All mountain bike brakes operate by the same general principal. A lever
is pulled on the handlebar which causes a cable or fluid to compress brake pads
against either the wheel rim or a rotor to slow down or stop the wheel.
The left brake lever always operates the front wheel brake and the
right lever operates the rear wheel.
1. Rim Brakes
With rim brakes, the brake lever is pulled and brake pads are compressed against the
rim of the wheel.
There are several different types of rim brakes, including v-brakes,
u-brakes, cantilever brakes, or direct pull brakes, but you mostly see
v-brakes today.