Hello,
I am wondering what tubing could my frame have. It didn't hava any decals, neither badge, neither anything embeded (except for the number 135 on the bb). The dropouts are plain, french bb, clearence for mudguards and rear spacing around 123mm.

I don't know what else can describe the frame... Any info accepted.

Don't know how you'd tell about the tubing. The lugs appear to be Prugnat 62bis, which would indicate a high end frame. Dropouts looke stamped rather than forged though. Is the tubing french dimensioned too (26mm top tube rather than 25.4, etc.)? Cool frame - pretty wrap around stays!

Don't worry about the tubing. There will be some guide as to the price point based on the seat post size. Decent Prugnaut short point lugs. More attention to the seat stay tops than even many claimed 531 frames. Best clue to the parentage is actually the shifter stop on the down tube. The lack of forged dropouts is actually the most surprising.

+1

The wrapped seta stay tips on the seat lug seems to suggest an English bike, but it having a French (threaded?) BB says that it isn't
But, If it is indeed French, then it could be anything from either some sort of Hi tensile carbon steel "house" tubing made by the bicycle company themselves (Like Peugeot's Carbolite 103) or Vitus (172, 888..etc) or Reynolds (531 mostly for older French bikes). It could be the latter two as the frame has quite nice lugs on it. Any pics of the fork and the fork crown we can look at??
Columbus did also appear on French bikes, but that was later in the 80's for some of the higher end/"team issue" racing models for different French companies....mostly SLX.

Chombi

Always Durifort too.

is there a shifter stop on the DT...I can't see anything?
Looks very interesting. Seat post size will be telling. The stay end treatment looks more "Swiss" than "French".
No fork?
Durifort = Vitus...more-or-less...just another timeframe.

If the bike is French, the tubeset will most likely be either from

- the Ateliers de la Rive, who produced the Durifort and Vitus-tubesets, or
- Reynolds.

No, they are different and were also produced at the same time: https://www.yellowjersey.org/vitus.html

Could be Excelle tubing. Framebuilders liked working with it.

Measure the seatpost diameter, that should indicate the wall thickness which can give a clue as to the tubing origin.

That I doubt, Excell was marketed to top end small producers. If the bike had forged dropouts, then I would be more open to that possibility.

What I meant by that comment is that they were from the same company, and that Durifort was more common (as the brand they sold) prior to the Vitus brand.
But thanks to the catalog scan you provided, it's clear they also retained the "Durifort" brand (as their budget tubing, 888) into the "Vitus era". Also interesting to see that this was available in "Imperial" dimensions as well as metric...yet another thing I didn't know.

This prompted me to do a little digging and I learned much more than anybody wants to read here about Ateliers de la Rive, and their tubing products, from both Chas Colerich and this from Norris Lockley...which I will share since it's just shy of enormous:
"Ateliers de la Rive, a company based on the outskirts of St Etienne, =
France, started making tubes in 1931. In the early post WW2 years their =
premium tubing was called Rubis, and widely used by French quality frame =
builders. Around this time Urago, in Nice, started using DURIFORT - the =
tubing maker's base set of plain gauge tubing for their "Debutante" =
model, and "Vitus" a lighter double-buted set, for their better frames, =
alongside Reynolds 531DB.

Durifort continued as a set well into the 1970s by which time Ateliers =
de la Rive had introduced Vitus 171, a series of double-butted tubes in =
chrome-molybdenum steel, with wall thickness generally of 1.00 / 0.7mm. "

Thanks to everyone for the opinions and here are the rest metrics...

top tube outer diameter: 26mm
seat tube outer diameter: 28mm
seat tube inner diameter: 25.4mm
bottom tube outer diameter: 28mm
bottom bracket width: 68mm
also no fork...

and now I am checking if a french bb screws on.
an italian bb did not suit at all

The tubing dimensions are consistent with a French frame built with a hi-tensile steel.

just found a marking on the right side of bottom bracket, it says EDA

and I am not sure if bb is french or swiss, as I still can not unscrew the right cup



Thanks again for the replys!

Look/feel inside the BB shell and you might be able to see the treading direction of that side you cannot remove the cup from....

That's a Stronglight fixed cup. It appears to have a single ring cut/engraved into it. If so, that indicates French threading. You may want to strip the paint off of it, to be sure.

the EDA BB shell is a bit mysterious: it mimics the logo of the more common RGF (Gargette Brothers) shell, and some folks think it might be another brand from them, but the EDA shell has shown up on Jeunets, Louison Bobets, and Jacques Anquetil frames as well as some Raleigh Pros, too! I'd be surprised if it had Swiss threading, but since they must have made it with BSC threads...anything's possible!

I love this episode of Bicycle Detective! When's the next installment?

Sorry, didn't want to sound teaching. Just thought that you thought it would be the same tubing given just a different name.

I agree with T-mar. The seatpost size indicates high tensile steel.

That doesn't mean that it can't be built up into a nice-riding bike. The French had a way with gas pipe. It can be expensive to build up a forkless frame unless you have a lot of spare parts on hand.

I agree completely. The French in the 60's and 70's often made bikes that rode beyond their elements.

since I'm still learning, I appreciate some "teaching"...but also felt the need to explain myself better
Thanks!