Some hubs have attachments for disc brakes or form an integral part of drum brakes.
* Disc brakes - a disc brake comprises circular plate or disc attached to the hub which is squeezed between brake pads mounted within a caliper that is fixed to one side of the wheel forks. The brake disc can be attached in a variety of ways using bolts or a central locking ring.
* Drum brakes - a drum brake has two brake shoes that expand out into the inside of the hub shell. Rear mounted drum brakes are often used on tandems to supplement the rear rim brake and give additional stopping power.
* Coaster brake - coaster brakes are a particular type of drum brake which is actuated by a backward pressure applied to the pedals. The mechanism is contained inside the bicycle wheel hub shell.
For information on other types of bicycle brakes see the full article on bicycle brake systems.
The rear hubs have one or more methods for attaching a gear to it.
* freehub - The mechanism that allows the rider to coast is built into the hub. Splines on the freehub body allow a single sprocket or, more commonly, a cassette containing several sprockets to be slid on. A lock ring then holds the cog(s) in place. This is the case for most modern bicycles.
* freewheel - The mechanism that allows the rider to coast is not part of the hub, it is contained in a separate freewheel body. The hub has threads that allow the freewheel body to be screwed on, and the freewheel body has threads and/or splines for fitting sprockets, or in the case of most single speed freewheels an integral sprocket. This style of hub was used before the freehub became practical.
* track sprocket - There is no mechanism that allows the rider to coast. There are two sets of threads on the hub shell. The threads are in opposite directions. The inner (clockwise) set of threads is for a track sprocket and the outer (counter-clockwise) set is for a reverse threaded lock ring. The reverse threads on the lock ring keep the sprocket from unscrewing from the hub, which is otherwise possible when slowing down.
* Disc brakes - a disc brake comprises circular plate or disc attached to the hub which is squeezed between brake pads mounted within a caliper that is fixed to one side of the wheel forks. The brake disc can be attached in a variety of ways using bolts or a central locking ring.
* Drum brakes - a drum brake has two brake shoes that expand out into the inside of the hub shell. Rear mounted drum brakes are often used on tandems to supplement the rear rim brake and give additional stopping power.
* Coaster brake - coaster brakes are a particular type of drum brake which is actuated by a backward pressure applied to the pedals. The mechanism is contained inside the bicycle wheel hub shell.
For information on other types of bicycle brakes see the full article on bicycle brake systems.
The rear hubs have one or more methods for attaching a gear to it.
* freehub - The mechanism that allows the rider to coast is built into the hub. Splines on the freehub body allow a single sprocket or, more commonly, a cassette containing several sprockets to be slid on. A lock ring then holds the cog(s) in place. This is the case for most modern bicycles.
* freewheel - The mechanism that allows the rider to coast is not part of the hub, it is contained in a separate freewheel body. The hub has threads that allow the freewheel body to be screwed on, and the freewheel body has threads and/or splines for fitting sprockets, or in the case of most single speed freewheels an integral sprocket. This style of hub was used before the freehub became practical.
* track sprocket - There is no mechanism that allows the rider to coast. There are two sets of threads on the hub shell. The threads are in opposite directions. The inner (clockwise) set of threads is for a track sprocket and the outer (counter-clockwise) set is for a reverse threaded lock ring. The reverse threads on the lock ring keep the sprocket from unscrewing from the hub, which is otherwise possible when slowing down.
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