How to Install Disc Brakes on a Mountain Bike: A Step-By-Step Guide

Are you looking for a guide on installing disc brakes on a mountain bike since you want to shift from V-brakes to disc ones?

The answer’s simple, “If the fork of your MTB is compatible with the installation of disc brakes, you can install them at home with the help of tools like Allen driver set and screwdrivers, etc.”

And below, we cover a step-by-step guide so that you can install disc brakes on your MTB bike conveniently. But before that, here are a few things you need to know about disc brakes and other parts of your Mtb.

Can You Install Disc Brakes On Any Bike?

Compatibility here is of prime importance! Some bikes are compatible with the installation of disc brakes, but unfortunately, you will find many bikes that do not offer disc brake installation.

Is Your MTB Frame Compatible with Disc Brakes?

Any frame compatible with disc brakes must have attachment points installed to ensure the discs’ mounting and other essential components.

Just opposite the drive system of the frame, you will find two holes used for installing the disc brakes. These holes are usually known as IS mounts.

Is the Fork Compatible with Disc Brakes

When it comes to the fork, it should also have the post mounts present to ensure the installation of the brakes. You can change your bike’s fork if it does not possess the post mounts if you want to shift to hydraulic brakes.

Are the Wheels Compatible With the Disc Brakes

We all know that the brakes get directly installed on the wheels, so they must be compatible with the disc brakes. There are two types of systems installed in wheels to accommodate disc brakes. You need to pick between Centerlock and 6 Bolt disc brakes. Here’s a little more about them.

Shimano Center Lock: Consisting of a unique spline on the wheel hub, the Shimano Center Lock accepts the disc (rotor) and locks it into the lockring. You can use different tools to tighten the disc, though.

6-Bolt Hubs: Wheels with 6-bolt hubs or threaded holes attaching the disc brake rotor could also work for installation.

Different Types of Bicycle Disc Brakes and Which One to Select?

Based on the size, the different types of disc brakes available in the market include:

  • 140mm 
  • 160mm 
  • 180mm and
  • 203mm 

We recommend the 160mm for your first experience with disc brakes. However, you can opt for bigger sizes (they offer a larger surface) if you want more power and control in your brakes.

Thing You’ll Need To Install Disc Brakes

Pre-assembled disc brake set from the brand you like

Screwdrivers: For attaching levers to the handlebars.

Set of Allen Keys: We’ll use them to attach the disc rotor to the wheel, usually consisting of 5mm bolts.

Torx Driver Set: For attaching the rotor disc bolts. We’d suggest getting a Torx T25 set as it’s available almost everywhere.

Torque Wrench: To adjust the torque of disc bolts and brake calipers.

Side Cutters: For cutting and trimming the zip-ties.

Rope Locker: Used for locking rotor bolts.

Bike Repair Stand: Installing the brakes becomes easy when adjusting the bike on a repair stand. You can get any bike stand you want, depending on your budget.

How to Attach Disc Brakes to Front Wheel?

Step 1: Remove V Brakes

First, adjust the bike on the stand and remove the traditional rim or V brakes installed on the bike using Allen keys and screwdriver. Similarly, you have to remove the handlebar levers.

Step 2: Remove Front Wheel

We’ll get started with removing the front wheel, as installing disc brakes is a little bit tricky on the front wheel. After installing the front discs, we’ll get back to the rear wheel later and install the brakes accordingly.

Step 3: Handle Disc with Care

While moving the disc and installing it on the front wheel, make sure that it does not get brake dust. A better practice would be to handle it while wearing gloves. You can use a clean rug with alcohol to clean the disc rotor properly.

Step 4: Adjusting Rotor on the Front Wheel

The first thing you are going to do is find a small arrow on the rotor. This arrow suggests the direction in which it should rotate. Double-check it before installing the rotor on the wheel hub.

As we are using a wheel with a 6-bolt system, start snugging the six bolts into the holes of the wheel hub. After that, loosen them up to ¼ as we’ll have to adjust the rotor later.

While you loosen the bolts a bit, move the rotor into the clockwise direction as long as the bolt holes allow. Please do not turn it forcefully as it won’t move much.

