the caliper to move from side to side in the slots. Press and hold the brake lever. Push the caliper left or right so that the pads sit centrally over the rotor and gently tighten the bolts sequentially. Release the lever and spin the wheel to check if the caliper is set to the correct position. There might be a tiny rubbing noise, and this is acceptable. If however the pads are still rubbing significantly and slowing the wheel then you might need to do further tuning.
Loosen the caliper fixing screws just enough to allow the caliper to move from side to side in the slots. Now, look at the gap in the caliper. By hand move, the caliper left and right finding the point where you can see daylight passing through between the pads and the rotor. The gap should be even on both sides. While holding the caliper in place use your other hand to gently tighten the bolts sequentially. If you do it too fast the caliper may move. Spin the wheel to check if it rubs. If required repeat the process until you’re happy.
