This fine object is an Argentinian copy of an early 1970s Huret Svelto. The designer at JC has 'improved' the adjustment screws by placing them in a position that is much more easily accessible for the weary mechanic. However, this new positioning makes them highly liable to be bent in the tiniest of minor accidents, or just by leaning your bike against a wall. I have seen a number of these derailleurs, and all the others, except for this one, had these screws bent like wet spaghetti. 'Al dente' they certainly weren't.
In general this derailleur is manufactured to the lowest possible tolerances, from steel with a tensile strength that would embarrass cheese. Even the plating is indecently poor - but consistency is a virtue.
Some other random points that I should make are:
- The writing on the underside of the outer parallelogram plate says 'INDUSTRIA ARGENTINA' - which might be the equivalent of 'made in Argentina'.
- The pulley wheels are unusual 9 toothed items with no dust covers at all.
- I have no real idea of the actual date of this product. My guess that it dates from sometime in the late 1970s is based solely on it being a copy of something from the early 1970s.
- Derailleur brands: JC
- Country: Argentina
- Date of introduction: 1978?
- Date of this example: unknown
- Model no.: unknown
- Weight: 223g
- Maximum cog: 24 teeth (based on an equivalent Huret Svelto)
- Total capacity: 28 teeth (based on an equivalent Huret Svelto)
- Pulley centre to centre: 42mm
- Index compatibility: friction
- Chain width: 3/32"
- Logic: top normal
- B pivot: unsprung
- P pivot: sprung
- Materials: steel or, if you prefer, cheese...