Fred
After I wrote to the List, I went down to my workshop and dug through one of my parts boxes and found no less than three Simplex plastic front derailleurs (all broken, of course). Turns out one of them had just the right bolt I needed for the chain guide to be secured to the shifting rod, and the nut and screw on the end of the (newer) chain guide was the same as the other nut and screw that is used as a limit adjuster on the rod.
So right now, it appears I have what I need. Thanks for the information on the thread dimensions, that explains why the hardware store did not have the right size metric screws. I wonder if hardware stores in France stock them.
David Lester
West Hartford, Connecticut, USA
http://www.wooljersey.com/
http://community.webshots.com/
http://velo-orange.blogspot.com/
----- Original Message ----- From: "Fred Rednor" <fred_rednor@yahoo.com> To: <classicrendezvous@bikelist.org> Sent: Friday, January 02, 2009 8:04 PM Subject: Re: [CR]Nuts and Bolts with French Threads
>
> > In trying to replace damaged or missing small nuts and bolts
> > on a Simplex rod-operated front derailleur, I find that the
> > threading is neither SAE or Metric. Is there a source for
> > this small hardware?
> David,
>
> This might be little comfort for your predicament, but the Simplex
fasteners do have metric theading. They just don't use the same thread
dimentions you're accustomed to finding on other bike parts. For example,
rather than using the typical 5mm x .8mm bolts, some French parts use .75mm per
thread for 5mm bolts. So those fasteners have finer threads than what's
expected. But Simplex took the opposite approach. That is, some of their
fasteners are 1.25mm/thread (or perhaps larger?) in cases where 1mm/thread is
typical.
>
> I think you can get some of pieces you need by finding plastic Simplex
front derailleurs and shift lever sets, and "borrowing" the fasteners
from them.
> Best regards,
> Fred Rednor - Arlington, Virginia (USA)