Chris, all Simplex derailleur from the 60's on should fit those DOs including Prestige, Criterium, and the nearly infinite number of different versions of the alloy derailleurs collectively referred to as the Super LJ. The Simplex incorporates a spring load upper pivot with tabs that fit on either side of the unnotched DO. A nut slides into the DO from the inside and the pivot bolt threads into the nut rather than directly into the DO. Many Huret derailleurs also had a similar arrangement to fit Simplex DOs.
Regards,
Jerry Moos
Chris Beyer wrote:
> Greetings:
>
> I know this was discussed not to long ago, but I was asleep during the
> class session.
>
> I have recently acquired a French frameset which has Simplex dropouts,
> and an unthreaded derailleur hanger with no stops. What do I use for a
> rear derailleur? I think the frameset is most likely late '70s.
> Unfortunately, I have no hands-on familiarity with Simplex derailleurs
> any more recent than the TDF (exept for the evil black plastic thing).
>
> I seem to recall having seen reference to some sort of adapter which
> Huret offered for the Dupar/Challenger, but I've never seen or touched
> one.
>
> If you know what I need, and have one to sell, please respond off-list.
>
> Thanks,
>
> Chris Beyer
> Balmy (60s today) Bloomfield, NJ