The Supjam Sport is a beautiful example of Supjam's policy of combining random features of the French derailleurs of the time. The main body is pure early-1950s Huret Competition. The pulley cage is an even purer copy of that of a 1946 Simplex Champion du Monde 46, right down to the p-pivot being concentric with the guide pulley. As with many Supjam features, this is odd, because it probably makes the gear change significantly worse than if they had done the easy thing and simply copied the Huret pulley cage.

This example of a Sport has steel parts with a slightly dull plated finish. It also has a golden, aluminium, outer pulley cage plate, a blend of affordable function and aspirational glamour that would have made Eva Perón proud.

One final oddity is that the hole for the dropout bolt is small (Huret used a large diameter hole) and is threaded.

This, comprehensively wrecked, example has its tension pulley bolt labelled '3 Velocidades' - so this is a 3 speed.

• Derailleur brands: Supjam
• Themes: A riot of colour
• Country: Argentina
• Date of introduction: 1953?
• Date of this example: unknown
• Model no.: unknown
• Weight: 241g without the dropout nut and bolt and cable clamp nut and bolt
• Maximum cog: 24 teeth (guess)
• Total capacity: 24 teeth (guess)
• Pulley centre to centre: 51mm - it's a little hard to tell as it is in such bad condition!
• Index compatibility: friction
• Chain width: 1/8"?
• Logic: low normal
• B pivot: none
• P pivot: sprung
• Materials: steel with an aluminium outer pulley cage plate