The Capo Exakt was a well made copy of a 1950s Simplex Tour de France, sharing the Simplex's basic geometry and rather sub-optimal pulley cage arrangement. However, the detailed design of both pivots was considerably better than that used by Simplex and the mechanical finish and tolerances were impressive throughout.

I think that this is an early example, with a flat main plate, round pulley wheels, conspicuously perfunctory branding and some kind of non-chrome plating (Zinc? Nickel?). All this points to it dating from a period of post-Second World War austerity and materials shortages. The reversed slot in the gear hanger plate may indicate that this derailleur was designed to be used in combination with a hub gear.

• Derailleur brands: Capo
• Country: Austria
• Date of introduction: 1952?
• Date of this example: unknown
• Model no.: unknown
• Weight: 318g including hanger plate, but excluding hanger bolt and cable clamp assembly
• Maximum cog: 28 teeth?
• Total capacity: 15 teeth?
• Pulley centre to centre: 46mm
• Index compatibility: 4 speed?
• Chain width: 1/8”?
• Logic: low normal
• B pivot: sprung
• P pivot: sprung
• Materials: steel, with aluminium chain tension adjuster ring