Bicycle Disc Brakes – How to Choose the Right Brakes

bicycle disc brakes featured image

The earliest inventors of two-wheeled cycles could not have imagined the sophisticated bikes we ride today or the myriad choices we are faced with when it comes to upgrading and outfitting them.

Much like car enthusiasts, who could spend hours discussing the merits of a manual transmission, those passionate about cycling are prone to unusual levels of excitement when speaking of cranksets and calipers. Perhaps they are ready to debate the best rotor or eager to ask other cyclists about favorite forks (and we do not mean forks in the road, for any newbies out there. We mean part of the bike’s frame.)

red road bike during sunset on green grass

Perhaps you do not yet speak “cycle” fluently: you enjoy cycling, you have invested in a good road bike or perhaps splurged on a gravel bike on a day you felt really gutsy, but you do not spend hours on end reading about bike parts or talking shop with others in cyber cycling chat rooms.

If you are not an expert on bicycle disc brakes, but you need to know how to choose the right ones, rest assured we have you covered here. You do not have to be a bicycle mechanic or a longtime cyclist to develop a good basic understanding of disc brakes and how to choose them.

A word of caution, however: you may want to have a bike mechanic install them for you (or at the very least inspect them before you set off on a long ride).

Many cyclists are quite handy when it comes to changing out parts and making minor repairs on their own bikes, and we are not here to crush your DIY dreams. But considering the importance of the brake’s functionality when it comes to keeping you alive, this is not something you want to do a mediocre job on or just assume you can “give it the old college try.”

Just because the pilot can fly the plane does not necessarily qualify her to repair its engine, and just because you know how to ride a bicycle, you are not necessarily equipped to install its brakes.

yellow bicycle tire and brake close up

If you have any doubt about your ability to install brakes correctly, please leave it to the experts! Nearby pedestrians, bus drivers, other cyclists, and anyone in your path will thank you for that.

Now that the “fine print” warning is out of the way, and we have made this commonsense suggestion to (hopefully) prolong your life (and your cycling days), we will dig into the ins and outs of bicycle disc brakes and how to go about choosing the right ones.

Bicycle Brakes: A Quick Overview

Back when people rode “penny-farthings” (can you imagine if this name had actually stuck?), an early spoon style brake is the mechanism that slowed the rider down. As the penny-farthing evolved into what became today’s bicycle, the mechanisms for stopping also evolved and changed and improved for riders.

When a tire filled with air (versus solid rubber) became commonplace in cycling, a stopping mechanism that did not touch that tire was necessary. Coaster brakes were conceived and are still used today in kid’s bikes (as well as some beach cruisers). This system is tucked away in the shell of the rear hub, where it is protected from the elements, and the stopping power is activated by a change in pedal direction.

Coaster brakes serve their purpose and, of course, make it easy to train children to ride their bikes when their coordination skills are not yet finely tuned to the point they can rely only on hand brakes.

However, as cycling evolved from a leisurely pastime into a full-fledged sport and a way for adrenaline junkies to seek out thrilling and speed-filled experiences, the need arose for a more sophisticated braking system. In other words, as we got faster, brakes had to keep up, too.

After coaster brakes, both drum and rim brakes made their way into the cycling pictures. Drum brakes were trickier to incorporate into the frame design, and rim brakes surfaced as the favorite of those two. As the name implies, a rim brake simply squeezes on the rim to slow the bike down. Over time many variations of rim brakes have developed, and they are still in widespread use today.

Disc brakes first came on to the cycling scene around 1950 but only really took off when mountain biking skyrocketed in popularity.

What Are Disc Brakes and How Do They Work?

The brake that first appeared mainly on mountain bikes is now seen on many racing bikes as well, and it is comprised of a rotor (which is a metal disc, hence the name disc brakes) and calipers attached to the frame or fork of the bike. The calipers work in conjunction with pads to squeeze the rotors, enabling the rider to slow the bike down and ultimately stop.

Thinking back to coaster brakes a rider can control with their feet, a cycling novice might ask here, “what makes the caliper and the pad squeeze the rotor?” There are actually two ways to answer this question.

A disc brake can be set into slowing and stopping motion in two different ways: by cable (mechanically) or hydraulically. The cable method is easy enough to conjure an image in your mind if you have even the most basic bicycle knowledge. However, imagining this process taking place hydraulically is perhaps a bit more of a stretch for your mind.

However, if you think about what it means for a hydraulic process – which is essentially liquid moving in a confined space – you can begin to imagine how a system of hoses and reservoirs could be built into a bike to manage the braking process.

