In 1932 Claudius Jacquemard applied for this patent for what appears to be a lightweight racing derailleur designed to work with a close ratio 3 speed freewheel. It is striking that, during the 1930s, racing was seen as requiring very simple, not to say, crude, designs, with all complexity and sophistication reserved for touring models.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Claudius Jacquemard
• Country: France
• Date: French application June 1932
• Derailleur brands: Idéal
• Derailleurs: Idéal