Mechanical vs Hydraulic Disc Brakes Everything You Need to Know
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Mechanical vs Hydraulic Disc Brakes: Everything You Need to Know

Deciding on a new bike is a big decision, but it might feel intimidating if you don’t understand the technical jargon. Something as essential as the brakes can be confusing, but we are here to help you understand the difference between mechanical and hydraulic disc brakes.

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Mechanical vs Hydraulic Disc Brakes

Contrary to popular belief, bicycle brakes are not all the same. The brakes on your bicycle or the ones you will eventually buy are either disc or hydraulic. Though most people assume these two types of bicycle brakes are fairly similar, the truth is there are significant differences between the two. If you are interested in how your current bike’s brakes work or if you are considering buying a bike, you have surfed the web’s digital waves over to the best source of information. Let’s take a look at mechanical vs hydraulic disc brakes.

Bicycle Braking System Functionality

Each type of bicycle brake functions with the application of pressure to the brake handles. The pressure applied to these handles forces the brake pads to move along the surface on the bike wheel to generate friction that slows down the bike. However, the location of this friction is one of the key differences between the different types of brakes. The mechanical disc and hydraulic disc brake rotors both connect to the hubs of the bike, causing the wheels to spin.

The brake pads are mounted within the brake calipers that are mounted by the axles either in the chainstay, seat, or fork. The rotor spins in between these pads during the cycling motion. The brake system’s calipers hold a mechanism that moves the brake pads against the rotors through a piston that functions with the squeezing of the levers positioned by the handlebars. The resulting friction between the rotors and pads forces the bike to slow.


Mechanical vs Hydraulic Disc Brakes

Before we dig into the merits and drawbacks of mechanical disc brakes, let’s take a look at the primary differences between mechanical disc brakes and hydraulic brakes. The main difference between these two types of braking systems is the manner in which force is sent from the brake levers on the bike’s handlebars to the brake calipers along the hubs. Mechanical disc brakes rely on a steel cable for functionality.

Alternatively, hydraulic disc brakes rely on a brake line that is filled with fluid for functionality. The squeezing of a hydraulic disc brake lever causes a plunger to push the brake fluid through the master cylinder’s lever body to the brake line. This line is sealed and contains fluid, generating pressure along the line. The pressure forces the brake caliper piston to push the brake pads toward the rotors, largely because fluids do not compress. This design is similar to that used on the disc brakes used in motorcycles and automobiles.

Are Mechanical Disc Brakes Good?

Let’s shift our attention to the pros and cons of mechanical disc brakes. This type of bicycle braking system has an inherent appeal to bike manufacturers, merchants, and bike riders alike as it is comparably affordable. Mechanical disc brakes are also favored as they can be maintained and repaired comparably easily.
The design of mechanical disc brakes is that much simpler than hydraulic bike brakes, ultimately making repairs faster, easier, and less frustrating. Add in the fact that replacement parts for mechanical disc brakes can be found with ease, regardless of the bike rider’s location, and the appeal is that much greater. Mechanical disc brakes can be easily serviced with basic tools by bike specialists and even those who embrace the DIY (do it yourself) mantra.

There are also some drawbacks to mechanical disc brakes. This type of bike brake does not provide the same stopping power as hydraulic braking systems. Those looking for reliable stopping power when bike packing or touring are likely to be quite content with a bike that has a mechanical disc brake system. Those who bike for other purposes tend to be partial to hydraulic disc brake systems. Furthermore, mechanical disc brakes are comparably inefficient. If your primary concern is stopping at a reasonable distance in a short amount of time, mechanical disc brakes are not ideal. Furthermore, this type of bicycle brake makes the modulation of braking force challenges. Veteran bicycle riders are also quick to testify to the fact that mechanical disc brakes have more of an on/off feel that isn’t as fluid as that provided by hydraulic bike brakes.

Another negative to mechanical disc brakes is that they require adjustments that much more frequently as their cables tend to stretch more than others. It is also possible for friction within the brake lines to make mechanical disc brakes somewhat rigid during operation, ultimately rendering them less consistent than those of the hydraulic variety. If your primary concern is minimal maintenance and cleaning, you should know mechanical disc brakes require cleaning at a higher frequency as the lines tend to become contaminated with debris, dirt, and other gunk that much more often than hydraulic systems. It is also worth noting those who have arthritic fingers and/or arthritic hands find that applying mechanical disc brakes requires comparably more force.

