FACTOID # 46: Japan has 53 working nuclear reactors and is planning to build another 12.
 
 Home   Encyclopedia   Statistics   Countries A-Z   Flags   Maps   Education   Forum   FAQ   About 
 
WHAT'S NEW
RECENT ARTICLES
More Recent Articles »
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Shifter (bicycle part)
A twist-style seven-speed indexed shifter made by SRAM
A twist-style seven-speed indexed shifter made by SRAM
A pair of down tube shifters.
A pair of down tube shifters.
A right (rear) Shimano 7-speed below-the-bar shifter with integrated brake lever.
A right (rear) Shimano 7-speed below-the-bar shifter with integrated brake lever.
A pair of stem mounted shifters.
A pair of stem mounted shifters.
A 3-speed trigger shifter on a Triumph.
A 3-speed trigger shifter on a Triumph.
A bar-end shifter.
A bar-end shifter.
Shimano 9-speed STI levers
Shimano 9-speed STI levers

A bicycle shifter or gear control or gear levers is a component used to control the gearing mechanisms and select the desired gear ratio. Typically, they operate either a derailleur mechanism or an internal hub gear mechanism. In either case, the control is operated by moving a cable that connects the shifter to the gear mechanism. Shifters are mounted on the down tube of the frame, on the handlebars, or at the ends of triathlon bars. Major manufacturers of shifters include Shimano, Campagnolo, and SRAM. Image File history File links Schaltgriff-sram-7. ... Image File history File links Schaltgriff-sram-7. ... SRAM Corporation is a privately held bicycle component manufacturer based in Chicago, Illinois, founded in 1987 [1]. The correct pronunciation of SRAM is sram, as indicated on their website FAQ. SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, where Ray is the middle name... Steel frame and carbon fiber fork of 2000 LeMond Zurich racing bicycle A bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. ... The stem is the component on a bicycle that connects the handlebars to the steer tube of a bicycle. ... Head badge of a Triumph bicycle. ... Image File history File linksMetadata Download high resolution version (1194x1024, 297 KB) Summary Shimano 105 5500 series brake lever/shifter set Photo taken by thewalrus July 2005. ... Image File history File linksMetadata Download high resolution version (1194x1024, 297 KB) Summary Shimano 105 5500 series brake lever/shifter set Photo taken by thewalrus July 2005. ... For other uses, see Bicycle (disambiguation). ... Derailleur gears are a variable ratio transmission system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ... Hub gears or internal-gear hubs are a type of gear system used on bicycles. ... Invented by Frank Bowden, a bowden cable is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable (most commonly of steel or stainless steel) relative to a hollow outer cable housing. ... Drop handlebars on a racing bicycle allow the rider a variety of positions for aerodynamics and comfort. ... Triathlon bars is a catch-all term referring to various styles of aerodynamic handlebars for racing bicycles. ... Shimano, Inc. ... Campagnolo Ergopower lever Campagnolo is an Italian manufacturer of bicycle components with headquarters in Vicenza, Italy, historically regarded as one of most prestigious brand names in cycling. ... SRAM Corporation is a privately held bicycle component manufacturer based in Chicago, Illinois, founded in 1987 [1]. The correct pronunciation of SRAM is sram, as indicated on their website FAQ. SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, where Ray is the middle name...


The controls are mounted so that the right shifter controls the rear derailleur and the left shifter controls the front derailleur. For hub gears, the control is also mounted on the right.


Over the years, many different kinds of shifters have been used. The trend in development has been to reduce the need for the rider to direct attention away from riding. Friction shifters gave way to index shifters, which do not require fine-tuning during a gear change. In the 1990s, shifters were placed closer to the hand positions on the handlebars, up to the point of being integrated with the brake lever control.

Contents

Friction shifting

Originally, gear control levers consisted of a simple lever. Changing gears required pushing or pulling the lever so that the derailleur would move the chain to a different sprocket on the rear hub. The cyclist would need to adjust the lever to center the chain on the sprocket. Roller chain and sprocket A bicycle chain is a chain that transfers power from the pedals to the drive-wheel of a bicycle thus propelling it. ... This article does not cite its references or sources. ...


This system started out with 2 or 3 sprockets, and by the 1970s had developed to 5 and 6 sprockets. Many inexperienced cyclists, especially those who started in the US 1970s bike boom, found it difficult to change gear accurately. Typical difficulties included gear changes that left the chain in between two sprockets, which causes noisy rattles, or undesired and unexpected gear changes. However, many experienced cyclists still prefer friction gears for its simplicity and long-term reliability, as well as the ability to mix and match components from different manufacturers without the compatibility issues of indexing systems. In addition, the introduction of ramped freewheel sprockets (such as Shimano's Hyperglide system) and derailleurs with floating jockey wheels has made accurate gear changes much easier than previously. The bike boom of the 1970s was a period in which bicycles and cycling became popular among adult Americans, after several decades in which bikes had been relegated to the status of toys. ... Shimano 7-speed cassette showing the Hyperglide teeth profiles In bicycle derailleur systems, a series of ramps, varying gear tooth profiles, and/or pins along the faces of freewheel or cassette sprockets, or between the chainrings in a crankset, to ease shifting between them. ...


