Mechanical Vs Hydraulic Disc Brakes – How Are They Different?

Written By, Perry Knight
Last Updated:

Disc brakes, just like the name, it shapes like a disc attached to your bike’s wheel. Did you know that there are apparently at least two types of this kind of brake?

Yep, I said it. There are at least two types of disc brakes, hydraulic and mechanical. If you are planning to get a new bike or upgrade your brakes, you should know what these two are.

And for that reason, we’ve got your back through this article. We’ll guide you to understand more about the difference between the two types of disc brakes.

The Rising Popularity of Disc Brakes

To begin this article, let’s get ourselves a little more understanding of the disc brake itself.

I believe that we’re all already familiar with the rim brake that clams our rim to gradually reduce the bike speed and then stop it. 

Starting with mountain bikes, the disc brakes have made an appearance to the cycling world to provide more braking performance. With the appearance and how it works almost like the modern motorbike bikes, the disc brake sure didn’t take too long until it now became a necessity among cyclists. Though, there are some controversies along the way.

How it reached the popular market like today is likely because the pros are using it then the others just follow it and make it a new trend. From one manufacturer to the other manufacturers, disc brakes have surely been getting more common each day.

Even though in terms of performance the brakes aren’t all-powerful at all, it still provides a more braking performance than rim brakes.

The Concept of How The Disc Brakes Work

Now that we’ve known the existence of disc brakes, how do they work exactly?

Just like any type of brakes, the disc brake gradually slows down your bike when you pull the lever. As the lever is pulled, the brake system applies friction to the braking surface, which is the disc in this case.

The more you pull the lever, the more strength it applies to the braking surface hence, the more stopping power.

Like I said earlier, the disc brakes apply friction to the disc, a small rotor in the middle of the wheel, instead of the rims. 

What makes it different from rim brakes is that the disc brakes provide more control before locking up. They also provide you with more braking range, so you won’t likely skid when braking.

Mechanical Disc Brakes

Okay, let’s talk about the mechanical disc brakes first. 

The mechanical brakes might be the most common type of brakes out there and they’ve been out there in the market as long as we can remember. And now it also comes with disc brakes.

The most apparent characteristic of the mechanical brakes is that they are using cables to operate.

How It Works

Now we’ve covered how the mechanical disc brake generally is, but now we will dive deeper on how it works to put your bike to stop.

In a mechanical disc brake, you engage the steel cable by pulling the lever as this creates a motion that will create the friction between the brake pads and the rotor. The resistance that’s happening in the rotor will eventually stop the bike from moving.

And that’s just basically how it works. But let’s dig a little bit deeper.

If you are used to the rim brakes, you must’ve been aware about how messy it can get after hours and miles of cycling. Well, a few words of warning, it’s the same with mechanical disc brakes here.

They have some openings on the design, thus tend to collect dirt and debris which will be the cause clogging on the system over time. And you know what it means? Your braking will be sloppy and become less smooth, losing the stopping power and the ability to control your bike’s speed.

But, here’s the catch. Because of the said design in mechanical brakes, they are proven to be easier to use and maintain. When you get your brake cable like that, you can just clean it or change it into a brand new one, tighten the lever if you think it’s needed, and you’re basically done with it.

Mechanical disc brakes require frequent maintenance, which can be a hassle sometimes. You have to clean the brake pads and adjust it, just like how you’d do with classic rim brakes, which can take lots of time. But nothing is more satisfying than getting all things done by yourself and it works like you wanted. 

Pros of Using Mechanical Disc Brakes

Using the mechanical disc brakes does come with some advantages with it. Here are a few aspects that you might want to consider if you are getting yourself some disc brakes:

  • The design is pretty much simple and really easy to use and get familiar with.
  • They are more cost effective compared to the hydraulic counterparts.
  • Good for beginners who just entered cycling. 
  • Cheaper parts and easy to find.

Cons of Using Mechanical Disc Brakes

To be fair, we’ve also concluded some of the disadvantages of this type of disc brakes:

  • Compared to hydraulic, they can be heavier
  • They are somewhat difficult to maintain to be on the best performance.
  • Easily damaged from the friction between the cable and the housing. 
  • Needs more pressure to get the bike to stop. 
  • Not as responsive nor sensitive as their hydraulic counterparts.

Hydraulic Disc Brakes

We’ve talked about the classic mechanical system that uses cables to operate and apply pressure to the braking contact point.

Taking into perspective, the hydraulic disc brakes can be said as an upgrade from the classic mechanical system. You may think that these types of brakes are expensive, but their performance would surely speak for the price itself.

To make it brief, the hydraulic brakes provide you with efficiency to control your bike with how almost effortlessly you can stop your bike.

How It Works

In this type of brakes, they are not using the cables anymore, instead they are using the fluid-filled system.