In short, mechanical disc brakes are not as technologically advanced as hydraulic disc brakes. The lack of complexity isn’t necessarily a problem unless you want the best possible braking system on the market, regardless of cost and other factors. The simplicity of the mechanical braking system is evidenced by the fact that it functions with the use of stainless steel cables positioned between the caliper and lever. This basic design is ideal for repair and maintenance as you can easily find replacement inner/outer cables regardless of your location and change them on your own. However, the mechanical braking system does not function as fluidly as that of the hydraulic variety.

Opt for mechanical disc brakes and you will agree they are a bit annoying as they tend to rub against one another when not perfectly adjusted. Though you can maintain this type of bicycle braking system on your own, doing so will chew up your time as they require that much more attention than those of the hydraulic variety. However, if you were to poll experienced bicyclists, you would find mechanical disc brakes are suitable for the majority of touring applications. You can ride in full confidence while atop a bike with mechanical disc brakes, even when venturing out to remote areas, without even the slightest worry of the system failing you when you need it the most.

Are Hydraulic Brakes Good?

Hydraulic brakes provide superior stopping power, proving that much more efficient than mechanical disc brakes. Hydraulic brakes do not require maintenance or adjustment at the same frequency as others. This type of bicycle brake self-adjusts, meaning maintenance is not necessary nearly as frequently as required by mechanical disc braking systems. Hydraulic brakes are a sealed system, meaning contaminants cannot move inward, ultimately reducing the frequency of cleaning. The comparably minimal friction in hydraulic braking systems allows for smoother operation along with superior control over the level of braking force applied. Those who have arthritic fingers also favor hydraulic brakes as they do not require as much force for operation as those of the mechanical variety. This heightened sensitivity is also favored by those who enjoy riding fast as a light tapping of the brakes allows for a timely stop.

Though hydraulic bike braking systems are clearly technologically advanced, they are not without their flaws. The downsides to hydraulic brakes include a higher cost, greater maintenance difficulty due to the complexity, and the challenge of finding spare parts in certain regions. It is possible for hydraulic disc brakes on the higher end of the price spectrum to run $300 to $400 for a set. Those on the lower end of the price spectrum are likely to run at least $100. This type of bike brake also costs that much more in the context of maintenance.

As an example, paying a bike shop to bleed hydraulic brakes has the potential to cost upwards of $100. Though bleeding hydraulic brakes is only necessary once per year or two, the cost will add up over time unless you learn how to bleed your bike’s brakes on your own. Bleeding a bike’s brakes is the replacement of the brake fluid. In general, hydraulic bike braking systems require bleeding once every two to three years. However, it might be possible to go half a decade without a bike braking system bleed. The frequency of your rides plays a large part in the necessity for such bleeds. If you participate in bicycle races with regularity, it might be necessary to replace the brake fluid once per year or even sooner to ensure the brakes function as designed.

Even the type of fluid used for the brakes plays a role in the frequency of bleeding hydraulic disc braking systems. Every bike rider should also be aware that a hydraulic braking system will also require bleeding after the brakes leaked or were opened, regardless of the specific reason for that opening. Fail to bleed your hydraulic braking system after an opening and there is the potential for air bubbles to form within the system, ultimately compromising the braking power.

Every prospective bicycle buyer should be aware that hydraulic bike braking systems are comparably difficult to maintain. Specialized fluid and tools are necessary to bleed and otherwise service hydraulic bike brakes. You can master this learning curve on your own as long as you are willing to buy the tools necessary for bleeding the system. At a bare minimum, you will need a bleed block that keeps the pistons in the right position, adapters, pliers, Allen wrenches, a screwdriver, and syringes.

If you are a casual bike rider who heads out for the occasional spin, hydraulic brakes might not be ideal. Those who take biking seriously and regularly hit the pavement for biking expeditions are quick to sing the praises of this unique type of brake. However, it must be noted there is the potential for hydraulic disc brakes to leak. If the seal fails, the brake fluid will start to leak out of the line and potentially reach the rotors and brake pads. Once the brake pads are soaked in brake fluid, they will fail to function and might require replacement.
The leaking fluid even has the potential to damage the surface of the brake pad. If the brake fluid extends to the rotors, careful cleaning will be necessary so be sure to remove all of the fluid prior to reinstallation.

Hydraulic brake pads also pose a risk as there is the potential for their pads to become stuck together or even for the pistons to protrude out too far. An accidental squeezing of the brake lever when the wheel is off of the bicycle prevents the rotor from serving as a spacer that holds the brake pads apart from one another. If you find the pistons of your hydraulic brakes emerge too far at the point when you apply pressure to the brake lever, remove the pads then push them back inward.