Index shifting

Index shifting is a system where the control has discrete stops. Hub gears by design are indexed, so for derailleur systems, indexing was an innovation. Each stop corresponds to one position of the derailleur. This allows the cyclist to change gear without having to adjust each time, as in friction shifting.


The first successful indexed shifting system was the Shimano Index Shifting or SIS, introduced in 1984 on the 6-speed Dura-Ace racing groupset. This made it near impossible to misshift, but at the expense of having more difficult initial adjustment. Most modern bikes made today are equipped with index shifting. Prior to this Shimano had sold a system called Positron which placed the 'clicks' in the derailleur, however this system was only targeted at cheaper bicycles and gained a bad reputation. All modern indexed shifting places the clicks in the shifters. This article is about the year. ...


Index shifter styles include twist shifters, trigger shifters (such as Shimano's Rapidfire design), shifters integrated with brake levers, levers mounted on the downtube, and bar-end controls. A twist shifter is mounted in line with the handlebar grips. Shifting is controlled by rotating the grip of the shifter. Trigger shifters have separate levers that change gears to the next gear up or down. Early indexed shifters could be used in friction mode for backwards compatibility, but this feature is no longer common.


New mountain bicycles use either twist shifters or trigger shifters. Older mountain bicycles may have thumb shifters, either indexed or non-indexed. Shimano's Deore, LX, XT, and XTR mountain groupsets include combined brake/shift controls, called Dual-control. Moving the brake lever perpendicular to the direction to control the brakes operates the shift mechanism. A mountain bike in the forest Freeriding on a Hardtail freeride bicycle A full suspension Mountain Bike A rider during a Cross Country race A mountain bike, mountain bicycle or ATB (All Terrain Bicycle) is a bicycle designed for riding off-road, either on dirt trails or other unpaved environments...


Given that friction shifters were compatible with almost any derailleur, index shifting systems have been criticized for their non-interchangeability. For example, Shimano indexing components are often incompatible with SRAM or Campagnolo components, because the amount of cable pulled between each "click" is different in each system. In addition, newer components are often not backward compatible with older systems from the same manufacturer, so finding spares for older systems is often difficult, and stocking all of the possible combinations (shifters, derailleurs, chainrings, freewheels, and cassettes) is a challenge for the local bike shop. Some components can be mixed and matched between systems, but it can a bit of a kludge to do so. Component manufacturers have been accused of planned obsolescence for introducing more and more complicated shifting systems--and withdrawing support for older systems--to a riding public which generally doesn't need so many gears for basic transport, utility, or recreational cycling. Campagnolo Ergopower lever Campagnolo is an Italian manufacturer of bicycle components with headquarters in Vicenza, Italy, historically regarded as one of most prestigious brand names in cycling. ... In technology (especially computing), backward compatibility has several related but differing meanings: A system is backward compatible if it is compatible with earlier versions of itself, or sometimes other earlier systems, particularly systems it intends to supplant. ... Mountain bicycle with Derailleur gears 9x multiple sprockets of a Derailleur gear Derailleur gears are a gear system commonly used on bicycles, consisting of a chain, multiple sprockets and a mechanism to move the chain from one sprocket to another. ... A Shimano Deore right crankset, showing crank arm, spider, three chainrings and chainring guard The crankset, or chainset, is the component of a bicycle drivetrain that converts the reciprocating motion of the riders legs into rotational motion used to drive the chain, which in turn drives the rear wheel. ... An earlier design of a cogset. ... On a bicycle, the cassette or the freewheel is the set of rear sprockets that attaches to a hub on the rear wheel. ... This article does not cite any references or sources. ... Planned obsolescence (also built-in obsolescence[1] in the United Kingdom) is the process of a product becoming obsolete and/or non-functional after a certain period or amount of use in a way that is planned or designed by the manufacturer. ... Ugandan bicycle taxi or bodaboda Cargo-bicycle and Trike for rent Bremen. ... Recreational cycling is any cycling done for other than utilitary reasons. ...


One notable exception to the lack of compatibility in modern shifters is the fact that none of Campagnolo's front shifters are indexed, so they are compatible with all double or triple cranksets, even those of different manufacturers. Campagnolo rear shifters are also partially backwards compatible because a mechanic can upgrade them for use with a different number of rear sprockets by replacing a small part, the shift disc.


