Bertin Vintage Festival

I received an email from Christophe who lives in Lille. He wanted to share news about an upcoming Cycles Bertin based retro cycling festival taking place at the end of June. It will be held in St. Laurent de Blangy, near Arras. The poster is below.



DO YOU HAVE AN ORIGINAL  BERTIN piece of memorabilia (BIKE, CAP, JERSEY, …)?


This free family event is open to all and offers two courses where everyone can enjoy the conviviality of this mythic brand.

Inspection workshops for your Bertin bike will also be offered for free if yours requires a small adjustment. Bike loans can be made according to availability.

An exhibition about Cycles Bertin will also be held in the former factory of the firm, (Rue Georges Clémenceau) in a retro atmosphere.

                                                 DOWNLOAD THE REGISTRATION FORM

The link above for the downloadable registration form is active as of May 1st, 2018. Click and it will take you there.  EN FRANCAIS – ICI .



Belgian Bertins and Reynolds A Tubing

Cycles Bertin Belge and Cycles Bertin France were two different companies connected by family ties and the circumstances of the post WW II European economy. There is a three-part series on the blog with more details located here which explains the origins and product offerings of the Belgian firm. One of the anomalous things about the Belgian Bertins was the use of Reynolds tubing in the framesets of the light weight/racer style of bikes.

Bertin Sport Bike With Butted Reynolds A Main Frame


In the early days, perhaps the 60s and 70s, higher end Belgian Bertins had 531 framesets but mid-line bikes had frames or framesets made of Reynolds A quality tubing. Probably due to tariffs in the immediate post war period (pre-EU), Cycles Bertin Belge did not use much in the way of French tubing like Vitus or of French components like Mafac, Stronglight and so on. Instead, they used Reynolds, Ishiwata, Weinmann, Sugino and Shimano. The result was a line of unique products which did not always parallel the offerings of the French company. What puzzled me when writing the earlier series about Belgian Bertins, was the company’s use of Reynolds A tubing. I had never heard of this product in the  45 years I have been cycling as an adult.

A Google search revealed a math text-book worth of numbers: 531, 453, 500, 708, 753, 525, 653 and on and on. No Reynolds A. The only places I saw the identifying label was on photos of Belgian Bertin frames and the occasional other European bike like Zeus. Having little luck on-line, I emailed Reynolds Technology to ask about their former product. I received a response from one of their technicians who helped clarify the matter. Reynolds actually made two similar products in the 1960s to 1970s called Reynolds A and B tubing. Keith N. of Reynolds, pointed out that these tubings were mild steel/hi-tensile in nature with about 60% of the ultimate yield strength of Reynolds 531 which would put A tubing at the after brazed strength of around 27,000 psi compared to 45,000 psi for 531. Keith also pointed out that the tubing was a combination of cold drawn seamed tubes and seamless tubes. As well, they were available in 3 different gauges and in butted and plain gauge sets. I do not know if the lightest sets were A and the heavier sets were B or there was some other specification for B series tubing. He also provided scans of the Reynolds technical pages for Reynolds A and B. See below:




Reynolds used SWG thickness measures and I have converted these to Metric measurements for the lightest Reynolds A set and then added them to a chart to enable comparison with other lightweight hi-tensile and classic lightweight tube sets.


The chart shows that Reynolds A was certainly competitive in weight and strength against products like Columbus Zeta, Vitus 888, Vitus Durifort (the butted version of 888) and Falck B and Libellula tubing. It was also not far off the standard tube sets like 531 and Columbus.

Like 531, frame decals were used to identify the Reynolds A tubes built into a frameset. Some were for main tubes only:


Other framesets were built with hi-tensile butted main tubes with Reynolds A also in the forks and stays. Those tubing decals look oddly familiar:


Also, like 531 decals, Reynolds A decals were available in French and English. Eventually, either because of the TI (Tube Investments) takeover of Raleigh in 1960 and a rationalization of product lines or due to declining demand for a budget quality tubeset easily replaced by 531 plain gauge, by the 1970s Reynolds A and B were gone. Their place on Belgian Bertins was taken by Ishiwata tube sets. But Reynolds A an B‘s niche was not forgotten. In 1980, Reynolds introduced SMS tubing (see the spec chart above) a full, welded  hi-tensile set which was taken up by Continental manufacturers like Elvish, Gitane, and Zeus.

It was discontinued in 1982 as Reynolds 453 was introduced into a rapidly innovating tubing  market jammed with alternatives like chrome-moly, aluminium and titanium. It was to welded aluminum that Cycles Bertin eventually went for their line of bikes leaving behind forever the days of Reynolds steel framesets.


