Hydraulic vs Mechanical Disc Brakes: Debunking the Myth of Mountain Bikes
When it comes to mountain bikes, the terms 'hydraulic disc brakes' and 'mechanical disc brakes' are often used interchangeably. However, there is a common misconception that hydraulic disc brakes are purely mechanical systems without any hydraulic components. This article aims to clarify the differences and explain why 'hydraulic disc brakes' is the correct term for the vast majority of contemporary mountain bikes.
Understanding Hydraulic Disc Brakes on Mountain Bikes
Most mountain bikes on the market today feature hydraulic disc brakes. These systems are not purely mechanical; they do in fact incorporate hydraulic actuation. The hydraulic system is hidden within the brake lever assembly and the pipe connecting the lever to the caliper. This hidden component makes it easy for those unfamiliar with the technology to mistakenly believe that the brake system is purely mechanical.
The Hidden Hydraulic Components
The key to understanding hydraulic disc brakes lies in their hydraulic reservoir, which is usually built into the brake lever assembly. The hydraulic fluid is contained within a flexible hose connecting the lever to the caliper. When the rider depresses the brake lever, it activates a master cylinder, which forces fluid to expand the caliper, thus squeezing the brake pads against the rotor. This process is what defines a hydraulic disc brake.
Comparing Mechanical and Hydraulic Disc Brakes
It is worth noting that there are indeed two distinct types of disc brakes used on mountain bikes. The most common type is the hydraulic disc brake, which incorporates the aforementioned hydraulic actuation. In contrast, there is the mechanical disc brake, which uses a cable to transfer the brake lever's movement to the caliper. This mechanical system does not involve any hydraulic fluid.
Common Misunderstandings
There are a couple of reasons why this misconception may arise. Firstly, it could be due to a lack of understanding of the technology. Many riders might not realize that the brake system is hydraulic because the components are not immediately visible. Secondly, it might be due to the presence of a mechanical disc brake system, which is correctly described as such. If the rider is examining a system with a clear cable, they should be referred to a cable-operated or mechanical brake.
Examples of Hydraulic and Mechanical Brakes
Many riders might have experienced both types of braking systems. For instance, the manual BB7 system, which is quite common on many mountain bikes, is a mechanical system. However, some riders might have upgraded to a more advanced hydraulic system, such as the SHIMANO hydro brake, which uses mineral oil and an upgraded disc brake system.
Conclusion
While it is understandable why the term 'hydraulic disc brakes' can lead to confusion, it is indeed the correct term for the vast majority of contemporary mountain bikes. Hydraulically actuated systems are the standard, and riders who are unaware of this technology should take a closer look at the calliper to determine the type of brake system in use. Quality mountain bikes typically feature hydraulic disc brakes because of their superior performance and stopping power. Whether you choose a manual system like BB7 or an upgraded hydraulic system, understanding the differences can help you make a more informed decision when choosing your next mountain bike.