After moving the rotor in a clockwise direction, start tightening the bolts manually but in a star-shaped pattern to avoid bending problems.

Last but not least, align the rotor to the wheel hub and attach it using the 6-bolts or center-lock system.

For the 6-bolts system, you’ll need a thread locker. However, you will need a center lock BB tool to tighten the ring for the center lock ring.

Step 5: Clean the Disc Again

After aligning and adjusting the rotor on the wheel hub, take a clean rug with isopropyl alcohol or any other brake cleaner and wipe it off to remove any debris off it. Make sure that the disc is clean before starting with the following process.

Step 6: Re-attaching the Front Wheel

Re-attach the front wheel back to the fork the way you removed it in the first place. Similarly, select the front calipers and remove caliper spacers (red plastic piece) from them accordingly.

It’s always deemed good practice to install the spacers after removing the rotor from the calipers. Extending the calipers thus becomes easy and convenient for bikers.

Step 7: Align Calipers and Brake Lines

Next, slide the calipers over the disc and align the attachment points simultaneously. While you do that, keep the two bolts loosely attached and not too tightened. That is to make sure that you can still move them with your hands while adjusting the brakes.

As we already know, the front brakes always attach to the left side of the handlebar, direct the hydraulic brake lines to the left side. Attach the brake lever to the handlebars while loosely aligning the brake lines.

Start with a light squeezing the brake lever and spin the wheel up to 4 times to ensure that the calipers align appropriately to the disc brake.

Step 8: Adjusting the Torque

The installation does not end here. Now you’ll need to adjust the torque of the brakes so that they can work properly. Take out your torque wrench and set the torque range to either 75-80 in lbf or 8.5-9.5Nm.

After adjusting the torque range, tighten the caliper bolts until the torque is adjusted correctly. Give your wheel a spin again to make sure that it spins freely. We’ll adjust it again after taking a test ride on the bike if it rubs.

Step 9: Take a Test Ride

Ride your bike for half a mile and squeeze the brake levers on your way to check whether the brakes work fine or not.

If the wheel keeps on spinning, you can readjust the torque and lower it down a bit following Step 8 that we mentioned above.

Step 10: Zip-tie the Brake Lines

Zip-tie the brake lines with the fork and frame as per your requirements. Use a cutter to trim off extra stuff. 

Last but not least, adjust the position of the brake lever according to your hands and tighten them using screwdrivers accordingly. That’s all about installing the disc brakes on the front wheel.

Side Notes:

Before taking the bike for a test ride, do the bike bouncing test to check for any rattles. You have to lift your bike for like 4 to 6 inches and drop it back on the ground.

Do the tweaks if anything makes noise, and then take your bike for a ride to check whether the brakes are working correctly or not.

How to Attach Disc Brakes on the Rear Wheel?

Step 1: Remove Rear Wheel

Remove the rear wheel of your mountain bike and attach the rear brake to it using the same steps that we followed for the front wheel above.

Just make sure that you align and torque down the bolts in a star pattern to keep the disc away from bending.

Step 2: Routing the Brake Line

Routing the brake line could be tricky for the rear wheel.

Firstly, attach the calipers and then start routing the brake lines from the chainstay, followed by the seat tube and under the top tube to reach the handlebars.

Step 3: Attach Brake Lever

Loosely attach the brake lever on the right side of the handlebar and tighten the caliper bolts with the same procedure that we followed during installation on the front wheel.

Step 4: Tighten Brake Lever

Tighten the brake lever while adjusting the torque of the disc brake. You can either keep the same torque as the front wheel or modify it according to your requirements.

Step 5: Zip-Tie Brake Lines

Lastly, zip-tie the brake lines while ensuring that the handlebar can move freely. Trim the extra stuff using cutters.

Take your bike out for a test ride and check the efficiency of the disc brakes accordingly.

How to Adjust Mountain Bike Disc Brakes?

The need to adjust mountain bike brakes only arises when disc brake pads rub with the wheel. When that’s the case, remove the wheel and re-install it carefully to remove the rubbing problem.

