Speeding along on roads and trails might be the most fun part of cycling, but even more important is the opposite: braking safely and effectively. This article will cover two particular kinds of brakes most commonly seen on modern bikes, mechanical and hydraulic disc brakes.
Before we get into that, it should be mentioned that disc brakes are only one kind of bicycle brake. The other kind typically seen nowadays is rim brakes, which stop the bike by squeezing two opposing brake pads against the rim of the bike wheel. These mechanisms are typically mounted on the frame near the upper part of the wheels.
While rim brakes used to be the most prevalent kind of braking system, they’ve largely been replaced by disc brakes, which have superior stopping power (i.e., the ability to come to a complete stop quickly), especially in inclement conditions.
So, what’s the difference between mechanical and hydraulic disc brakes? That’s what we’ll cover below. Understanding the differences will help you identify which features are most important for your riding style/preference. Key factors in choosing which kind of disc brake you need include the following:
- Style of riding (road, mountain bike, hybrid, commuter, etc.)
- Typical riding conditions (hot or cold, rain, snow, mud/dirt/gravel, etc.)
- Cost
- Performance needs (smooth braking, sudden stopping power, etc.)
- Maintenance considerations
What Is a Disc Brake?
Bicycle disc brakes are different from rim brakes in that they use a brake pad to squeeze against a rotor mounted around the hub of each wheel to stop the bike. Many disc brakes (especially on road bikes) feature a one- or two-piston design in which the piston(s) on each side of the caliper (which is a clamp that slows down a bike’s wheels by creating friction) are pushed inwards to squeeze a brake pad against the rotor. (Mountain bikes may feature a higher number of pistons for increased stopping power.)
Disc brakes have several advantages over rim brakes, including the following:
- More stopping power: Especially in wet or sloppy conditions, disc brakes have greater stopping power, even at high speeds (making them particularly effective for steep descents and rapid deceleration). This increased braking power means your forearms won’t be screaming at you for squeezing the life out of your brake levers all the time.
- Braking control: Disc brakes aren’t only more powerful, they’re also more precise, allowing you to stop more quickly and accurately, and at the preferred speed. This ability to provide degrees of braking intensity is known as modulation and helps avoid skidding. Disc brakes can be even further modulated by changing the size of the rotors.
- Weather compatibility: Disc brakes are more resilient in inclement weather, so they won’t lose power in mud or precipitation.
- Cleanliness: Related to their durability in inclement conditions is the fact that disc brakes stay cleaner for longer amounts of time, since they’re positioned further away from the dirt and moisture that can be kicked up by bike tires than rim brakes.
- Longevity: Unlike rim brakes, which cause both the brake pads and the rims to be worn down over time, disc brakes only apply friction to the rotors on the brakes, helping them last longer in most cases.
- Flexibility: By removing the platform needed for rim brake calipers, disc brakes have enabled bike designers to be more creative and innovative with aerodynamic shapes, carbon construction, wider tire clearance, and streamlined engineering, with cables and/or hydraulic hoses being integrated inside the frame.
Now that we have a decent understanding of disc brakes, it’s time to go into the differences between mechanical and hydraulic disc brakes.
Mechanical Disc Brakes
As mentioned above, disc brakes use a brake pad to apply pressure against a rotor mounted around the hub of each wheel. With mechanical disc brakes, that pressure travels from the brake levers to the calipers through a cable, typically made of steel.
When the brake lever is pulled, the cable pulls an actuator arm in the brake caliper. This pushes either one or both brake pads together until they clamp down on the disc rotor, slowing the bike down.
Mechanical disc brakes are known for their reliability and simplicity, falling between rim brakes and hydraulic disc brakes in terms of their stopping power and braking performance. More info on mechanical disc brake pros and cons can be found below.
While mechanical disc brakes can be found on nearly any type of bike, they’re especially common on entry-level road, commuter, and gravel bikes, as well as touring bikes. Lower-end mountain bikes may also feature mechanical disc brakes, although this is becoming a rare sight.
Hydraulic Disc Brakes
Although mechanical disc brakes provide solid stopping power, safety, and reliability, hydraulic disc brakes are seen as the superior option. Instead of a cable to connect the brake levers and calipers, hydraulic disc brakes utilize a closed system of hoses, reservoirs, and a cylinder to move hydraulic fluid through the bike, ultimately applying pressure to the brake pads.
In this system, when the brake lever is squeezed, a plunger pushes brake fluid through the hoses and into the brake caliper. Once enough pressure is built up, the fluid pushes against the pistons inside the caliper, moving them toward the rotor and slowing the bike.
Hydraulic disc brakes have numerous advantages over mechanical disc brakes (not to mention rim brakes) and are seen as the premier option for bicycle braking, with unmatched stopping power and modulation for the ideal blend of performance and a smooth, natural feeling. More info on hydraulic disc brake pros and cons can be found below.
