Simplex Dropout Screws
 

I bought some velo orange drop out screws for my 1977 px10le, but the hole is too large. And then i realized these holes aren't even threaded. I was putting the wheel all the way back previously (large tires). Should I tap these and get a larger screw? If so, what size? Or just use those peugeot dropout little spacer thingies? There must have been some on there a long time ago. I probably have some around here somewhere. Wondering why they made that hole in the first place.
https://cimg4.ibsrv.net/gimg/bikefor...61aa290b16.jpg

There are wee little plastic (it's Simplex) bits that fit in the holes and have a threaded cross-hole for the adjuster.

Except for you there aren't.

Don't drill or tap anything, that area is fragile enough as it is.

Trying to imaging how fiddly it would be to cut short lengths of steel or aluminum rod to fit those crosswise holes, and then drill & tap at 90 degrees. :twitchy:

the inserts are plastic of some sort. the screws are 3 x .5 x 30. the cap nuts are hexagonal.
the plastic inserts fit in the holes, the screws thread through them snugly, almost as if the screws were "self tapping" in them (even though the screws are not self tapping type). you can see the slight plastic deformation around the threads in the pics below.
there are no tension springs, all of the screw position retention relies on the tight fit of the screw in the plastic insert. if the threads in the plastic were to strip out, the inserts would be useless and there would be no screw adjustment.
while i haven't tried it, i don't think it should be too difficult to manufacture a similar insert.
i would not tap the dropout for a larger screw.

originals from my Super Competition.
https://live.staticflickr.com/65535/...9b69c22e_h.jpg

https://live.staticflickr.com/65535/...1bbdc47b_h.jpg

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...if it were me, I would use the little dropout spacer thingies. I have some in a parts drawer that I saved.

The hole is 5mm diameter. If you can source a 5mm plastic rod, you could drill a 2.5mm hole across the rod, tap 3 x 0.5mm thread in the hole, and slice it off to fit the hole.

oneclick is going to hook me up with some copies of the original he made. cheers!

My solution is to use an M3 screw and two M3 nylok nuts, and sandwich them in for those that can't find the standard part.

This situation would warrant at least an email to Wayne Bingham at Mel Pinto Imports. I never cease to be amazed at the old French small parts that he still has on hand….

cheers to oneclick for the fix!

https://cimg0.ibsrv.net/gimg/bikefor...7d1cc49787.jpg

Those little plastic pucks were most likely made from Delrin.....Simplex was literally addicted to this wonder plastic of that time.....It actually worked very well for retaining those adjustment screws.

I’m missing a single cap nut.
 

I suppose any tiny nut will work for the cap nut?

...if you look hard enough, you can probably find them for sale online int proper size and threading.
I just use two nuts of the correct size and threading, tightened against each other with small wrenches...double nutting.

Good to see that the problem has been solved.

My suggestion would have been to try torqueing in a #6 machine screw, seems like the .130" diameter would be close to what the hole is and it might be a just-right-tight fit and need no additional retention (or to run a #6 tap through about half(?) way, removing but a scant amount of material).

dukeofearl-

If you want originals, they are available: https://www.ebay.fr/itm/284348291440...Bk9SR5TRpo6bYg
https://i.ebayimg.com/images/g/7YAAA...xv/s-l1600.jpg

FWIW: this link seems to yield the same item on the US version of eBay as the link from @bertinjim (which is a link from eBay France).

https://www.ebay.com/itm/284348291440

I've had trouble in the past when trying to use eBay France links directly, but reformatting them as an eBay US link seems to work for me.