This is Charles Jeanmot’s second JIC derailleur patent and, regressing from his 1932 patent, it shows a design of consummate impracticality. It is rod operated, impossibly flexible and terrifyingly fragile. Time to go back to that drawing board.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Charles Jules Jeanmot
• Country: France
• Date: Luxembourg application June 1934, French application October 1934
• Derailleur brands: JIC
• Derailleurs: unknown JIC model