Brake/Shift Levers

Campagnolo Veloce 9-speed Ergopower lever
Campagnolo Veloce 9-speed Ergopower lever

Older road bike shifters may be down tube gear levers, mounted on the down tube of the frame. These have been available both non-indexed (friction) and indexed. If the levers are not mounted on the handlebar, the rider would have to move a hand from the handlebars to the gear lever to change gears. They could also maintain one hand on the handle bars and another on the gear lever, while accelerating. This made changing gears difficult while turning, going up hill, maneuvering in traffic, or during a race, as the rider would lose some stability from having only one hand on the handle bar, while adjusting the lever. Friction shifters had the added disadvantage of having to be trimmed every time the gear was changed, which might take a few moments. This led riders to usually stay in one gear, unless they were about to rapidly change their speed. Indexed shifters addressed the trimming issue, but the stability issue remained. Image File history File links Download high resolution version (517x1024, 88 KB) Summary from the German Wikipedia at de:Bild:Schaltbremsgriff. ... Image File history File links Download high resolution version (517x1024, 88 KB) Summary from the German Wikipedia at de:Bild:Schaltbremsgriff. ... Steel frame and carbon fiber fork of 2000 LeMond Zurich racing bicycle A bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. ...


With the introduction of systems like Shimano STI and Campagnolo Ergo, and the more recent SRAM system, the majority of these issues have been addressed. These systems combine an index shifter into each brake lever, and are were sometimes referred to as brake/shift levers (or brifters), for their ability to combine the brake and shift functions into a single unit for use with one hand. However, in recent times, the term brake has been dropped, and the levers are referred to simply as shifters. These shifters when combined with gear ramps and teeth shaping on the cassette address all of the issues with friction and index shifters. Shimano, Inc. ... Shimano Total Integration (STI) is a gearshift system designed by Shimano for racing bicycles. ... Campagnolo Ergopower lever Campagnolo is an Italian manufacturer of bicycle components with headquarters in Vicenza, Italy, historically regarded as one of most prestigious brand names in cycling. ... Ergo Shifting, also referred to as Ergopower or Ergolevers, is the dual-control shifting component design by Campagnolo for operation of the derailleurs on racing bicycles. ... SRAM Corporation is a privately held bicycle component manufacturer based in Chicago, Illinois, founded in 1987 [1]. The correct pronunciation of SRAM is sram, as indicated on their website FAQ. SRAM is an acronym comprising the names of its founders, Scott, Ray, and Sam, where Ray is the middle name...


Advantages

Shifters allow for rapid and precise shifting, without removing the hands from the handlebars. Because the shifter is a combination of gear lever and brake, the cyclist does not have to move their hands, and has both in easy reach. This addressed one of the principle disadvantages of previous designs. Shifter technology has been combined with gear ramps and tooth shaping on the cassette, to allow for the chain to transfer power while shifting. This allows the cyclist to shift more frequently to match the desired cadence. This makes shifters greatly superior to friction or index shifters in traffic or during a race. As the cyclist can accelerate more rapidly (thanks to rapid down shifting while pedaling), maintain a straighter line while accelerating (such as while riding along a curb in traffic, or during a race), and downshift while approaching an intersection or a hill. The ability to rapidly shift allows a cyclist to better maintain a good cadence and therefore cycle faster with less effort, as the gear is better suited.


For touring cyclists and recreational riders who use drop bars, shifters may make riding easier and more comfortable as they allow the rider to use more hand positions and also retain access to both the brakes and gear shifters at the same time.


In general, the additional weight, expense, and occasional maintenance of shifters on a road bicycle is far outweighed by the performance advantages in a racing context.


Disadvantages

Shifters are not without their disadvantages; the system is more complicated and subject to greater wear and tear than previous systems, especially friction shifters. Due to their greater number of parts shifters are more expensive and less reliable than index shifters. Index shifters and shifters rely on the cable tension to be maintained, but over time the derailleur cable will stretch, causing the system to slowly drift to the right of the gear. Periodic adjustments are required.


Bar-End Shift Levers

Because of the increased desire of the time trialist for an aerodynamic position on the bicycle, a time trial bike uses triathlon bars, a different bar arrangement to a road bicycle's drop handlebars. The controls are mounted at the end of the triathlon bars and are called bar-end levers or barcon, for bar control. Bar-end gear levers can also be used on the ends of drop handlebars. Triathlon bars is a catch-all term referring to various styles of aerodynamic handlebars for racing bicycles. ...


External links


  Results from FactBites:
 
Shifter (bicycle part) - Wikipedia, the free encyclopedia (913 words)
A bicycle shifter or gear control or gear levers is a component used to control the gearing mechanisms and select the desired gear ratio.
In either case, the control is operated by moving a cable that connects the shifter to the gear mechanism.
Shifters are mounted on the down tube of the frame, on the handlebars, or at the ends of triathlon bars.
Shifter - Wikipedia, the free encyclopedia (191 words)
Shifter (bicycle part), a bicycle part that selects which gear the chain rests on
Shifter (popular music), a word in pop music lyrics that can change what it refers to according to who is speaking
The gear shifter lever or gearstick of an automatic or manual transmission.
  More results at FactBites »


 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments
Please enter the 5-letter protection code

Want to know more?
Search encyclopedia, statistics and forums:

 


Lesson Plans | Student Area | Student FAQ | Reviews | Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms.