Cycles of all sorts

Drum brakes are used mainly on bicycles which are operated in wet or dirty conditions. Though heavier, more complicated, and frequently weaker than rim brakes, they require much less maintenance and are less affected by road conditions. Both cable- and rod-operated drum brake systems have been widely produced. While most common on utility bicycles in certain countries, especially the Netherlands, they are also frequently found on freight bicycles.

A bicycle drum brake's operation is identical to that of a car's with the exception of the absence of a ratching adjustment mechanism and hydraulic actuation. Two pads are pressed outward against the braking surface on the inside of the hub's shell, which is packed with grease. Shell diameters on a bicycle drum brake are typically 70 - 120 mm. Drum brakes have been used on front hubs and hubs with both internal and external freewheels.

A common design of drum brake is the Roller Brake, manufactured by Shimano. This is a modular cable-operated drum brake for use on specially splined front and rear hubs. Unlike a normal drum brake, the Roller Brake can be removed entirely from a hub, allowing it to function as a regular freewheel. It also contains a torque limiting device which reduces its effectiveness on bicycles with adult-sized wheels.

Drag brake

In addition, drum brakes are also installed on some tandems used in mountainous areas as a so called drag brake. In this application, the drum is not intended to stop the bike but, rather, to keep the speed down on long downhill sections where extended use of rim brakes can cause the tire to become hot enough to explode.

The largest manufacturer of this type is Arai, whose brakes are screwed onto hubs with conventional freewheel threading on the left side of the rear hub and operated via Bowden cables.