The Derailleur: A Century of Getting in Gear

/ 01

The Problem of Gears (pre-1900)

Early Safety Bicycles had a single gear — one chainring, one cog. To change gearing you literally flipped the rear wheel on a flip-flop hub, or owned a bike with an internally-geared hub. Sturmey-Archer's three-speed (1902) worked, but it was heavy and limited in range.

Road racing needed something lighter, with more ratios, and ideally with the rider still able to change gear while moving. The solution was a mechanism that pushed the chain across a cluster of rear sprockets — the derailleur.

/ 02

The First Derailleurs (1905–1930s)

Credit for the first recognizable derailleur usually goes to French touring advocate Paul de Vivie, known as Velocio, who patented a two-speed design in 1905. A 1896 patent by Jean Loubeyre for the Polyceler also exists, but was never commercialized.

By the 1920s derailleurs were a fixture on French randonneur and cyclo-touring bikes. Oscar Egg's Super Champion and the Nivex were highly regarded by riders who cared more about gear range than aesthetics. These mechanisms were operated by reaching back and turning a lever by hand.

/ 03

Tullio Campagnolo (1927–1951)

Tullio Campagnolo, racing in the 1920s, supposedly froze his fingers on the Croce d'Aune pass trying to flip his rear wheel. The result was his 1927 quick-release skewer — still in use, almost unchanged, a century later.

In 1933 he introduced the Cambio Corsa, a parallelogram mechanism operated by reaching back and turning a wing-nut lever. The 1951 Gran Sport was the first true modern derailleur: a cable-actuated parallelogram an amateur could afford. The basic geometry — two pivots, two jockey wheels, a cable spring — is still in use today.

/ 04

Indexed and Integrated Shifting (1984–1990)

Through the 1970s, friction shifting meant you felt the chain into gear. In 1984 Shimano released SIS — Shimano Indexed Shifting — where each click on the shifter lever corresponded to a precise derailleur position. Indexing demanded closer tolerances on cog spacing, chain, and derailleur geometry; it also transformed the riding experience.

Shimano followed up in 1990 with STI (Shimano Total Integration) — brake/shift levers that let you change gear without taking your hands off the hoods. Campagnolo's Ergopower followed in 1992, and SRAM's DoubleTap in 2006.

/ 05

The Electronic Era (2009–)

Electronic shifting eliminates the cable, the housing, the friction, the drift. Campagnolo's Record EPS shipped in 2009; Shimano's Dura-Ace Di2 followed the same year, with SRAM's wireless eTap arriving in 2015.

Today's top-tier groupsets shift under load, auto-trim the front derailleur, and sync shift across chainrings. The mechanical parallelogram Campagnolo patented in 1951 is still in there — just operated by a servomotor instead of a tensioned wire.

/ 06

Derailleur Timeline