The main reason behind the brake pads rubbing the rotor is the misalignment of the caliper. It reduces the gap between both sides of the rotors and makes noise when the wheel is spinning. Besides, if your rotors are bent, you may face the same problem.
Why Are My Brake Pads Rubbing the Rotor?
The new brake pads rubbing on the rotor is a pretty common issue if you have not ridden your bike for about 300 kilometers. And sometimes, you may face the same problem with your well-ridden bikes too. Though it might not slow you down all the time, it may seem to be annoying to you anyway.
Because of the pads rubbing, sometimes you have to put some extra energy while riding and you may feel some significant change in the speed and on the braking experience as well. In this case, your wheels are not being able to run freely and that is the key reason behind all of these.
There are some common reasons behind this disruption. One of the main reasons can be the bad alignment of the calipers. If the calipers are not aligned perfectly or not centered properly, it will prevent your wheel from moving freely by causing your brake pads to rub against the rotor.
To check if your rotors and brake pads are rubbing or not, or how bad your case is, you have to do some simple inspection. First of all, spin the wheel after elevating the bike. Then look closely at the calipers, how much gap there is between the pads and the rotor. If there is too much rubbing, you may have to fix the alignment.
Another key reason behind this can be rotor bent. As the rotor spins, it is quite usual that it would have some lateral movements. But a bent rotor may cause misalignment in the settings which causes the rubbing between the brake pads and rotor. Apart from that, rotors need to be secured by using either lockring or mounting bolts.
There are some other minor issues, that may cause this pad rubbing like sticky pistons, bearing play, etc. Contamination can be a valid reason behind this as time goes by. Sometimes it’s just the dirt and dust on the piston that may cause it to stick. If so, then you can easily clean that with a normal cleaner.
Fixing the bearing play is just a piece of cake for anyone. First of all, check the play at the hub. To do so, all you have to do is to rock your wheel back and forth. If you see any play, fix it.
How to Fix the Alignment of the Caliper
As far as rotor rubbing on the caliper is concerned, there are some simple steps to fix the alignment, so that the caliper remains at the center. Though you might have to follow the procedure more than once to achieve better precision. The alignment process is just the same in both rear and front brakes.
Before starting the process, you have to be sure that the wheels are seated properly. To do so, you have to unfasten the quick-release lever and then apply pressure downward with the bike on the floor. While pressuring, be sure that the axle and the frame are connected. Finally, fasten the quick-release lever.
Now if you are sure that your wheels are seated properly, you can start the alignment process.
Step 1: Loosening the Mounting Bolts
First, unfasten the mounting bolts till your caliper can move side to side freely.
Step 2: Centering the Caliper
Afterward, compress the brake lever. And this will center the caliper on the rotor.
Step 3: Tightening the Mounting Bolts
Now tighten the mounting bolts while you are still squeezing the brake lever. And then release the brake lever.
Step 4: Testing
If you have followed the steps thoroughly, spin the wheel to check for pad rub.
If there is no rubbing between the brake pads and rotors, the caliper is aligned perfectly. Fully secure all your mounting bolts and you are good to go.
But if there is still any pad rub, you have to put some extra effort into some fine-tuning.
Step 1: Spin your wheel and loosen up only one bolt at a time while the wheel is spinning.
Step 2: Use a rigid thin tool to push the caliper in the direction of the rubbing to create a significant gap between both sides of the rotor.
Step 3: If you can not fix the alignment, tighten up the bolt mounting and loosen up another one and follow the same step. Once the pad rubbing stops, secure the bolt mounting to get the full torque.
This way you can fix new discs and pads rubbing. During the process, be extra careful when you are working with your fingers on the spinning wheels.
How to Fix the Bent Rotor
To check if your rotor is bent or not, you have to spin your wheels and look at the calipers. Now see if the disc moves side to side or not and if it does, see if the disc is touching the brake pad or not. If it does, surely you are having these new discs and pads rubbing due to rotor bent.
So, if rotor bent is the reason behind the disturbance of your wheels spinning freely, you certainly have some great options to straighten it up and fix it.
To straighten the disc up, you can either use some professional tool like an adjustable spanner or you can use your hand. Now as you start, the first thing you need to do is to observe how much bent your rotor is. If it is too bent, you might have to buy a new rotor.
But if it is not, then see the direction of the bent and use your tool precisely to straighten it up. While fixing, be sure that the rotor is straight as much as possible. Because if you bent it too much, it will ruin the alignment and the situation might get worse. Keep spinning the wheel after straightening up the rotor for better results.
Frequently Asked Questions
Q: Why is there noise in my new bike?
Ans: If your bike is not well-ridden, you might have such kind of problem. In this case, the noise will go by itself after a while due to friction.
Q: Why there is scrapping or grinding noise in my bike?
Ans: The key reason behind this might be the misalignment of the caliper. If the caliper is not aligned perfectly or not exactly centered, you might experience some grinding or scraping noise.
Q: Do I need to replace my pads due to rubbing against the rotors?
Ans: No, you don’t need to do so if you can fix the alignment of the caliper or your bent rotor. But if your brake pads have a wearing issue, then you must replace them.
It is not uncommon for new brake pads to rub on the rotor. In that case, it is better to be patient if you are okay with a little noisy ride. But if you are not, fix the alignment and have a smooth ride.