Originally Posted by
79pmooney
bark_eater There is an issue that might be there and will seriously affect mounting either a Heuret RD or any other. The hanger type. Older Heuret RDs used a different position for the "B" screw and the hangers reflected it. The hanger stop is something like 45 degrees forward of the common ones. (counter-clockwise looking at the bike from the right side). This was the French standard in the early days of derailleurs and stayed on at least into the early '70s. Older Simplex RDs and dropourts used the same standard. (My '73 Raleigh Competition came with Heuret dropouts and hanger.) The Japanese copied the Campagnolo Campagnolo standard and that became the ISO standard. Heuret and Simplex may well have also moved to the new ISO when it was adopted. I do not know,
Older Simplex dropouts used an unthreaded hanger, and needed to be tapped in order to mount a non-Simplex derailleur. Later Simplex dropouts were threaded, even though Simplex deralleurs didn't use the threads.
Huret dropouts were threaded, but the pivot stop was not compatible with non-Huret deralleurs.
Huret made two different adapter washers to accommodate either Huret or Campagnolo-type dropouts:
