Hello everyone (first post - yeay),

I have seen many forums posts that the simplex dropout could be modified to fit the standart 10mm screws. So I went to the bike shop today to ask them to change it from 9mm to a threaded 10mm and not only could they not do it also they said the metal is too thin and there is a risk I could only do two turns, which could be to few.

Now I want to ask the forum - is this such a bad idea? I really like the Mavic 851 as it is a part from my uncle from the late 80s. Shall I just buy an "ugly" (IMO) simplex derailleur or change the frame?

Thanks alot for your comments
micki

I did it myself to 72 PX10E... just ran a tapered tap in, cut a notch with a file and mounted Campy NR derailleur. I don't recall it being that thin, but I think your problem is the bolt itself that the threads don't come all the way back. Before modifying possibly look for a different bolt for that DR. Your frame is earlier than 1970s?

I've threaded Huret dropouts with no problem, but let's get somebody that can tell us definitively.
[MENTION=61614]verktyg[/MENTION] off the top of my head is one of our French bike experts.

edit: looks like [MENTION=364968]trailangel[/MENTION] has experience in this matter as well.

It looks like a different Simplex dropout than the one on my Peugeot

Could probably use a dropout saver. Dropout Saver

Or consider putting a something like a 2.5mm thick washer on the bolt before mounting.

Thanks for the hints. Never heard of drop out savers before.
Looking at the bottom number of the frame it is 7 digit, so I guess it is a 1970 frame.

I guess I need to sleep over it. In the "worst case" I keep the mavic parts as an excuse to build another bike in the next year:/...

Thanks

I would either use the dropout saver, or thread the hanger and put a thin bolt on the back. The saver would be less of a pain.

How thick is the hanger?

The hanger is nearly 6mm. It's not that far of form the length of the threaded area of the bolt. There is alittle area without a thread on the bolt.

The dropout saver is a nice idea, but this will additionally make the whole bigger - because I still need to sand to get the 7oclock stopper on the side.

Pinching the hanger between the Saver's wrench flats and the derailleur bolt should should make the hanger stronger, even with a larger hole.

Do you have enough metal for the 7 o'clock stop? I know the Mavic stop is closer than a B screw.

Does this frame ride well? The Mavic stuff is old school, but it works really well and deserves a good frame.

It will be thin, but not too thin. Mine was done 30 years ago. It was a very common modification.


Don't bother with the dropout saver. It's not necessary.

Beautiful drivetrain. I don't recognize the rear mech- what is it?

It's a Sachs/Huret. I can't recall the model. It's not high end. The cage is steel. The bike now wears a first generation Campagnolo Rally, even though the Sachs/Huret shifts better. I wanted to keep it all Campy.