Derailleurs

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. more...

Home
Airsoft
Archery
Backyard Games
Baseball & Softball
Basketball
Bowling
Camping & Hiking
Cheerleading
Climbing & Caving
Cricket
Curling
Cycling
Accessories
Bicycle Parts
BMX Bike Parts
Brakes
Cranksets & Bottom Brackets
Forks
Handlebar Pads, Pad Sets
Handlebars & Grips
Headsets, Stems
Other
Pedals
Pegs
Rims & Hubs
Seats & Seat Posts
Sprockets, Chain Rings
Tubes & Tires
Wheelsets
BMX-Old School Bike Parts
Mountain Bike Parts
Brakes
Cassettes & Freewheels
Cranksets & Bottom Brackets
Derailleurs
Forks
Handlebars & Grips
Other
Pedals
Rims & Hubs
Seats & Seat Posts
Shifters
Shocks
Stems
Tubes & Tires
Wheelsets
Parts for Other Bike Types
Road Bike Parts
Brakes
Cassettes & Freewheels
Chain Rings
Cranksets & Bottom Brackets
Derailleurs
Forks
Handlebars
Other
Pedals
Rims & Hubs
Seats & Seat Posts
Shifters
Stems
Tubes & Tires
Wheelsets
Universal Bike Parts
Cables
Chains
Other
Seat Posts
Seats
Bicycles & Frames
Books & Video
Clothing, Shoes &...
Other
Vintage
Disc Golf
Equestrian
Fencing
Field Hockey
Fishing
Football
Geocaching
Go-Karts (Recreational)
Golf
Gymnastics
Hang Gliding & Paragliding
Hunting
Ice & Roller Hockey
Inline & Roller Skating
Lacrosse
Other
Paintball
Paragliding
Rugby
Scooters
Skateboarding
Sky Diving
Soccer
Track & Field
Triathlon
Volleyball
Wrestling

Although widely referred to as \"gears\", bicycle \"gears\" should properly be referred to as sprockets since they drive or are driven by a chain, and are not driven by one another.

Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a shift lever mounted on the down tube, handlebar stem, or handlebar. When a rider operates the lever while pedaling, the change in cable tension moves the chain-guide from side to side, \"derailing\" the chain onto different sprockets.

History

Various derailleur systems were designed and built in the late 1800s. The French bicycle tourist, writer and cycling promoter Paul de Vivie (1853-1930), who wrote under the name Velocio, invented a two speed derailleur in 1905 which he used on forays into the Alps. Some early designs used rods to move the chain onto various gears. 1928 saw the introduction of the \"Super Champion Gear\" (or Osgear, from the company founded by champion cyclist Oscar Egg), and the Vittoria Margherita; both employed chainstay mounted 'paddles' and single lever chain tensioners mounted near or on the downtube. However, these systems, along with the rod operated Campagnolo Cambio Corsa were eventually superseded by parallelogram derailleurs. Derailleurs did not become common road racing equipment until 1938 when Simplex introduced a cable-shifted derailleur. In the early 1950s the cable-operated, parallelogram variety used on today's bicycles was introduced by Tullio Campagnolo, who also invented the quick release skewer for attaching the wheels. With Campagnolo's introduction of the parallelogram derailleur, Campagnolo became the standard for high quality derailleurs for several decades with its Gran Sport, Record, Super Record gears. Before the 1990s many other manufacturers also made derailleurs, including Simplex, Huret, Galli, Mavic, Gipiemme, Zeus, Suntour, and Shimano. However with introduction of indexed gears which required all parts of the drivetrain to be compatible, and the increasing use of groupsets made by one company, today Campagnolo and Shimano are the two main manufacturers of derailleur gears, with Campagnolo only making road cycling derailleurs and Shimano for both road and mountain bikes. American manufacturer SRAM specializes in derailleurs for mountain bikes, but in 2006 SRAM introduced a drivetrain system for road bicycles.

In 1964, Suntour invented the slant-parallelogram rear derailleur, which let the jockey wheels maintain a more constant distance from the different sized sprockets, resulting in easier shifting. Once the patents expired, other manufacturers adopted this design, at least for their better models.

Read more at Wikipedia.org