How Long do Mechanical and Hydraulic Disc Brakes Last?

In general, hydraulic disc brakes tend to last longer than mechanical disc brakes. However, the same rotors and pads are used in both mechanical and hydraulic disc brakes. These parts require replacement as time progresses. In particular, the pads of mechanical brakes require periodic replacement. This replacement is necessary due to the friction generated when the pads and rotors rub against one another.

The length of time your mechanical disc brakes last ultimately hinges on the material the pad consists of along with the pressure exerted when braking, the terrain you ride on, and the conditions you ride in. If the mechanical disc pads are organic pads, they have the potential to last upwards of 800 miles. In contrast, sintered brake pads typically last 1,000 or more miles. If you notice there is merely 1 mm of brake surface remaining on the pads, be proactive and replace them right away. The timeliness of maintenance as well as the quality of pads and rotors also shapes the longevity (or lack thereof) of your mechanical disc bike brakes.

When in Doubt, Err on the Side of Safety

Above all, what matters most in the context of riding your bike is safety, health, and well-being. If you are still on the fence as to whether a bike with a hydraulic disc braking system is better than one with a mechanical disc braking system, lean toward the design with superior safety. After all, you won’t be able to continue enjoying peaceful bike rides while soaking up the beauty of your natural surroundings unless you are healthy enough to do so.

In terms of safety, the bike’s braking system’s stopping power matters more than anything else. Hydraulic disc braking systems generate superior stopping power. Those who find their attention slipping while riding as they take in the aesthetics of the trails or other space gravitate to hydraulic disc brakes as their efficiency provides superior stopping power. Hydraulic bike brakes multiply the force applied to the braking system at the point when the brake lever is initially squeezed. In plain terms, this means the hydraulic brakes generate additional braking force than that applied by the rider’s hands to the braking lever.

Hydraulic disc brakes are also favored by bike riders who desire the safest possible riding experience as this system’s brake fluid does not compress. The lack of compression combined with the comparably less friction transmitted through the line results in the loss of as little energy as possible. The engineering masterminds behind this unique design deserve credit for creating a powerful braking system that requires minimal effort for operation.

Alternatively, mechanical disc bike braking systems are not as efficient as those of the hydraulic variety. The inferior efficiency results from comparably less force moving from the braking lever to the system’s caliper. This design causes energy to be lost when the rider applies pressure to the braking lever. The pulling of the brake lever causes part of the force applied to be redirected to offset the friction generated by the cable as it moves through the system’s housing.

This process results in lost energy as the cable compresses/stretches. The brake pads are not capable of pushing along the brake system’s rotors at the force necessary to generate the same level of friction created by hydraulic disc braking systems. The resulting lack of power causes the stopping distance to be extended that much more, rendering the rider more prone to a potentially painful collision with an automobile, a fellow bicyclist, or another object.

In summary, those looking for a new bike that is designed with rider safety in mind should choose one with a hydraulic disc braking system. When in doubt, consult with a bicycle industry expert or an experienced bicyclist with decades of experience for additional guidance.


What Brakes Do Major Bike Brands Use?

With all of this understood, it might also help to understand where you might find hydraulic brakes or a mechanical brake system. If you are looking for a basic cruiser bicycle, you are more likely to find a basic mechanical brake system with a simple side-pull brake caliper.

On the other hand, advanced road bikes, such as the Specialized Roubaix and Trek Domane advanced-design flat mount hydraulic brakes. There are many different types of disc brakes, but the reality is that most competitive bikes use hydraulic disc brakes with hidden cable systems. In years gone by, professional cyclist teams may have chosen rim brakes, because the wheels were easier to change if there was a blown tire. In endurance races such as Paris-Roubaix for Flanders, a blown tire is more common than you might realize, but manufacturers no longer use traditional rim brakes and have opted for hydraulic brakes instead.

The advantages of cable-actuated hydraulic disc brakes are clear. We mention the Roubaix and Domane above because those looking for a competitive bike often make a decision after comparing Trek vs Specialized. While those looking for an endurance road bike might decide after comparing the Domane and Roubaix, those looking for a full-suspension mountain bike are likely to compare Trek Fuel Ex vs Specialized Stumpjumper.

Specialized and Trek both make great bikes, but of course, there are plenty of other great brands out there. Regardless, bicycle disc brakes are most often of the hydraulic variety on competitive bikes. That isn’t to diminish mechanical disc brake bikes, but they are often cheaper, and better suited for cruising around town, or up and down the beach. If you plan racing competitively, chances are you need hydraulic brakes.

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