A type of
bicycle brake often found on single-speed bikes (those with only one
gear on each wheel, and hence no
derailleurs).
While most hand-operated bicycle brakes work by pinching the wheel rim between two brake pads, the coaster brake is housed in the hub of the rear wheel and activated by moving the pedals backward. It stops the bike by means of a ratcheting mechanism.
Coaster brakes are strong and tend to be more reliable than rim brakes under low-performance conditions, but don't work well at high speeds or on slopes; in these situations they're prone to locking and making the bike's wheels skid. They're most often seen on children's bikes and single-speed "crusiers" common
in coastal areas.