This article is about the gearing system of a bicycle. For the railroad derailer, see Derail. For the act of derailment itself, see Derailment.
Variable-ratio transmission system commonly used on bicycles
This article's lead section may be too short to adequately summarize the key points. Please consider expanding the lead to provide an accessible overview of all important aspects of the article.(April 2021)
Shimano 600 front derailleur (1980)
A derailleur (French pronunciation:[deʁajœʁ]) is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another.[1]
Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a shifter mounted on the down tube, handlebar stem, or handlebar. When a rider operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets.
^Oxford English Dictionary (2nd ed.). 1989. derailleur, n. A bicycle gear in which the ratio is changed by switching the line of the chain (while pedalling) so that it jumps to a different sprocket on the rear wheel. Also derailleur gear.
A derailleur (French pronunciation: [deʁajœʁ]) is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes...
cog sizes. They were standard on most older derailleur bicycles from before the 1990s. An older derailleur-equipped bicycle with horizontal dropouts can...
lubricants are sealed within the shell of the hub gear, in contrast with derailleur gears where the gears and mechanism are exposed to the elements. Changing...
the bicycle. On single-speed bicycles and multi-speed bicycles using derailleur gears, the gear ratio depends on the ratio of the number of teeth on the...
rate Derailleur: an assembly of levers, usually cable-actuated, that moves the chain between sprockets on a cassette or chainring assembly Derailleur cage:...
producing its version of pull-chain, rod-guided, touring derailleurs, similar to those of French derailleur companies such as Huret and Simplex. In 1964, Suntour...
Checker and the Derailleurs is a 1988 novel by American novelist Lionel Shriver. The novel, Shriver's second, follows the life of rock drummer Checker...
Hippolyte Juy was a French industrialist who made derailleur gears. He is credited with making the first derailleur with a collapsible parallelogram. A hinged...
consisted of a triple-, double- or single chainring crankset, front and rear derailleurs, handlebar-mounted "finger" shifters, cantilever brakes, and large-flange...
An autobike or automatically geared bicycle is a bicycle with a derailleur or internally geared hub (transmission) that shifts gears without intervention...
the 1930s. After a crash-course in new frame-building techniques and derailleur technology, Schwinn introduced an updated Paramount with Reynolds 531...
bike rear derailleur, dubbed “ESP”, that featured a 1:1 cable actuation ratio that was more tolerant of cable contamination. The new derailleur was compatible...
reverse direction. Derailleur systems were first developed in the late 19th century, but the modern cable-operated parallelogram derailleur was invented in...
construction or frame type (upright, folding, etc.); by gearing (single speed, derailleur gears, etc.); by sport (mountain biking, BMX, triathlon, etc.); by means...
while racing, such as the quick release mechanism for bicycle wheels, derailleurs, and the rod gear for gear changing. Campagnolo has been awarded more...
The chain is also more flexible sideways, which is needed for modern derailleur gearing, because the chainline is not always straight in all gear selections...
type of master link comes closest to being re-usable. For bicycles with derailleur gears, a special kind of master link has been developed to fit the narrow...
consist of a front bottom bracket with one or more chainrings, and a rear derailleur. Depending on the configuration of the velomobile there may be any number...
introduced their own versions of the derailleur. SunTour notably introduced the slant parallelogram rear derailleur design in 1964, which is tilted to keep...
efficient dérailleur system, by which the chain is moved between different cogs called chainrings and sprockets to select a ratio. A dérailleur system normally...
mechanism. The other end is often clamped (as can be seen in the rear derailleur picture) to the part of the brake or shifter that needs to be moved, or...
gear shift levers, brakes, brake levers, cables, and front and rear dérailleurs. Shimano Total Integration (STI) is Shimano's integrated shifter and...
component manufacturer Shimano to a sprocket design in their bicycle derailleur tooth cassette systems. It varies gear tooth profiles, and/or pins along...
frame near the crank, and it may be used in addition to or instead of derailleur gears or a hub gear. Cited advantages include improved shifting performance...
drivetrain components of the bike should also be considered. A middle grade dérailleur is sufficient for a beginner, although many utility bikes are equipped...
innovate introducing the 4 Star derailleur gear in 1949 along with an associated 4-speed 'unit' or cassette hub. The derailleur design was altered from 1950...
Global Information
