Hi,
I've got an old peugeot i'm switching to single speed. I'm pretty sure it's a 60s-70s PX10, given decals and comparisons. I've looked on the PX10 history site as well as the site with the vintage Peugeot catalogs and still am not sure what to make of the model for sure.

Clearly the key info is stamped into the BB shell, but that's where I'm confused. "RYF4" is clearly stamped on the shell. Further down the shell, a mark that's like a skinny sideways C next to a regular looking C is imprinted too. It seems from what I've read, all serial numbers consist of more letter/number, yet that's all that appears on the shell. Also, the RYF4 doesn't even seem to correspond to any part of serial # codes I can find.

When I bought the old thing, it had simplex and suntour gear. It's still got cottered crankarms. It had a Pretscher(that's very likely not the right name) rack and kickstand. A bike license sticker dates it to at least 1978. Any educated guesses for this "RYF4" would be greatly appreciated. Thanks.

Post some info on it....I'm sure we'll figure it out.

Cottered cranks would suggest a UO-8 or similar - PX-10s had Stronglight cotterless cranks - unless, this is some kind of weird downgrade!
The rack you refer to is Pletscher, which was the standard rat trap rack back then...

Thanks but I'm not sure what info to add: simplex derailleurs, suntour shifters, normandy hubs. Hope that helps.

Thanks for the reply--I guess it could be a UO8. It would be petty wierd for someone along the way to have downgraded to cottered cranks...

The single key to a PX-10 is chrome on the rear seat and chainstays. Chrome on the stays doesnt mean its a PX-10 because other high ends had it but abscence of it automaticaly rules out it being a PX-10.

miamijim, I've got no chrome in the back of the bike! Thanks for your help.