Because hydraulic disc brakes are costlier and require specialized tools to repair, they’re typically featured on high-performance bicycles, electric bikes, and the vast majority of mountain bikes, which require optimal stopping power for off-road riding.
Comparing Mechanical and Hydraulic Disc Brakes
For a handy, at-a-glance comparison of mechanical vs. hydraulic disc brakes, take a look at our infographic (and for more detailed information, keep reading!):
| Mechanical Disc Brakes | Hydraulic Disc Brakes | |
|---|---|---|
| Stopping power | Reliable stopping power, though less powerful than hydraulic disc brakes | Optimal stopping power |
| Engineering | Cable(s) from brake levers to calipers | Operates through a closed system, using hydraulic fluid to transfer force from levers to calipers for efficient braking |
| Modulation | Offers better control than rim brakes, but less precision compared to hydraulic disc brakes | Fine-tuned, with a smooth, natural feeling |
| Cost | Moderate but affordable | Premium option |
| Maintenance | Simple and reliable, needing few repairs | Closed system needing occasional specialized repairs (e.g., brake bleeding) |
| Longevity | More durable than rim brakes, but less durable than hydraulic disc brakes, with erosion of brake pads over time | Most durable and long-lasting, with excellent heat dissipation |
| Self-Centering | No; may need occasional realignment | Yes; don’t need to be readjusted for position |
| Weight | Heavier than rim brakes and hydraulic disc brakes | Heavier than rim brakes, lighter than mechanical disc brakes |
In short, if you’re looking for an entry-level or more affordable bike with decent, reliable braking power, mechanical disc brakes should be sufficient. But if you’re an avid mountain biker, you’re investing in an electric bicycle, or you want a top-of-the-line vehicle, hydraulic disc brakes are the way to go—and you’ll quickly realize how much less tired your hands and forearms are with hydraulic disc brakes after a full day of riding.
Performance
Mechanical Disc Brakes
In terms of performance, mechanical disc brakes fall in between rim brakes and hydraulic disc brakes: they have decent and reliable (not top-of-the-line) stopping power, even in poor weather conditions.
However, they require greater hand and arm strength to apply pressure to the brake pads than a hydraulic system, so mechanical brakes can lead to a sense of body fatigue.
But if you typically do more casual (or even semi-rigorous but relatively flat) riding, mechanical disc brakes are acceptable for many cyclists.
Hydraulic Disc Brakes
If stopping power and performance are your top priorities, you’ll want to go with hydraulic disc brakes—there’s nothing better as far as bike brakes go. Mechanical brakes simply can’t match the power, consistency, and lever-feel of hydraulic braking systems.
That’s why practically all mountain bikes (certainly medium- to high-end ones) come equipped with hydraulic disc brakes these days. For challenging downhill rides and technically advanced trails, you basically need hydraulic disc brakes.
They’re easier to apply force from the brake levers than mechanical systems, so you won’t get tired as easily, and they offer improved adjustability so cyclists can fine-tune their brake lever position and pad-to-rotor contact point.
Price
Mechanical Disc Brakes
This is one category in which mechanical disc brakes have the clear advantage. As the middle-of-the-road option between rim brakes and hydraulic disc brakes, mechanical options are both reliable and affordable, making them ideal for budget-conscious riders. That’s why mechanical disc brakes are typically seen on entry-level or commuter bikes that don’t require maximum performance and versatility.
Hydraulic Disc Brakes
Is the increased price point of hydraulic disc brakes worth it? That’s up to each rider to decide. The advanced technology and performance benefits of hydraulic systems may be a must-have for some cyclists, especially if they’re more experienced or often navigate challenging MTB trails. If it’s important to you to outfit your ride with the best-possible gear and accessories, hydraulic disc brakes are the way to go.
Maintenance
Mechanical Disc Brakes
This is another category in which mechanical disc brakes have the slight edge. If you’re a set-it-and-forget-it type of rider who wants to deal with maintenance issues and repairs as little as possible, then mechanical disc brakes will offer both reliability and simplicity. There’s just not much that can go wrong with mechanical disc brakes (though, of course, you should always expect the unexpected in the world of cycling).
While mechanical disc brakes do require occasional fixes, like cable adjustments and pad replacements or realignments, these are usually simple enough to be done at home by DIY bike mechanics. It’s easy to find replacement parts, and the tools needed for these repairs can be found in most bike shops or toolboxes.
Hydraulic Disc Brakes
The most challenging maintenance that needs to be done on hydraulic disc brakes requires “bleeding” the brake lines—i.e., changing the hydraulic fluid to remove gas as well as metal and rubber particles. Bleeding the hydraulic brake system is a specialized repair that usually requires the assistance of an expert mechanic. That said, you should only have to do this about once a year, so even then it’s not prohibitive.
There’s also the simple fact that hydraulic brakes are a sealed system fully integrated into the frame of the bicycle, so it’s more difficult to access in case anything does go wrong.
