Definitions for "DISC BRAKE"
The most popular and effective type of automotive brake. It uses a rotor (a round grey metal plate) which is squeezed by a caliper to create friction and thereby generate stopping power.
Most cars have disc brakes on the front wheels, and some have disc brakes on all four wheels. The main components of a disc brake are the brake pads, the caliper, and the rotor. The disc brake is the part of the brake system that actually stops the car. In a disc brake, the brake pads squeeze the rotor instead of the wheel. (See Figure 5.) Figure 5. Disc Brakes
A disc brake stops the bike by squeezing brake pads against a circular disk attached to the wheel. They can be mechanical or hydraulic.