While restoring my 1970s Bertin C 37 a few years ago, I noticed that it differed in frame details from any C 37 I had 
previously seen, including in Bertin catalogue photographs. At the time, I gave it little consideration since catalogue photos are never definitive. Eventually, I ran across an article on Classic Factory Lightweights which discussed the work and career of the French frame builder Bernard Carre. In collecting and editing information from Norris Lockley, the retired frame builder of Bespoke of Settle, the editor of Classic Factory Lightweights gives an overview with photos detailing Carre’s career and style. There are details in the article of the 3 different levels of build and finish common to Carre’s production.
Photo Credit: Classic Factory Lightweights
Having read the details of the article, I was struck by the similarity between the Delcroix linked to in the article and my own Bertin C 37’s construction. The seat stay caps and binder bolt were identical (except for the B. Carre engraving), the rear brake bridge reinforcements were alike, the lugs
and crown were almost identical and the fish mouth cut off and finishing of the stay and fork ends were the same. As well, other bikes like some factory team Gitanes and Lejeunes from the late 60s or early 70s had remarkably similar frame construction details. The whole issue was quite intriguing so I began to actively seek out information on Bernard Carre. Shortly after I began, two readers, Richard and Bob from the U.S., contacted me about their personal Bertins. They were seeking to confirm the model identification and the period of their bicycles’ construction. They both owned C 37s but Richard’s was especially interesting as I will explain later.
First, some of the circumstances which created the Carre – Bertin connection. In 1973, the original,
post World War II Bertin factory was totally destroyed by fire. This was ill-timed in the extreme. North America was in the midst of a record sale of bikes to fill the demand of the new cycling fitness craze. There were about 64 million bikes sold in the U.S. between 1970 and the boom’s end in 1975 with 1973 being the peak year at 15 million bicycles. This was the year that Bertin no longer had a production facility. To stave off disaster, which would have entailed loss of a year’s sales and the Bertin dealer network, Andre Bertin contracted with volume builders like Manufrance for low-end bikes and with Cycles Bertin Belgium for much of the mid-range. What was needed was someone to build the top of the range bikes like the C 37, especially those for the factory supported racers. It was this product gap which formed the basis of the commercial relationship between Bernard Carre and Andre Bertin.
Bertin Classic Cycles 