In the case of a hydraulic brake, that hand lever, when squeezed, sets into motion a process where fluid is pushed through hoses that in turn reach the caliper and push the pads into the rotor.

close up of rival bike brake

Whether it is with the “old fashioned” cable or the hydraulic fluid, what remains the same in both cases is that a rotor must be stopped to stop the bike. And in both cases, you want a high-functioning brake on a steep descent (or in traffic in town…or anywhere really!)

focus of bike gear

One of the most significant parts of the disc brake’s functionality, and what sets it apart from rim brakes, is the brake pad. A rim brake pad is going to be softer and, therefore, more susceptible to the elements. In the world of mountain biking (or adventure/gravel biking), cyclists need something that can stand up to mud and debris and often more adverse weather conditions.

The disc brake pad will be metallic or ceramic-based, designed to better withstand these elements.

Mechanical Disc Brakes Versus Hydraulic Disc Brakes: Pros and Cons

Mechanical disc brakes are often favored because they are simple, lightweight, and cables are less expensive than hydraulic lines.

Unfortunately, these systems also come with what is known as “cable stretch.” Over time as the cable lines stretch, the braking power is diminished. Therefore, you will need frequent adjustments.

While hydraulic lines are more expensive, the fact that they are ensconced in a “closed” system means they are not susceptible to debris like cables are and this gives them more staying power.

One drawback with hydraulic brakes – especially for DIYers – is that they require absolute precision in setup and may not be something a cyclist should “tinker with” as much as cables. Even the tiniest leak in hydraulic discs could cause an absolute brake failure, which could be an absolute cycling disaster. It is always in your best interest to have your local bike shop inspect hydraulic brake systems.

How to Choose the Right Disc Brakes: Four Items for Your Checklist

Hydraulic Versus Cable

You now understand that there are some significant differences between hydraulic and cable disc brakes, and this will be one of the first decisions you will make as you narrow down the choices for your bike.

Pricing may be a big part of your decision, both with the initial investment as well as the consideration for future repairs, replacing brake pads, etc.

Budget is clearly something most of us have to keep in mind when it comes to spending on our hobbies (and cycling can certainly be an expensive one). However, if there is one area we would say you should NEVER skimp on, it would be brakes.

While it is true that brakes may not be as “sexy” as tires, for example, they are so important that it is not worth trying to find too many savings in this area. Get the best brakes you can within a reasonable budget, whether that means spending a little more on hydraulic or buying the best cable disc brakes that are a good fit for your bike.

Even if you are handy enough to install and/or upgrade your own brakes and plan to order them online, it is always worth a second opinion from the experts at your local bike shop before settling on the final choice. And post-installation, it would be a good idea to have them inspected by the bike shop, too.

black road bike

Pads

The pads associated with the braking system will be part of your decision-making process, too. As we already pointed out, one of the advantages of the disc brake system (versus traditional rim brakes) is that the pads are made of materials that can better withstand debris and the elements. Even though this is the big “pro” for disc brake pads, they also come with some cons.

If you choose a braking system with organic or resin pads, the trade-off is this: you will get a quieter brake, but the pad will not last as long. On the flip side, a metallic pad has greater staying power, but it creates more noise.

The noise could be a great nuisance to some cyclists or barely a bother to others. Before you decide, ride bikes with each kind of pad to see what the experience is like.

Oil Versus Fluid

The importance of “oil” is not just a topic for car buffs! To be fair, though, we are just talking mineral oil here.

The brake system you choose will either require mineral oil or fluid, and you need to pay attention to the manufacturer’s specific recommendations. The improper use of fluids can do great harm when it comes to disc brakes. In fact, it could eventually lead to brake failure.

The use of mineral oil or brake fluid comes into play with brake repairs, so this is yet another time we will point out that if you are unsure about what to use, contact your bike shop. Do not risk using the wrong fluid and ruining your seals or causing the brakes to fail altogether.

water bubbles

The Most for Your Mount

Now that disc brakes are crossing over into the world of road bikes, there have been some changes to how they are mounted. This is another area you will consider when choosing disc brakes: what is the specific type of bike you are using, and how does that dictate how the disc brakes will be mounted?

Disc brakes on mountain bikes are placed in a post-mount design, but a flat-mount works better on a road bike. Now that flat-mount is increasing in popularity, some adaptors will allow you to transition from post to flat (but flat to post adaptations are less common).

