I posted this as a tack on in an old thread, but now I've taken some proper pictures so I'm starting a new thread.

Can anyone tell me anything about this frame? I picked this up from Craigslist last week. I think it's a Bertin. I'm guessing mid 70's. The bottom bracket is French threaded. It has Campagnolo 1010/1 dropouts. According to the lugs, the head tube and seat tube angles are both 72 degrees. The seller gave me some Belleri handlebars and a Belleri Belri Course stem with it, but I have no way of knowing if those were original to the bike. The seller told me he got it from a friend who bought it for the crankset. He didn't remember the brand, but it was at least nice enough to be worth buying the frame to get. I don't know much more than that.



















Can anyone help me narrow down what this is? [MENTION=61614]verktyg[/MENTION]? [MENTION=297217]bertinjim[/MENTION]? Anyone else?

A couple of other minor data points: the frame weighs 2080 grams/4.6 pounds, the fork weighs 800 grams/1.75 pounds, and there is a visible seam on the inside of the head tube.

Seat tube OD (probably 28.0mm for French) and ID (26.4 or 26.6mm for butted moly steel, smaller for plain gauge)?

The frame looks very servicable. Just a bit concerned though with the seemingly crushed chainstays where a sidestand clamp must have been installed....

Hi, Andy-

The Belleri bars and stem might be OEM but Bertin also used Milremo and Atax/Philippe products. Your frameset looks to be a Bertin possibly a C 34 from the Vitus Durifort frame and fork. The fork would have a visible seam in the steerer as would the main tubes and stays since Durifort was a seamed low alloy steel tube set. The crimped stay caps were characteristic of Bertin's Durifort framesets. The lug style is about what would be expected of an early to mid-80s frameset.

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Somewhat later than I would have guessed from the tack on image posted the other day. IIRC this BOCAMA Professional series lug pattern launched ~1975-76.

Interesting that this Sport ends set lacks the spring hole for the Sport rear mech. Set must have been produced no earlier than 1973.





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OD is 28mm, ID is 26.4. I wasn't expecting butted tubing, but I have a 26.4 seat post in the garage and it fit.


The flattening of the chainstays is even enough that I kind of think it may have been part of the frame production. At the very least it seems to have been done more intentionally than carelessly.


I thought 80's based on the bottom bracket braze-ons, but the lack of top tube brake-ons kind of pulled me the other way. I wasn't sure what to make of that. I saw a 1972 Bertin brochure in which even then most of the bikes had some kind of brazed top tube cable guides. Were there models that lacked that into the 80's.

I can't see a seam in the steerer or seat tube.

(BTW, your blog/website is exceptional! Thanks for all that work!)


It didn't even occur to me that the lug cutouts were standard to the lug itself. That's interesting.

In the other thread, verktyg mentioned that around 1976 the market was pushing back against stamped dropouts. Unless the Campagnolo brand offered these an exception we may be narrowing in on a date range here, no?

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wrt lug cutouts -

BOCAMA would offer the same lug pattern with four differing cutout designs. see r1, r2, r3, r4 in this illustration:

C34 is I think a very good guess.
As written elsewhere, it was not that difficult at all to order specific details for even reasonably small orders.
12-25 bikes of one type could achieve that.
As the frame has been repainted, the braze-ons are suspect for original, but could be factory, leave them in place.
The drive side dropout has opened up under the pressure of a solid axle fixing nut no doubt.
If it was me, I would straighten the slot (12" crescent wrench on the derailleur mounting tab, done that)
Strip the paint and get a washer brazed in behind the end, cut away the section then filling the slot.
Maybe even do the other side of the frame too.
Refinish it, there are a number of colors it could be, graphics varied, and a number of examples with similar lugs to give a reasonable guide.
No doubt you have French threading here.
These ride very well, Bartin was late to the steep geometry party, and we are the better for it now.

The chainstay crimps are from an Esge kickstand no doubt and not factory, for bikes that were expected to receive a kickstand or side stand, Bertin brazed in a formed plate below. The dents are not aesthetic, but I really doubt they will cause a problem beyond that.

This bike was probably built for 700c wheels but of generous clearances, Mafac center pull brakes suggested.

+1 to what repechage said. You will probably find Mafac Racers, or Competitions would be a good fit for brakes. Check the brake drop with some 700C wheels as Racers were frequently OEM on the mid-priced Bertins and remain outstanding stoppers with a good set of Kool Stop inserts. New decals are readily available from VeloCals if a repaint is in the future. Don't worry about the tubing seam as they can be difficult to see. Maybe try again with a flashlight looking down the tubes. And thanks for the kind words regarding the site.

Thanks, everyone! The number of people on this site with deep knowledge of Bertin really amazes me. I don't see them very often, but you guys obviously know your stuff.

Yeah -- with a member named bertinjim, what do you expect?

I learn something new every time I visit this website.

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Hello again Andy,

You wrote:

"In the other thread, verktyg mentioned that around 1976 the market was pushing back against stamped dropouts. Unless the Campagnolo brand offered these an exception we may be narrowing in on a date range here, no?"

Unsure of the direction of reasoning here. The 1010/1 ends set is shown in catalogue nr. 12 of 1953 on page 19. It still appears in catalogue nr. 18 of 1985, on page 34. Do not see its presence or absence as much of a trend/fashion point.

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Those Campagnolo 1010/1's I would call semi-forged. Coined, the edges on both side show a semi radius. They are of thinner material than the ubiquitous Campagnolo forged design. No room for an adjuster screw. My guess would be 4mm thick from memory. About the same as the vertical dropouts. On those often the top builders brazed on a washer to the inside of the axle slot end. It provided more room and clamping dimension, the axle was less likely to overextend and interfere with the skewer.

So the reasoning depended on (1) my perception that the 1010/1 is a stamped dropout, (2) your statement that it must have been made no earlier than 1973, and (3) verktyg's statement that people didn't want stamped dropouts much after about 1976. Even at that, it wasn't water tight reasoning -- more like following a clue to see if it led anywhere.

Cosmetic, from my experience. Unfortunate, yes, but for a rider, who cares?

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Thanks for the response Andy!

wrt verktyg's observation -

Keep in mind that with his long view and vast experience in the trade he is writing here of a trend; the way things were heading at that moment in time. Situation not like a valve or gate opening/closing but rather a direction.

At the commencement of "the boom" in 1970 most shoppers were content to purchase a Peugeot U08/Raleigh Grand Prix/Mercier 100 type cycle. As time went forward and they read BICYCLING! magazine and later on BIKE WORLD magazine they became more sophisticated in their bicycle tastes. By 1974 we had the phenomenon of cycles from France being imported with gear systems and alloy cotterless chainsets produced in Japan. This would have been unthinkable two years earlier. Shoppers were beginning to look for alloy cotterless chainsets, alloy wheel rims, tubing transfers, gear hangers, etc. Ideally they might have liked an all Campag machine but only a few were willing to remit the fare. So we had the phenomenon of something in the middle.

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