This is a tantalising derailleur. I have never seen it in any catalogues. So I have little idea about where it fits into Super Champion's slightly hazy history.

It is very aluminium. It is extremely light. It is rather well made. All of which makes you think it might be a sophisticated later Super Champion model.

But it is also very similar in operation to a 1935 Simplex Champion de France. It certainly lacks the hollow main tube that is a hallmark of all later Super Champion (and many, many, other) 1950s designs.

My best guess is that it is an early model and might date from 1938.

Finally, I should draw your attention to a number of striking details: both the bolt and the 'nut' at the b-pivot are aluminium, as is the locknut at the outside end of the sliding rod. Even the tiny cup that holds the end of the cable outer is aluminium (it is brass on most Super Champion models). There is a tiny, shaped, steel protective insert at the point where the toggle chain runs over the main arm. And, even though they are minute, the words 'Super Champion' are engraved on the main plate using Super Champion's signature Art Deco font. All very classy.

• Derailleur brands: Super Champion
• Themes: Ultra-lightweight - single pulley models
• Country: France
• Date of introduction: 1938?
• Date of this example: unknown
• Model no.: unknown
• Weight: 124g excluding tiny cable clamp bolt
• Maximum cog: 24 teeth?
• Total capacity: 10 teeth?
• Pulley centre to centre: none
• Index compatibility: friction
• Chain width: 3/32" and 1/8”?
• Logic: low normal
• B pivot: sprung
• P pivot: none
• Materials: largely aluminium, with a steel sliding rod