Don’t worry. Even though they get rid of the cables, you still have the lever to apply pressure to the disc that will eventually stop your bike. Instead of pulling the cables, when you pull the brake lever, the fluid will force the pads to go against each other with the rotor between them.

In this type of brakes, the fluid is both housed in the system and in the master cylinder in the lever body. The fluid on the master cylinder will be pushed to the system causing some pressure which acts as the agent that makes the brake pads tighten.

Because liquids are pretty much incompressible, the power of the pressure that is applied to the rotor is greater than the pressure on the lever. This aspect right here that makes hydraulic brakes do better than their mechanical counterparts.

In other words, these hydraulic brakes are quite sensitive and more responsive than mechanical brakes. A gentle push on the lever should give you enough stopping power.

One other thing that you want to note about this braking system is that it’s closed design. This means you won’t get any kind of dirt, water, or debris entering your system that will hinder the performance of your brake. This is pretty good, especially if you are riding in wet weather.

Pros of Using Hydraulic Disc Brakes

Now that we’ve discussed how the braking system works, we can talk about what makes this braking system good.

  • Smooth and responsive braking system.
  • More stopping power with less force a.k.a. efficient.
  • Easy on the hand because you don’t need to pull the lever hard to stop.

Cons of Using Hydraulic Disc Brakes

As usual, to make it fair, let’s also talk about what would make you discouraged to get this type of disc brakes.

  • The system is more complex than mechanical brakes.
  • More difficult to adjust.
  • Both the item and the parts are expensive.

A Comparison Between Two Types of Disc Brakes

Now that you’ve already known about both types of disc brakes in general, let’s compile all the things we’ve got and compare them so that it would be easier to see it.

In general, we’re going to look at a few different aspects of the bike in order to make this comparison. Which can be seen like this:

AspectHydraulicMechanical
Brake MediumFluidCables
WeightLighterHeavier
Brake PerformanceSmoother, more sensitive and responsiveLess sensitive and require more force
AdjustmentComplex and more difficultA lot more easier
MaintenanceAlmost none requiredFrequently
PriceNot as cheapCheaper

The Maintenance of Disc Brakes

Maintaining disc brakes, whatever the system they use, are almost basically the same. Aside from the braking systems themselves, you’ll only have the rotor, the brake pads, and the calipers to be worried about. 

Let’s start with the rotor. Rotor probably the most noticeable feature of a disc brake system, it has disc shape after all. For maintenance of this particular part, you just need to make sure that it’s always clean and dry. Free from any form of liquid, oil, or even dirt. Getting them contaminated with alien substances would make the brakes perform less than what they are actually capable of.

If you are, by chance, happening to do maintenance on the other parts that are near the rotor, be sure to take the wheel off to make it easier. Or, you can take off the rotor if you want to clean the wheel sets.

Next is the brake pads. Same with the rotor, you also need to keep it clean, away from alien substances. You also need to make sure that your brake pads are at least 1mm thick. You can stack about 3 business cards and put it on the side of your brake pads to gauge the thickness of your brake pads. If it’s any lesser than that, well, time to get some replacements.

If you are using hydraulic disc brakes, you might want to consider taking off the brake pads when you are “bleeding” your system, we’ll talk about this more later.

Another part that is almost basically the same with either bike you are using is the caliper. You need the caliper to be in the right position so that it won’t unnecessarily rub the rotor. 

There is a simple hack for this. Because the disc brakes are pretty much self-adjusting, you just need to pull the lever until the brake pads are going against the rotor then loosen the caliper screws. With this, the calipers are able to move then you just need to correct the position and tighten the screws back. Voila! You get it corrected.

You also want to note that you shouldn’t ever pull the lever when you take the wheel off because it would make the gap closing on the pads which would later might result in another problem. You can opt to either lock the lever or put some business cards or a coin to fill the gap between the brake pads.

  • Mechanical Disc Brakes Maintenance

Now let’s talk about mechanical system specific maintenance. Honestly there isn’t much to talk about this because it’s pretty simple and straightforward.

We’ve already known that mechanical systems require more maintenance since they are using cables in an open design which can be an invitation to any alien substance.

Because of that you need to frequently check the cables for its tension, cleanliness, and also the lube.

Always make sure that there is no damage on the steel-braided cable that you are using. If you find any damage while inspecting it, time to change it with the new one. And when you are installing it, don’t forget to lube the cables so that it would cause less friction with the housing which can cause damage to the cable itself.

If you happen to feel like your brakes are spongy or require more force to get the job done, you can simply tighten the cables. This is usually caused by worn brake pads. So to tighten the cables you just need to roll the barrel adjuster near the brake lever.