If the rotor disc rub is slight, use a light behind the brake pads and move the wheel. It will show you whether the caliper adjusts in the center or not.

If you see that the calipers aren’t centrally adjusted, loosen the caliper bolts and re-torque the caliper bolts while holding the brake lever.

If the problem persists, loosen the single caliper bolt while the wheel moves freely and adjust it until the rub disappears. You can then re-torque it according to your requirements.

Benefits of Disc Brakes You Should Know

There are many benefits of hydraulic brakes over the common rim brakes, so we will discuss some of the most important ones as follows:

  1. Rim brakes can lose their stopping power after getting splashed into muddy water during wet conditions. Thus, you will not be able to stop your bike, especially if you are heading downhill. On the other hand, disc brakes are safe from splashes and maintain good stopping power.
  2. Even if the rotor does get wet, the force of calipers can wipe off water and extra debris from the disc.
  3. Disc brakes also offer better brake modulation with less lever force, thus ensuring more control over your mountain bike.
  4. Even if the rim bents during a ride, it will impact the disc brakes.
  5. Not only that, but the self-adjusting property of the disc brakes allows them to readjust without any maintenance. That’s certainly not the case when we talk about rim brakes.
  6. Even if a disc is bent or damaged, installing it is relatively straightforward and takes less time than installing rim brakes.

Recommended Disc Brake Brands

Shimano: Shimano disc brakes are currently the most popular items on the market. The best thing about this brand is that it sells complete brake sets rather than separate components.

This will not only cut down your costs, but you’ll also be able to install the brakes on your own. Shimano is, therefore, the #1 choice when it comes to disc brakes.

TEKTRO: The brand is relatively new compared to Shimano, but it offers disc brakes at an affordable price tag, and that’s what we recommend to mountain bikers who are low on budget.

SRAM: Another brand that you could try. But bleeding issues are common with SRAM disc brakes even though they are available at a cheaper price tag compared to Shimano disc brakes.

Related: Can Disc Brakes Overheat?

How much do Disc Brakes Cost?

A rough budget of the total disc brakes cost is no more than $100. However, that’s when you have all the tools available at your disposal. With the addition of the tools, the cost could rise to about $150 depending upon what type of keys and Allen head wrenches you buy.

That does not mean that affordable options aren’t available. Such brake sets will usually cost around $50. However, if you intend to go with a Shimano brake set, the cost will undoubtedly be higher than $100. With that being said, let us now move to the essential tools and things that you’ll need for the whole process:

Are Disc Brakes Better than V Brakes?

Compared to traditional V-brakes on mountain bikes, disc brakes offer an instant solution to stopping the bike.

Meanwhile, the expense of maintaining disc brakes on a mountain bike is zero once you get ahead with the installation. All in all, disc brakes are a better option than V-brakes when we talk about mountain bikes.

People Also Ask:

Can I put disc brakes on my mountain bike?

Hydraulic disc brakes can be installed when the bike’s frame, fork, and wheel are compatible. The frame and fork will usually have the IS mount holes available to integrate the brakes, whereas the wheel must have a 6-bolt or Shimano center-lock system to adjust the rotor disc accordingly. If your mountain bike has all these characteristics, you can easily install disc brakes on it.

Can I change my bike from rim brakes to disc brakes?

After ensuring that the fork and frame of your bike have the IS mount holes, you can remove the rim brakes using screwdrivers and Allen keys and get them replaced with the disc brakes easily.=

Final Takeaways:

That was all about installing disc brakes on a mountain bike with simple and easy steps. If you have all the tools available, it will take you no more than a hundred bucks to upgrade to hydraulic disc brakes.

With these brakes, you can experience improved bike control and stopping power, especially when you have to ride on rough downhill terrain.

Follow all the steps one by one to install disc brakes and take out your bike for a test ride to make sure that they are working correctly.

Photo of author
Written By Robert Gibbons
From riding to school since the age of 13, attending BMX races and events with his dad to himself conquering 50+ trails across the globe. For Rob, his Giant Stance 29 2 2020 is the friend that makes everything better. He is also a proud member of the International Mountain Bicycling Association (IMBA).

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