At first glance, Cycles Bertin seems to have been a smaller but pre-eminently French manufacturer and distributor of quality French bicycles and parts. The early Bertins are built with Vitus Durifort tubing, Huret, Simplex, Mavic, Ideale and other French brand name quality 
components. But look more carefully and you will find a company willing to
respond agilely to market demands as Columbus, Reynolds, Milremo and, yes, Shimano begin to appear on its products. Remember, while doing this, Bertin was simultaneously building mopeds and motorcycles, running a wholesale parts distribution company and managing a semi-pro cycling team and supporting independent racers using his products! Keep these facts and their complexity in mind when the details of Bertin’s women’s bicycle designs are discussed.
From early in the Post World War II period, Cycles Bertin had focused on supplying export markets as well as domestic demand at home in France. In addition to former French colonies like Morocco and Vietnam, Cycles Bertin sold its products in Britain through a close
association with Ron Kitching. (See this post for further details.) Although British buyers were becoming more open to the “Continental” fashion of road bike design, especially in regard to racing bikes, the market in Britain for sport and utility machines 
was somewhat less fashion driven and more conventional or conservative. Female cyclists in France, for example, rode mixte frames around town or on randonnees and diagonales but diamond frames if they raced. In Britain the double, parallel down tube design remained the dominant style of women’s bike other than for racing or sport. The French catalogues called them the “Dame Anglais” or English Woman’s style. As well , there were “Mixte” frames and a third style often found on utility bicycles but also on women’s sporting bikes called the “Dame Berceau” or Woman’s Cradle frame.
The English style frame has self evident advantages for a woman mounting or dismounting while wearing a dress, skirt or long coat as would be expected of a utilitarian, female cyclist in the 40s, 50s and even much of the 60s. Although the step over is low, the 
convenience of the design is high even if it badly compromises frame strength by effectively removing the top tube. The lack of an effective top tube or extra stays makes the design prone to twisting under vigorous riding. Ultimately, not a big problem for utility cyclists but limiting if sport riding is to be done. The bicycles themselves were sold in France as well as the British market and the advantages proved to be long lived. The example to the right is from the 1990s
and speaks volumes to the durabilitity of the basic design concept and the advantages it conveys to the casual or utilitarian rider. There was a modified version of this style as well with a flattened section in the upper down tube to provide more bracing to the frameset. The photo of this green coloured variant shown to the left of the page comes from the 1980s and demonstrates that tinkering with and modification of the design continued consistently as long as production lasted. 
The other photo, of a late 1990s Bertin production bike, shows that the adoption of oversized aluminum frame
tubing, gussets and TIG welding allowed designers to restore lost torsional strength to the frameset and still keep the advantage of the step through “Dame Anglais” design.
The Mixte style of frameset was offered in parallel with the English Woman’s style and the Cradle frame design. A major advantage of the mixte is that the design restores much of the lost torsional rigidity of 
the frame by attaching the narrow diameter twin lateral tubes to the seat tube as they pass and by adding a third set of stays to the back of the bike. Because the twin laterals are small in diameter, they are
heavier than an equivalent larger diameter top tube would be. As well, more weight is added by the extra set of stays in the rear triangle of the frameset. Despite the extra cost of the mixte design caused by the special head and seat tube lugs (see photo to the right), extra tubing and special cable routings (see photo below), the mixte remained a viable sporting bike as can be seen in the 
white randonneuse shown above with its dropped bars and guidonnet brake levers. Step over was compromised as was minimum weight but the frameset had the potential to be a useful multi-purpose bike.
The Cradle, the third frame design focused largely on women (men did ride the mixte as a town bike due to the extra clearance for rapid dismounts in traffic), was frequently seen on bicycles with a clear utilitarian focus. It was largely a compromise between the two other designs being a basically “bent” mixte that restored some of the lost step over height so evident in the English woman’s frame design.
Sometimes the twin lateral went directly to the rear dropouts after they bent above the bottom bracket as shown on the green Bertin in the accompanying photo. On a different 
occassion, the lateral tubes swoop down low in a curve only to gracefully curve again in order to meet the junction points with the dropouts as seen in the photo of the Bertin C 10 to the left of this text. Noticeable as well, is the fact that the utility bikes are equiped with Stumey Archer 3 speed hub gears. French enthusiast cyclists decried these as “friction boxes”and refused to ride them unlike their English equivalents. However, on a utility bicycle, an enclosed gear system was something that appealed in both markets.
Another noticeable characteristic of these bikes is that they usually come fully equipped with rack, fenders, lighting, chain guards, sometimes even with dress guards to prevent soiling madam’s clothing while coming back from an errand. As well, these classic, utilitarian cycles manage to offer all this functionality with a panache and pleasing style that quite embarasses modern utility bikes such as the welded aluminum Bertin shown earlier in the post.
These three frame styles offered by Cycles Bertin were in no way definitive. Mixtes could be ordered from the factory with hub gears. English style bikes could and did come with derailleurs as might Cradle design framesets. Andre Bertin was a pragmatist who was willing to provide what a market might need whether it was 650B or 700C wheels, utilitarian accessorizing or pumps and tool kits. Remarkably, while juggling the huge responsibilities mentioned above, he was able to do it with a sense of style which leaves these classic old bikes desirable even today.
Bertin Classic Cycles 