Billy,
The Huret Challenger and Success rear derailleurs had 2 threaded holes where the lower pivot screw attached the cage to the body. They were about 10mm apart and marked 24T and 28T.
Their function was to raise or lower the pulley cage. With the 28T position it gave enough clearance so that the upper pulley could move under a 28T sprocket. In the 24t position it provided better shifting because the pulley location was optimized for a smaller freewheel.
The spring tension was also easily adjustable for each position on many of these derailleurs.
I suspect that Huret may have made a change in the cage position for the 28T models.
The best shifting occurs when the top chain pulley is at an optimized distance from the sprockets. That was the advantage SunTour had with their slant parallelogram design and why most RDs eventually shifted to that style geometry (pun intended).
Chas. Colerich Oakland, CA USA
billydavid13@comcast.net wrote:
> Hi Richard. I pulled out Sutherland's, 2nd ed. and here's what they offer: Jubilee 2200 [short cage]; w/ 32-52 chainwheels: 13-24. w/36-52 chainwheels: 13-26. w/40-52 chainwheels: 13-28. It's possible the Huret catalog just got the chainwheel sizes wrong. But that begs the question as to why they have 2 ref. nos. Which, in turn, begs the question why there are no separate illustrations for the 2 ref. nos. I trust Sutherland's and Jerry Moos' observation that the short cage will handle a 28 if it doesn't have too much chain to wrap. Billy Ketchum; Chicago, IL; USA.
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