Getting frustrated by that annoying noise of your disc brakes rubbing against the rotor while you’re cycling?
Disc brake rub can not only be a nuisance but also impact your bike’s performance, leaving you feeling like you’re pedaling through treacle.
In this article, we’ll guide you through a quick and easy five-step process to eliminate disc brake rub and ensure a smooth, noise-free ride.
Whether you’re an experienced cyclist or a newbie, our step-by-step instructions will help you diagnose and fix the issue without the need for expensive tools or professional assistance.
We’ll be covering:
- What Is Disc Brake Rub?
- Why Are Your Disc Brakes Rubbing? 7 Common Causes
- How To Fix Disc Brake Rub in 5 Steps
- Robbie’s Video Maintenance Guide: How To Fix Disc Brake Rub
Let’s dive in!
What Is Disc Brake Rub?
Bike brake rubbing is the noise of the disc brake pads contacting the disc. This is a normal noise when the brakes are applied, but when they are not, it’s an issue that needs to be addressed sooner rather than later.
Sometimes, disc brake rubbing is a constant noise, and other times it can be a light brushing or “tinging” noise with every wheel rotation. It’s a very similar noise to having dirt on your disc brake. It’s unlikely to go away by itself, unfortunately.
If you have a bike with disc brakes, it’s a great idea to learn how to fix disc brake rub as it’s a repair you might need to do often.
It only takes a few minutes to solve when you know how!
Why Are Your Disc Brakes Rubbing? 7 Common Causes
#1. Warped Or Bent Rotor
A warped or bent disc brake rotor is one of the most common issues you will encounter.
This means the disc isn’t straight and connects with the pads inside the caliper on rotation. This typically happens when the disc either overheats or gets knocked in storage or while riding.
#2. Poorly Adjusted Caliper
A poorly adjusted caliper is another very common cause of bike disc brake rubbing.
#3. Worn Out Brake Pads
It’s not often that you will check your brake pads – perhaps only when your brakes get sloppy or during servicing.
If you find you’re getting a lot of disc brake rub, this often is because your brake pads have completely worn out and are down to metal.
#4. Dirt Stuck In Pads Or Rotor
This is definitely an issue for mountain bikers more than any other cyclists.
Having a dirty rotor means the dirt scrapes the pads, making the disc brakes rub. Normally, this clears itself, but sometimes you must take it apart and remove the dirt manually.
#5. Stuck Piston
If you are using hydraulic brakes, then you have pistons. When the lever is pulled, it drives fluid into the pistons, and they push the pads outward.
If these pistons get stuck out, they can cause brake rub and the brakes not to release. Using top brands such as Shimano and SRAM can help reduce the chances of faulty components.
#6. Inconsistent Pad Wear
Inconsistent pad wear can also be a big factor when it comes to brake rub.
It’s rare, but if the pads wear down incorrectly, it can eventually cause the pads to adjust inward and cause the bike brakes to rub on just one side.
#7. The Wheel Isn’t Seated Correctly
Another very common cause of brake rub is when the wheel isn’t seated in the dropouts properly.
When the wheel isn’t straight, it causes the bike brakes to rub on one side. This is very common when using quick-release skewers compared to thru-axles.
How To Fix Disc Brake Rub in 5 Steps
Fixing brake rub can be easy. I take the same route each time when I need to approach this task.
The process differs slightly depending on whether you use hydraulic disc brakes or mechanical. In this guide, we will explain the process for both.
What Tools Do You Need to fix Brake Rub?
There’s not a lot you will need when it comes to adjusting brakes. Here’s what I recommend, although you might not need it all:
- Allen Keys
- Flathead Screwdriver
- Tire Lever
- Bike Stand (optional)
- Rotor Straightening Tool (if straightening disc brake rotors)
- Torx Keys or Lockring Tool (if removing disc brakes or pads)
Step #1. Inspection
With the bike in the stand, spin the wheel to see the disc brakes rubbing. Start by checking the following:
- Is the wheel seated properly in the dropouts?
- Is the brake rotor bent or warped?
- Are the disc brake pads worn down?
If the brake disc rotor is bent, you need either a straightening tool or a new rotor. If the pads are worn out, you’ll need to get some new ones. We recommend getting these replacement parts before the next step, but only if you need them.
Step #2. Replace Any Parts (If Required)
If any parts need replacing, then follow this step. If not, move on to the next step.
First, remove the wheel to gain access to the disc brake. If you are replacing the disc itself, use the Torx keys or lockring tool to remove the disc from the wheel and swap it over.
If you plan on straightening the disc, put the tool on the bent section and straighten it.
To replace disc brake pads, remove the safety clip and unscrew the safety pin with a screwdriver. Pull the pads out and throw them away.
- Check out our complete guide on How To Replace Disc Brake Pads here!
If you’re using hydraulic brakes, use the tire lever to gently push the pistons back in the caliper, then put the pads in with the pin and clip.
If you use mechanical brakes, you don’t need to push the pistons in. Use the small Allen key fitment on each side to adjust the pads out slightly so they don’t rub.
Step #3. Reset The Caliper
Hydraulic Disc Brakes
Now, we need to reset the caliper.
If you have hydraulic brakes, remove the pads by undoing the safety clip, removing the safety pin, and pulling the pads from the rear.
Take the tire lever and then use it to push the pistons back into the caliper. Try not to be too forceful, as the last thing you want to do is break the seal or the piston.
Once the pistons are pushed back as far as they go, insert the brake pads again.
Mechanical Disc Brakes
For mechanical disc brakes, you must first locate the pinch bolt, which holds the cable in place, and completely release it. Next, pull the cable finger tight, and then tighten the pinch bolt back up again.
Then go to each side of the caliper and undo the adjustment bolts fully. This is so we can adjust them easily later and get the pressure as balanced as possible to avoid uneven pad wear.
Step #4. Adjust The Disc Brake Calipers
Hydraulic Disc Brakes
Next, it’s time to adjust the calipers.
For hydraulic disc brakes, start by unscrewing the caliper bolts half a turn each so they are slightly loose.
Then, pull the brake lever twice and, on the second time, hold it nice and tight. While still holding the brake lever, tighten up the caliper bolts. It should now be perfectly adjusted.
If it isn’t quite right, you can undo either caliper bolt and make micro-adjustments.
Mechanical Disc Brakes
For mechanical disc brakes, undo the caliper bolts by about half a turn. Then, pull the brake lever, which will lightly grip the disc. When it is gripped, tighten the caliper bolts back up.
Now, go to the Allen key bolts on the side and tighten them up until each pad is about 1 mm from the disc, or until you feel you have good leverage on the lever. The brakes should now feel nice and tight.
Step #5. Test!
Now, it’s time to give the bike a test.
Drop the bike out of the stand, ensure everything is tight, and then go for a ride. You should, at this point, have eliminated the disc brake rub!
I recommend taking an Allen key with you just in case, and if you still get a bit of noise, make micro-adjustments as required.
Robbie’s Video Maintenance Guide: How To Fix Disc Brake Rubbing
Check out the BikeTips YouTube Channel here for walk-through bike maintenance guides and more!
