This is the earliest derailleur patent that I have been able to find that is attributed to Nicholás Arregui Gallastegui, the founder of Zeus. The clear, precise, technical drawings show a cleanly executed copy of a late 1930s Simplex Champion du Monde.

It fits with my overall picture of Zeus as a company that was big on no-fuss technical quality but a bit light on game-changing originality.

• Publisher: Oficina Española de Patentes y Marcas
• Inventor: Nicholás Arregui Gallastegui
• Country: Spain
• Date: Spanish application filed June 1941
• Derailleur brands: Zeus possibly intended to be marketed as Simplex
• Derailleurs: unknown