Modern bicycle brakes may be: rim brakes, in which friction pads are compressed against the wheel rims; internal hub brakes, in which the friction pads are contained within the wheel hubs; or disc brakes, with a separate rotor for braking. Disc brakes are more common for mountain bikes, tandems and recumbent bicycles than on road-specific bicycles, due to their increased weight and complexity.
With hand-operated brakes, force is applied to brake levers mounted on the handlebars and transmitted via Bowden cables or hydraulic lines to the friction pads, which apply pressure to the braking surface, causing friction which slows the bicycle down. A rear hub brake may be either hand-operated or pedal-actuated, as in the back pedal coaster brakes which were popular in North America until the 1960s.
Track bicycles do not have brakes, because all riders ride in the same direction around a track which does not necessitate sharp deceleration. Track riders are still able to slow down because all track bicycles are fixed-gear, meaning that there is no freewheel. Without a freewheel, coasting is impossible, so when the rear wheel is moving, the cranks are moving. To slow down, the rider applies resistance to the pedals, acting as a braking system which can be as effective as a conventional rear wheel brake, but not as effective as a front wheel brake.
