Lucien Juy
Lucien Charles Hippolyte Juy | |
|---|---|
| Born | Dijon, Côte d'Or, France |
| Occupation(s) | Entrepreneur, inventor |
| Known for | Invention of the first derailleur with a foldable parallelogram mechanism; Simplex derailleur models with jockey wheel |
Lucien Charles Hippolyte Juy was a notable French entrepreneur recognized for his groundbreaking work in derailleur gear technology. He invented the initial derailleur incorporating a foldable parallelogram mechanism, featuring a hinged structure that enabled the chain to shift across multiple sprockets. His Simplex derailleur models were the first to utilize a jockey wheel, ensuring consistent chain tension despite changes in sprocket size.
History
Operating a bicycle repair and sales shop in Dijon, Côte d'Or, France, Juy introduced the inaugural Simplex derailleur in 1928. According to bicycle historian Hilary Stone, this design employed a spring-loaded arm coupled with a single pulley to maintain chain tension—a concept that laid the groundwork for contemporary indexed shifting systems. Juy persuaded the Alcyon racing squad to experiment with his derailleur at the 1928 Paris–Roubaix race, though the riders were hesitant to adopt this novel technology.
By 1933, Juy reported an annual output of 40,000 derailleurs, with his innovations playing a role in securing four French national championship titles that year. His 1936 Champion du Monde five-speed model was pioneering in its use of a narrower 3/32-inch chain. Significantly, Antonin Magne clinched the world championship that year utilizing this gear system.
In 1962, Juy advanced derailleur design by producing front and rear models constructed entirely from nylon frames made of polyoxymethylene (known commercially as Du Pont's "Delrin"). Although this represented a radical departure from traditional metal parts, the approach ultimately did not succeed. Manufacturing of Simplex derailleurs ended during the 1990s. A street in Dijon commemorates Juy's contributions.
From 1950 through 1980, Juy secured 26 patents in the United States predominantly related to bicycle componentry.