Disc Brakes - Advantages and Disadvantages

What is a Disc Brake?

A disc brake is a form of braking system that works by using friction caused by the rotation of a metal disc against pads to slow or stop the movement of an object.

The rotating discs act as the braking mechanism and are attached to the wheel hub by means of flexible steel or aluminum springs, or any other appropriate material.

Advantages of Disc-brakes :

1. Continuous braking power, unlike drum brakes that only offer full-force braking with constant application. 
2. They provide the more stopping power and are less prone to brake fade than rim brakes.
3. They are also relatively easy to maintain and repair.
4. Disc brakes work equally well in all weather conditions.
5. Increased stopping power - disc brakes provide more stopping power than traditional brakes, which is especially important when riding in wet or hazardous conditions. 
6. Reduced brake fade - with traditional brakes, the heat created by braking can cause the pads to wear down and/or the brake fluid to boil, resulting in a loss of braking power. Disc brakes produce much less heat than traditional brakes, so they are less likely to experience brake fade. 
7. More reliable in extreme weather conditions - disc brakes perform better in extreme weather conditions (such as rain or snow) than traditional brakes. 
8. Easy to maintain - disc brakes are relatively easy to maintain; you just have to make them.
9. Continuous braking force on the wheel, not pulsatile like drum brakes. 
10. Braking is more gentle on occupants in the car because there is less body motion during emergency stops. 
11. They deliver smoother, more consistent braking performance;.
12. They can be designed to better shed water, debris, and ice for improved wet weather performance.
13. The lifetime cost of disc brakes typically costs less than shoes or pads on a drum brake.
14. Disc brakes generally provide more braking power for a given weight, because the energy can be transmitted at a greater level of force. This is due to the disc's dominance over the maximum amount of pressure that it can withstand. 
15. A brake disc with a rubber pad has an upper limit on how much pressure it can withstand before failing, but this limit is higher than with drums.

Disadvantages of Disc-brakes:

1. Discs give less-varying stopping power as they heat up from use and so they are better suited to long downhill runs as opposed to drum brakes which perform poorly as they heat up.
2. If your wheels lock under braking then the sudden release may result in uncontrolled.
3. Disc brakes are more expensive.
4. They can be heavier than rim brakes.
5. A larger disc means more rotational inertia than stock brakes that could lead to over-slow response or "lockup" with ABS off when driving into bumpy terrain or severe braking events.
6. They also require proportionally strong wheels to handle the forces exerted on them by heavy braking (tires wear out sooner).