While maintenance on hydraulic disc brakes might be more involved, the performance benefits justify the efforts and expenditures for most riders.
Modulation
Mechanical Disc Brakes
As mentioned above, “modulation” is the ability to provide degrees of braking intensity, leading to a smoother, more natural feel and avoiding skidding abruptly.
Unfortunately, mechanical disc brakes offer less modulation than the hydraulic kind, leading to an “on or off” feeling with little in between. As a result, braking with mechanical disc brakes can feel less precise, especially under heavy braking (like with advanced mountain bike trails).
This also leads to the feeling of hand and forearm exhaustion that can accompany a mechanical disc brake system, not to mention a lack of control and confidence for more difficult routes.
Hydraulic Disc Brakes
It bears repeating that hydraulic disc brakes offer top-of-the-line modulation, giving you a smooth, gradual, natural feeling when braking that can drastically improve your precision and confidence. It’s not only smoother, it’s also more consistent—which, again, is an important consideration for avid mountain bikers or high-speed cyclists.
If you often ride in technical conditions where precise control is crucial, the intuitive feel of hydraulic disc brakes can truly elevate your riding experience.
Choosing the Right Type of Disc Brake for You
As with so many things in the world of biking, there’s no clear answer as to which type of disc brake is “better.” It all depends on each individual cyclist and their specific preferences and riding style. Here are some important considerations to keep in mind:
- Riding style: Do you love tackling the gnarliest, most extreme MTB trails? Or are you more of a casual commuter who sticks to flat trails and bike lanes most of the time? If you’re the former, you’ll need a hydraulic disc brake system that allows you to stop on a dime, modulate your braking power, and handle whatever curves and obstacles the toughest trails throw at you. But if you won’t be facing steep hills and switchbacks, and if you’re not trying to set any land speed records, a mechanical disc brake system should suit you just fine.
- Performance: Related to the “riding style” category, you’ll need to decide what level of performance you need from your bicycle’s brakes. Even if you’re riding mostly on city bike lanes or gravel trails, maybe you want the comfort and confidence that comes with unparalleled braking power and modulation.
- Budget: For some riders, it’s important to invest their heart and soul (and money) in their ride to create the ideal machine and ensure everything is as fine-tuned as possible. For others, saving some money to stick with gear that’s decent and reliable (but not groundbreaking) is enough. You do you!
- Maintenance: Simplicity can be a beautiful thing—especially if you want to deal with repairs as little as possible. If so, you may want to stick with mechanical disc brakes, which are basic enough to require very little maintenance (and any maintenance that is needed can often be done at home with standard bike tools). Just keep in mind that if you have hydraulic disc brakes and they need to be “bled” or adjusted in any way, you’ll likely need to take it into a bike shop (like your local ERIK’S!).
As usual with cycling, it’s a good idea to stop into an ERIK’S location and give a few different bikes a try—preferably at least one with both mechanical and hydraulic disc brakes. That will help you get a feel for the braking power and modulation, not to mention the aesthetic design of bikes with both systems (no small consideration).
Finally, look ahead to the future and consider what your biking needs might be a year or two from now. If you’re planning on upgrading your ride in the near future, or you’re thinking about improving your mountain biking skills, a hydraulic disc brake system is probably the way to go.
Shop Mechanical and Hydraulic Brake Options at ERIK’S
ERIK’S stocks the components you’ll need to repair or replace your bicycle’s disc brakes, whether they’re mechanical or hydraulic, including rotors, brake pads, levers, and more. If you need new cables for a mechanical disc brake system or hoses and adapters for a hydraulic system, we have those too! Browse our online inventory or see what brake products we have in-store and upgrade your bike’s most important safety features today.
You can also check out a fun and helpful video about the basics of bike braking. If you’re having trouble setting up a new braking system, we have a helpful blog post and YouTube video about how to “bed in” your new disc brakes.
Of course, if you have any other questions about disc brakes (or anything else bike, board, and ski-related), stop into your local ERIK’S for fast, friendly, expert assistance! We offer a full lineup of brake services at ERIK’S to help you ride safely and confidently, no matter what.
Frequently Asked Questions (FAQs)
What’s better, mechanical or hydraulic disc brakes?
It’s impossible to say which kind of disc brake is “better,” since the answer will depend on each individual cyclist’s preferences and riding style. Hydraulic disc brakes are generally seen as the superior option, thanks to their increased stopping power, high-end modulation, unmatched performance, and smooth, natural braking feel. But cyclists who are just starting out, want to save money, or avoid frequent maintenance may find mechanical disc brakes preferable, especially if they typically ride on flat trails or in the city on road or commuter bikes.
What type of brakes are best on an e-bike?
Due to e-bikes’ heavier weights and potential for higher speeds, it’s important to have the safest, most reliable brakes possible. That’s why hydraulic disc brakes are preferred for electric bicycles—they add to the smooth, effortless feeling of e-bike riding. That said, mechanical disc brakes might still be suitable on certain e-bike models.
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