Originally Posted by
non-fixie
Thanks, Chas, for your elaborate reply. Much appreciated!
I hadn't even got to the point where the mangled pivot bolt would have become a problem. Thanks for pointing that out. Saves me a lot of time and frustration.
I have a other - newer and better - Simplex derailleurs, but this particular one would have looked really nice on my 1968 Jacques Anquetil. Oh well.
What I'm still not getting, though, is the five o'clock position of the tab. It is purely the result of the locations of both the spring end and the groove in the stop plate (part 2580). My initial reaction was the same as yours (Huret? NON!), but I still haven't any other logical explanation.
I looked for a replacement stop plate in my parts bin last night, but the ones I have are all like the one below you posted. They require a "ledge" which the 537 doesn't have.
I think I'll mount a newer SX-somethingorother for now, but the 537 looks awfully pretty with its blue hue, and I'll keep looking for a new pivot bolt and Simplex-compatible stop plate.
The stop plate that you have IS the correct part. Those Simplex derailleur stop plates look weird until you mount them onto the dropout. There is a small amount of preload in the upper pivot when the tab is placed over the leading edge of the dropout that will correctly position the derailleur.
Newer all metal SLJ derailleur showing where the stop tab should sit. Simplex used this method from the mid 60's until the end. It allowed their derailleurs to be mounted on most dropouts including proprietary Huret dropouts (with a little modification).
You probably caught this but the upper pivot needs to be pushed further in so that the spring engages the slot in the stop plate. What a Rube Goldberg design!
verktyg