  • Hydraulic Disc Brakes Maintenance

In the process of maintaining hydraulic disc brakes, we have a process called bleeding. Yep, we are going to literally bleed the system with specific fluid. You need to take a note that different brakes from different manufacturers might require different types of liquids too.

To do the bleeding process properly you might need to use a bike stand because the bleeding points, that are inside the caliper, should be lower than the lever . If you don’t have a bike stand, there is actually a hack for this. Just remove the calipers from your bike, it will ensure that the bleeding point will be lower and you can make the liquid system flow better. Also, don’t forget to take off the brake pads to save it from excess fluid.

When you get the preparation step done, you need the bleeding specific equipment like a syringe, hose, hose locker, and bleeding funnel/bucket.

Pour a little liquid to the bleeding funnel, around ⅓ of it is enough, open the dust cap on your brake lever then screw the funnel in. Be sure to unplug the plunge to make the liquid can flow into and out from the system. You will also be able to see the air that infiltrated the system through this way.

Take out your syringe, attach the hose, and fill it with the fluid to bleed your system. When you get enough of the liquid, put on the hose locker near the receiving end of the hose.

Open the dust cap on the bleeding point and attach the hose to it. Be sure that you lock the hose by moving the hose locker to the contact point of the hose and the bleeding point. Unscrew the bleeding screw and inject the liquid to the system.

You can see the excess liquid surfacing on the bleeding funnel, as well, as some bubbles of air. You might want to flick the housing a few times to let the air move out of the system.

Note: you don’t need to do this maintenance too often. Just do it when you feel that your brakes are getting spongy or just don’t perform well. We’ve discussed that this braking system doesn’t need much maintenance after all.

Features Worth Noting About Disc Brakes

We’ve discussed almost everything about disc brakes, especially the comparison between hydraulic and mechanical disc brakes. But there are few more things that you might want to know about this specific type of brakes.

Safety

When disc brakes were introduced to pro cycling as well as the market, a few controversies sparked. Like any new things, there will always be pros and cons regarding it.

In this case, the most apparent controversy is the safety. Is it safe to be used in a peloton of pro cyclists or in the daily road. Most concerns are emerging from the heat that is resulted from the braking action between the rotor and the brake pads.

This kind of buildup heat would surely cause a braking power loss at some point. Not only that, this can also cause harm to other riders when riding on a group.

A recent measure that was made to this type of brakes is the manufacturers are starting to layer the rotor into part aluminium and part stainless steel. The aluminium part on the inside of the rotor would ease up the heat distribution and improve cooling.

Mount Compatibility

If you are planning to upgrade from rim brakes to disc brakes, you need to know that you most likely can’t use your old wheel and fork, even the frame itself.

Some of the modern consumer bikes might have provided the frame and with switchable capability between traditional rim brakes and disc brakes. So you might want to check out your bike again before you decide to purchase the disc brakes.

The disc brakes need a special mount on the fork and the frame to attach themselves to the bike. They also need a special hub where the rotor will reside at.

Disc Brake Vs Rim Brake

Oh, you might even still have these kinds of debates even now. Rim brakes vs disc brakes, which are better?

Objectively speaking from the performance point of few, disc brakes can be said aced everything and get better marks than rim brakes.

But there are some other considerations, from the added weight of the disc brakes, to how it can be visually unappealing to some people compared to rim brakes.

From the maintenance point of view, the rim brakes are a lot more easier to do than the disc brakes. Not to mention that rim brakes are also cheaper than the disc brakes.

So if you are in a conflict with yourself, be sure that you consider all the points we’ve talked in this article to decide which one is for you.

Which is It for You? Hydraulic or Mechanical?

On deciding which one is for you, we need to look at the most basic thing, the budget. Not gonna lie, if you are on a tight budget and you want to get yourself disc brakes, you might want to opt for the mechanical ones instead of more expensive hydraulic ones.

If you have more budget, you can look at the hydraulic options.

But if you are more of a long-term investment person, I would recommend getting your hands on the hydraulic disc brakes. They are easy to use, safe, require a very little maintenance and just a lot better than the mechanical counterparts.

Even though i said like that, the actual experience might not feel really different, when you are used to your mechanical brakes, you might want to stick with it because it’s more comfortable. Changing your braking system might feel awkward when you actually experience it.

So, pick which one is the most suitable for you from any perspective.

Similar, But Completely Two Different Things

Both mechanical and hydraulic disc brakes might look similar from the first glance. But if you look closely they are quite different.

Both braking systems have their own advantages and disadvantages when brought into perspective. From the performance, maintenance, how it works, and even the price, they are different and from different classes too.

With all the considerations we’ve discussed up until this point, I hope you could find which one is the most suitable for your ride.

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Author
Hello, my names Perry and I've been a freelance writer for the past 5 years and a cycling enthusiastic since I can remember. I love the road, but my main passion is mountain biking.

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