A drag brake is a type of brake defined by its use rather than by its mechanical design.
A drag brake is intended to provide a constant decelerating force to slow a bicycle on a long downhill rather than to stop it — a separate braking system is used to stop the bicycle. A drag brake is often employed on a heavy bicycle such as a tandem in mountainous areas where extended use of rim brakes could cause a rim to become hot enough to blow out. The typical drag brake has long been a drum brake. The largest manufacturer of this type of brake 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. As of 2011, the Arai drum brake has been out of production for several years, with remaining stocks nearing depletion and used units commanding premium prices on internet auction sites.
More recently, large-rotor disc brakes are being used as drag brakes. DT-Swiss make an adapter to mate disk rotors with hubs threaded for the Arai drum brake, but this still leaves the problem of fitting the calliper.
Famous quotes containing the words brakes and/or drag:
“What blazed ahead of you? A faked road block?
The red lamp swung, the sudden brakes and stalling
Engine, voices, heads hooded and the cold-nosed gun?”
—Seamus Heaney (b. 1939)
“Executives are like joggers. If you stop a jogger, he goes on running on the spot. If you drag an executive away from his business, he goes on running on the spot, pawing the ground, talking business. He never stops hurtling onwards, making decisions and executing them.”
—Jean Baudrillard (b. 1929)