Shifter (bicycle part)

Shift lever is a collective term for switches of different designs for actuating a gear shift on bicycles or mopeds.

History

Bike circuits were invented in the 1930s. They were operated directly. The so-called front derailleur had a metal rod with a lever at the other end. This was operated by hand or foot. The shift lever was just a metal rod, with which one has the chain cage directly rotated back and forth basically.

It was not until the early 1960s onwards that to place the lever closer to the hands of the rider. The operation took place - until today - via a Bowden cable. By means of a lever, pull the Bowden cable which moves the derailleur or the derailleur. If one loosens the Bowden cable, a spring moves the cage in the opposite direction.

Friction or index shift lever

When friction levers ensures a certain sluggishness (friction) that the spring in the rear derailleur or derailleur not adjusted the circuit independently. The driver must not only spend when pulling on Bowden a certain force, but also, if he wants to loosen the Bowden cable.

Index lever lock in a plurality of positions, which facilitates the choice of the path. When the levers for the rear derailleur corresponds with correct settings each notch on one sprocket. This mechanism of engagement is called indexing. When the levers for the front derailleur there are more catch steps as chainrings, because by the skew of the chain intermediates are required (depending on the ring gear ). With the exception of Rohloff 500/14 is carried out at all of today's circuits in the shift lever. This is easier to implement and cheaper. The Rohloff indicated in the hub, around 1990, there was a derailleur Shimano positron, which is also indexed to the rear derailleur. This technology with Bowden cable which spilled over pressure, could not prevail.

The distance traveled per turn of the Bowden cable differs depending on manufacturer and model. It is therefore necessary to look for when selecting an indexed shift lever that it matches the derailleur or the derailleur.

Hubs have always been indexed systems, as the mechanics may be damaged easily by inaccurate lever position. In derailleurs until the mid- 1980s friction shift lever were in use, had to be in which the correct position of the shift estimated or controlled by a look at the chain.

Rotary handle

This is the oldest design of the shift lever, it was also on motorized bicycles ( mopeds ) are common. For decades it fell into oblivion, 1990, were obtained from Campagnolo in design " Bullet" for ATB (All Terrain Bike) rediscovered. While the Bullet handles are rotated in total, another type is characterized by a split grip. A Renaissance experience these handles currently in mountain bikes and touring bikes. Description The "Grip Shift" the company SRAM has become a synonym for turning handles.

Other companies ( eg Rohloff ) also use twist shifters, where only a part of the steering handle is turned.

Knobs are very easy to build and produce and are therefore in the low price sector encountered almost exclusively. They may even consist mostly of molded plastics, and four or in the simplest case only two parts. A visible gear indicator can be reached by simply printing the transfer coefficients on the rotating handle.

There are also high-quality designs that enable long-term precise shifting.

Twist shifter is available as a friction switch and indexed versions. In many of today's circuits indexing in the handle, which makes this according to complicated and expensive to manufacture takes place. In this version must also be made more accurately the Bowden cables, since they are responsible for the shift with precision. The only exception is currently the shifting Rohloff 500/14, in which the indexing in the circuit happens.

Knobs are much less prone to failure than other shift lever designs because of them not above are parts that get stuck, can bend or break. The partially existing mechanics is built well encapsulated in the interior of the handle and keep clean. Switching operations are intuitive to implement, as there is only one operating element per cycle and you can all the gears in a row.

Frame shift lever

This design was common on road bikes, but today it is no longer common. One or two levers are mounted in the upper third of the tube on Anlötsockeln or a clamp. The use of these grips requires routine because you can easily fall into the spokes with your fingers. In addition, the switching operation is comparatively long, because you only take to operate a hand from the handlebar and must reach down. There are designs as a friction switch and indexed systems ( since about 1985). These switches have so racers operate an over conventional systems currently lighter weight, isolated even today the derailleur over such a shift lever. One advantage is that the Bowden cables can be laid without shell and thus run very low friction.

Shift lever on the stem

In the 1980s until the mid- 1990s, this shift lever were used primarily in indexed derailleurs. They resemble the frame shift levers and are no longer available new today.

Shifter on the handlebar

Together with the knobs which is the most widely used design. It is operated by small levers or buttons, which are operated with the thumb or index finger. Shift lever of this design principle are indicated. Often they are combined with brake levers, which are operated by the middle finger and the ring. So it is possible, within certain limits, at the same time to brake and turn. Shimano calls this form Rapidfire.

Operating lever for the triathlon aerobar

Triathlon bikes have an essay on the handlebar for storing the forearms so that the driver can drive for an extended period in strongly bent position. There are special lever for the aerobar. Similarly, attached by clip frame switch can be used.

Bar end shifters

Since the 1960s Cyclocross wheels usual. Later spread also to travel and racing bikes - there mainly to triathlon handlebars essays. Since the 1980s, they are also available as an index lever (eg SunTour XC Pro, etc.). The indexing is in some levers ( Shimano ) switched off.

Brake control handle

This design has replaced the shift lever frame and made ​​it on the road bike and similar bikes. Since the 2003 model year, this switching ability of Shimano is also available for mountain bikes. The circuit is actuated by lateral tilting of the brakes or by an additional lever directly behind the brake lever. Brake control handle are relatively expensive and have a complex inner life. Therefore, repairs are costly, sometimes even impossible. The switching is very comfortable, but also less accurate than with simple levers. Due to the longer cables and covers modifications to the geometry of parallelograms the derailleurs are necessary. This has the consequence that older derailleurs with brake switch handles work only sometimes or not at all.