I just came across an old Peugeot frame. The seller claimes it is a PX-10. It does have the chromed stays, but no real ID plate on it. There is a number 77116 punched into the BB and it is painted over. i am just curious about the origin and model of the frame. Thanks.

Pictures if possible; I've seen faked chrome stays. I would do the following:
1) Check for "simplex" engraved on the rear dropout, over the derailleur.
2) Check for Reynolds 531 stickers on the frame and fork. These are often partial.
3) Look for the word "inoxyadable" on a sticker on the seat tube; these wear better than the 531 stickers.
4) Make sure it has an integral derailleur hanger
5) It should be either blue or white in color if the original paint is still on it. I've seen black, but in a very limited edition.
6) Read the following links:

https://www.classicrendezvous.com/Fra...ugeot_home.htm

https://www.classicrendezvous.com/Fra...10_history.htm

The serial number seems a bit off; sixties Peugeots have six digits; early to mid seventies seven.

If it is a PX frame, and it's your size, straight, true, no dents or dings, and the price is reasonable (the frames go for between 50-100$ bucks on ebay, sometimes more depending on vintage) I'd pick it up. They make great fixed gears. Check the headset and BB cups; if they're original, they're stronglights, which are built like tanks and pretty hard to destroy. If they're in good working condition, it saves you the difficulties of finding French replacements.

Thank you for your helpful suggestions. Unfortunately all the stickers are basically gone. If you can, please give me your impression. The frame without the fork weighs about 4lbs and 14 ozs. The number stamped on the BB bneath the paint is actually 73116. It is difficult to see clearly. There are no other numbers.

https://members.cox.net/phouda/PX-10/PX-10%20009.jpg
https://members.cox.net/phouda/PX-10/PX-10%20010.jpg
https://members.cox.net/phouda/PX-10/PX-10%20013.jpg
https://members.cox.net/phouda/PX-10/PX-10%20014.jpg
https://members.cox.net/phouda/PX-10/PX-10%20015.jpg
https://members.cox.net/phouda/PX-10/PX-10%20016.jpg
https://members.cox.net/phouda/PX-10/PX-10%20018.jpg
https://members.cox.net/phouda/PX-10/PX-10%20019.jpg
https://members.cox.net/phouda/PX-10/PX-10%20020.jpg
https://members.cox.net/phouda/PX-10/PX-10%20021.jpg

Again, many thanks.

It is a PX, from the early seventies/late sixties. The fancy Nervex lugs are the main clue here. Very clean frame, free of many braze ons (one of the reasons they make excellent fixed gears). The decals put it in the seventies (possibly sixties, but my 67 has a different scheme); the fancy lugs date it to 1973 or earlier. The serial number appears to be badly stamped on the frame, thus the missing #.

The lack of a BB and headset is somewhat problematic. However, you can stick an English threaded headset into the steerer tube and use a more modern fork (this is easier than hunting down a French HS and fork of suitable quality). The forks will likely be slightly different than the originals. Replacement PX forks are ridiculously priced when they show up on ebay. You can find bottom bracket cups without too much problem, or go with a phil woods bb. You'll have to remove the fixed cup (which is a stronglight) which can be a major pain on these bikes, if you elect to go with the phil woods. Otherwise, a decent adjustable cup and lockring will do the trick.

Poguemahone, thank you for the helpful information. There is so much incorrect data on the web, it helps to get a confirmation.

What about putting the flats of the fixed cup in a vise (very gingerly) and rotating the frame, using the whole frame as a lever?

"What about putting the flats of the fixed cup in a vise (very gingerly) and rotating the frame, using the whole frame as a lever?"...... I tried it in the past successfully, but this time I tried it again using a big wise at our Company machine shop, but there just isn't much to grab on, and the whole think just popped out. I think that someone was trying to take the cup off but was tightening it instead of taking it off. He also chewed up the BB a little. Next I will try the Sheldon's method using a bolt/washer/nut arrangement. If that doesn't work, I'll try a bike shop or just leave it with the old axle I have. I was going to use the Phil Wood ring arrangement, if I could. I am still not sure about the best way to go about the fork. One thought was to use a fork from non PX-10 bike of that era, which can be had inexpensively (the whole bike) or use a modern fork as you mention.

This fork would work quite nicely on that frame. The seller is a little Janus, but it is a fair deal for a fork, even after the shipping. ebay item # 3670081996.

"What about putting the flats of the fixed cup in a vise (very gingerly) and rotating the frame, using the whole frame as a lever?"

I've tried this approach on PXs with no success (you may have more). Because the fixed cup is not reverse threaded, they would really, really stick those suckers on tight at the factory. A Var 30 tool works, but it ain't easy.

Excuse my ignorance, what is a Var 30 tool?

A fixed cup tool. I'd try the other methods first; the vise method works sometimes, and I haven't tried the method Sheldon Brown recommends with the threaded bolt. The Var tool works on a similar principle to the Brown method, but is far beefier, with handles for leverage.

I finally removed the fixed cup. I tried the Sheldon's method with the 5/8th nut/bolt and broke the bolt. As I didn't need to preserve the pitted cup, I decided to cut into the cup at the surface where it meets the BB shell with a dremel tool and cutting wheel. That removed the friction between the two surfaces. I was then able to remove the cup quite easily. I refer to use the Phil Wood retaining rings and a Shimano Cartridge BB anyway, so damaging the cup is not an issue for me. Again, thanks all for your very valuable tips.

One oddity of the PX 10 frame, if you want to use contemporary derailleur (rear) is
the the thread is 26TPI on the rear dropout. If a current era der won't thread into
this, a 10mmx1.0 tap will recut the thread to current standards and do no damage to
the frame. If you have access to a simplex, be aware they are lousy shifters by
current standards. I believe I have set of Phil Wood rings, and an old ('70s era)
Phil BB left over from my Px 10 days. I committed the heresy of converting to
Shimano 8spd and repainting the PX before donating to my brother. I have no regrets over the conversion but cringe over the repaint job. OEM Peugeot paint stank however, if you rode the bike much. "Inoxyable" HA! Steve

Since I have a Sugino/SunTour drivetrain on my PKN-10, I cannot fault your transmission upgrade. You certainly are right about the quality and durability of Peugeot paint; my PKN-10 doesn't look that great, and my UO-8 is even worse, but I plan to keep both original, at least for now. I cannot justify spending several hundred dollars on a professional CyclArt repaint job, as I happily did for the Capo.