A fork end,fork-end,or forkend is a slot in a bicycle frame or bicycle fork where the axle of a bicycle wheel is attached. A dropout is a type of fork end that allows the rear wheel to be removed without first derailing the chain.
Track bicycle frames have track fork ends, on which the opening faces rearwards. Because they do not have dropouts, the chain must be derailed from the sprocket before the rear wheel can be removed from a typical track bike. Some single-speed bicycles intended for street or trail use are also equipped with track fork ends instead of dropouts.