It's easy to forget that Lucien Juy patented his Simplex dropout 18 months before Tullio Campagnolo got around to patenting his (see French Patent # 1,036,415). It's also easy to forget that for some years the Simplex version was more common and arguably more desirable.

• Publisher: L’Institut national de la propriété industrielle
• Inventor: Lucien-Charles-Hippolyte Juy
• Country: France
• Date: Priority date June 1949
• Derailleur brands: Simplex
• Derailleurs: none