Disc Brakes for Every Budget

Shimano MT 200

Actuation: Hydraulic
Mount: Post

This is an affordable hydraulic brake set from a trusted name in the bike business. Shimano makes solid products, and their brakes are no exception. Resin pads are included, so buyers should note they will need to change them more frequently.

While the MT 200 brakes are geared toward mountain bikes, they can work on a wide variety of bikes. Mineral oil is used with these brakes, and buyers should note that rotors will need to be purchased separately.

All in all, this is a great brake set at a great value.

jgbike shimano mt200 hydraulic disc brake set

SRAM G2 Ultimate

Actuation: Hydraulic
Mount: Post

Made of titanium and carbon fiber, the Ultimate is SRAM’s newest (and lightest ever) hydraulic disc brake. It is the “ultimate” in a disc brake with an ultimate price tag to boot. Steel-backed organic pads are built to last in this system. If it’s the highest quality you are after, these brakes will not let you down.

SRAM claims the Ultimate boasts a seven percent power increase over its predecessor, the Guide.

The G2s require DOT 5.1 brake fluid, and cyclists appreciate that actuation is light and easy. The Power Organic Pad Compound also lends itself to the increased power in braking.

sram g2 ultimate

Paul Component Klamper

Actuation: Mechanical
Mount: Post
Weight: 211g

If you think brakes have to be “bland,” this one will prove you wrong. The Klamper is infused with personality, right down to its color choices. But this is not just about looking good and making your bike stand out from the crowd: the Klamper really performs.

Made of aluminum and steel and crafted in Chico, California, with sintered metal brake pads, the Klamper is a solid and durable choice that also happens to be a favorite for those who like things a little on the flashy side.

While this is an especially large brake, it is designed this way to make the calipers extremely rigid. This company’s knack for detail and near obsessiveness in perfecting brake design means the user ends up with an incredible product.

paul component klamper bicycle disc brake

Shimano Ultegra

Actuation: Hydraulic
Mount: Flat

Many cyclists swear by Shimano, and the ease and comfort in using these brakes are almost unbeatable. A minimal lever pull brings a big response out of the Ultegra, and this is a hydraulic brake that may convert longstanding mechanical disc brake riders. They come with Shimano’s IceTech finned brake pads.

Those with sticker shock need not apply, however. Shimano quality will cost you a pretty penny, and these are a significant investment for serious bikers.

shimano ultegra hydraulic disc brake rear caliper

SRAM Red AXS

Actuation: Hydraulic
Mount: Flat and Post

This brake stands out in the industry as it is available in both flat and post mount. The Red AXS is a high-performing brake system with an updated fluid circuit. For those who do not “speak hydraulic,” this means that the piston bores respond perfectly. If we lost you at piston bores: this is a smooth braking system. Period.

The SRAM Red AXS Groupset comes with a high price tag, and this is another line geared toward serious cyclists.

sram red axs bicycle break set

Brake Care and Maintenance

Once you have chosen and installed the perfect disc brakes for your bike, the work is not over. Sure, a good set of high-quality disc brakes should perform well for a decent period of time, but brakes, just like other parts of your bike, will need maintenance to extend their life.

Just as it is unwise to ignore the “check engine” light illuminated on the dashboard of your car, it is unwise to ignore the various ways our bikes “talk” to us to tell us the brakes need a little attention and some TLC.

At a minimum, and even without signs of a problem, you should have your brakes inspected at your local bike shop once a year. If you ride frequently and on rough terrain, you should do it more often.

Disc brake pads will wear down, and you should be able to spot this by removing the wheel to take a closer look at them. If they have worn down to a thickness under three millimeters, you will need to replace them.

If the brake pads are squealing, that could be due to contamination of some sort. Oil, even from your own skin, can affect your brake pads. Whenever you are working on your bike, take care to wipe the pads down with rubbing alcohol if you have touched them.

Occasionally the bike pads simply need to be repositioned and not replaced. Again, if you do this, take care to wipe them down with alcohol after touching them.

Rotors can also be cleaned off with alcohol if they have collected too much debris and then rubbed down lightly with a bit of sandpaper.

With hydraulic disc brakes, “bleeding” may be needed from time to time as well. This refers to a process where you purge small air bubbles out of the hydraulic hoses. It is advised to seek assistance from your bike shop with this repair.

Whether your bike’s disc brake system is hydraulic or mechanic, the various components all need to be looked after and cared for to function properly.

Last Updated on March 8, 2021 by Matthew Carpenter

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