The installation of disc brakes on the bike is made from metal disc attached to the wheel of the bike, the lock pliers fixed to the frame and the lever assembly mounted on the handlebar, and of course, the cables transmitting the braking system from the lever’s calipers / pads / discs.
In hydraulic disc brakes, the braking force is transmitted through the oil in the brake system acting on the piston pliers to tighten the pads on the disc, while the mechanical disc brake calipers are actuated through the cable pulled by levers on the handlebars.
Other types of brakes used in the past decades have lost their appeal, from the cantilever to V brakes (V-brakes). Disc brakes have now conquered the market for mountain biking, with some exceptions, thanks to their overall performance. As part of the disc brakes, hydraulic systems have also gotten the better of mechanical ones, mainly due to a much higher stopping power. We can consider the hydraulic disc brakes as standard solution for most of the MTB. Now let’s look closely at the main components of this braking system.
Mountain Bike – Disk
The characteristics of calipers and pads affect the power of the brakes, but they are the size of the disk to make a difference. With larger disks, it has a greater effect on the wheel, reaching more quickly a full braking. According to some, an increase of 20 mm in diameter of the disk is equivalent to an increase of the braking power which is around 15%.
With regard to the measures, the disks 140 mm is the smallest and the minimum necessary to obtain a decent braking on the rear wheel. The 160 mm rotors are a more effective solution, but only with the higher-end braking systems will be able to get a quick-release rear wheel with these measures. For these reasons today are increasingly used discs 180 mm. For the most demanding MTB disciplines such as downhill, we prefer larger disks, 200 and even 225 mm. Larger disks are heated less and cool more quickly, qualities useful in case of long and challenging runs, where the braking system is constantly called upon to do his duty to the fullest. The downside is given by the weight higher and more stringent requirements for forks and frames.
Generally made of aluminum alloy and steel, the discs are made from a continuous block of metal but more like a sort of central star connected to a shaped edge and perforated. The reduction of the amount of metal solutions and design specifications allow to decrease the weight, increase ventilation and reduce the accumulation of dirt. A final difference between the various types of discs is given by the system used for mounting on the hub: the two standards are in use the center and lock the system with six screws. In any case, there are adapters that allow you to convert your disks with six holes in center lock.
Mountain Bike – Tablets.
Generate friction pads against the disc on which the braking power of the system: they are a critical component of the disc brakes. In addition to the differences between the different manufacturers, brake pads for disc brakes can be divided into three categories based on the type of compound used to produce the lining, which is the element that makes direct contact with the disk:
- Organic pads – The compound contains natural rubber, resins and polymers. Successful operation in cold and wet weather, ample power, fewer wear on the disc, the shorter duration.
- Sintered pads – compound composed of resins or polymers and metals produced by sintering. Higher hardness than the organic, long life, good resistance to heat, wear and tear of the disc with respect to the intermediate organic compounds and semi-metallic.
- Semi-metallic pads – Ferodo consisting of a mixture of different metals. Excellent resistance to overheating, increased consumption of the disk.
Pliers.
The calipers are the element that transmits the force from the lever on the handlebar to the brake disc on the wheel. As far as hydraulic disc brakes, the pistons in the calipers are housed receiving the impulse from the brake pipe controlled by the lever on the handlebar, commanding the tightening of the pads on the disc to slow or stop the movement of the wheel of the bike. In mechanical disc brakes, calipers are controlled by the traction exerted by the metal cable attached to the lever on the handlebar. Each manufacturer has different technical solutions for calipers and pistons, both in materials used and in the number of pistons, it is obviously in the design of individual parts and the whole of the device.
Levers.
The lever assembly mounted on the handlebar is the tool used to control the braking system. The size and shape of the lever, the material it is made, the position and the ” hardness ” vary from product to product: every enthusiast will find the solution that best fit their driving style and their needs. The lever assembly of hydraulic disc brakes, as well as the lever, the attack on the handlebars and cables (containing the brake fluid), it also houses a reservoir connected with the braking system fluid. The liquid used in the hydraulic disc brake MTB products are designed and manufactured specifically for this use.
Maintenance disc brake MTB.
Periodic cleaning and lubrication of joints and joints help keep the system efficiency. The health status of the brake system should be checked carefully, given the obvious importance of its successful operation for driving safety of the bike. The discs should be visually inspected to verify that they are not dirty, especially oil. In case, if possible It should be cleaned with isopropyl alcohol (available in specialty shops, but also in hardware stores and do-it-yourself), which evaporate without leaving a trace. If they are damaged, chipped or worn parts should be replaced immediately. The same goes for the pads if they are dirty, clean it with isopropyl alcohol, if damaged, worn or glazed, they must be replaced.
Of pliers, group levers and cables occur, firstly, the integrity and functionality (screws and fixings included), in addition to their correct positioning. In case of doubt, it is best to check the brake system to a mechanic. If there are problems with plumbing, you can try to purge any air bubbles that have formed on the inside. In any case, you should always refer to the user manuals and the specific instructions of the manufacturer of your disc brake system for the proper maintenance and use of spare parts and materials suitable.
