Bicycle gearing

The gears on a bicycle consists of a crank located between the drive and embossed rear shift transmission and the associated controls. This allows the speed to be adapted to the services performed by the cyclist performance.

Gear shifts are common in all modern bikes. A still existing exception is the so-called Eingangrad without gears, which is preferably constructed as a children's bike, but is also preferred by a few adult purists. Bicycles without gears are also sporadically encountered with cheap wheels. Input wheels are also used for artistic cycling and track bikes.

Technology

Types

  • Derailleur (since 1940), in which several sprockets on the rear wheel and often additionally several sprockets ( common term: gears ) are front exists and the bicycle chain by means of a switching station (rear) or front derailleur (front) can be placed on the different gears. Instead of the chain can be displaced transversely and the sprocket set: " Ultra-Shift ".
  • A special feature was the retro Direct built in the 1920s/30s, was elected in the by reversal of pedaling direction between two ratios. The switching is performed by two acting in opposite direction of rotation freewheels.
  • A special feature is the continuously variable NuVinci hub gear with a planetary gear system with friction instead of gears.

Controls

The circuit is operated usually by a suitable shift lever to the handlebar or front frame via Bowden cables. Besides the usual levers and knobs and two lever handles (trigger handles, each one lever for up and down ) been produced. Therefore, the word is used in connection with the change of gear ratios of machines and automobiles. By this is meant colloquially the possibility or the corresponding lever of the means for changing the gear ratio.

  • Electrical / electronic circuit: a regular circuit with actuation of the switching mechanism by an electric circuit instead of Bowden; in a single case, instead of the front derailleur a kind sprocket Soft
  • Electrically operated chain circuit with built- in front chainring "soft "
Single-speed bicycle Track bicycle Retrodirect
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