Bertin Advertisements 3


As one would expect, Cycles Bertin advertised in professional journals, Cycle sport magazines and sports papers such as Le Cycle as can be seen in the second installment of this series on Bertin advertisements. In addition to that type of advertising, Cycles Bertin published its own product catalogues such as the example below from 1976:



As well, after the founding of the Milremo parts and accessories  brand in the late 1950s in conjunction with Ron Kitching, Cycles Bertin published parallel Milremo catalogues illustrated by Daniel Rebour and his brother, Rodolphe. Typically for the two brothers, Daniel would do most of the technical line drawings and Rodolphe would produce the covers and the occasional figure drawing inside the brochure. Below is the cover illustration of the 1976 Milremo catalogue which I received at the same time as the 1976 Cycles Bertin catalogue shown above.



For those of you who like Rodolphe’s illustration, I have added a second version of the cover cropped of extraneous text materials. The two Rebour brothers made an effective pair in enabling Cycles Bertin commercially.





LED Conversion for Dynamo Driven Bike Lights

It was at the end of December in 2016 that the short days, rapid sunsets and long nights finally prompted me into some kind of action. My Bertin C 37 had been converted to a randonneuse by the previous owner who had added vertical dropouts, brazed-on centerpull pivots, dual bottle cages, cable guides and shifter braze-ons on the downtube. Oddly, he had not added provision for generator driven lighting which was mandatory, along with fenders, under the randonneuring rules at that time.

The bike was purchased from Mike Barry at Bicycle Specialties in Toronto and it was there that a generator braze-on on the non-drive seatstay was added and the frame was drilled for internal routeing of the wiring for the taillight. Honjo fenders were added (to allow wire routeing through the rolled edge of the fender) and provision was made for a combined tail light/reflector on the rear fender. I assembled the bike with a Soubitez 6V 3W bottle generator and a matching front Soubitez headlight with 2.6 W screw base front halogen bulb and a 0.4 W rear halogen bulb. The front light was attached to the left side Mafac brake pivot bolt via a custom Mariposa tubular cromo bracket. The headlight wire went back to the lower head lug, through a hole drilled in the lug and frame and out the drilled bottom bracket, up inside the rear fender edge and into the generator. The fender stay attachment shown in the taillight photograph is a custom Mariposa style stay which uses cromo tubing and braze-on fittings to produce a rigid, stable and rattle free attachment for the plastic fender light/reflector combination. The single taillight wire goes from the generator to the inside of the rolled fender edge and down the fender to the taillight housing.

The result of all that plumbing was not impressive even if state of the art for the period. There was a warm, yellowish light puddled on the ground about 3 meters in front of the bike and a nice bright taillight. There was a reason all those old French randonneuse bikes had big, D cell battery powered flashlights on their front racks.

Visibility for this rider was poor at best and the lights and rear reflector really just acted as markers to let other road users know I was out there. It was obvious that a lighting upgrade was necessary regardless of the fact that I seldom ride at night anymore.

There has been a great deal of progress with LED based bicycle lighting in the last decade but much of the “modern” headlight and taillight designs are aesthetically incompatible(read: ugly) with older, classic bicycles. So, the obvious thing to do was to search out some kind of LED lighting which would be retroactively compatible with my current Soubitez lighting.

One of the great benefits of the older style of halogen/incandescent lighting was the single wire format with the circuit ground being through the frame. So, what I needed was a conversion to LEDs that was a simple bolt-on or screw in with LEDs being available on line.

A simple on-line search was immediately fruitful. Compass Bicycles in the USA offers a red LED rear light in 0.35 W with a built in stand light feature. As well, a front LED conversion light was also available through Bikeco in the UK.  The NL 432 LED was rated at 120 Lumens and was compatible with the 6V output of the Soubitez generator. One of the drawbacks of the NL 432 was the necessity of using a regulator to avoid overloading the front LED. It was possible to add a regulator to the circuit but to keep the conversion simple, I deliberately chose to use the Compass rear bulb. This contains a built in standlight function which avoids the need for a regulator and allows a simple plug in and ride approach to the bulb conversions. Bikeco offers both screw-in and push-in LED bases to facilitate the conversion.

On the Bertin, the conversion was quite straight forward. The front Soubitez headlight levers open and the reflector pulls out as it is a simple friction fit. The bulb/LED base pops out

of the reflector and the halogen bulb unscrews and the LED screws right in. Note that the Bikeco LED has a conical projection on the top of the LED. This is a collimnator which disperses the LED light from the same point relative to the reflector that an incandescent bulb filament would. The rear LED is not configured like this as there is no need to worry about focus as there is with the front light. The standlight  circuit is integrated into the rear bulb base and once the bulb is screwed into the base there is no other action to take. My installation was easy as the rear light lens unclips from the reflector housing, the old bulb unscrews and the new LED simply screws in as a replacement. The lens just clicks back into place when LED installation is complete. The result looks just like this:


Road Test:

Once the bulbs were installed, the bike was taken out and test ridden. Once the generator was activated, the two LEDs immediately came up to full brightness. There was no gradual increase of intensity as I experienced with halogen bulbs just immediate full function with no fall off in brightness even riding slowly at walking pace. The slight hum from the generator was the same as previously with the halogen bulbs.

The beam intensity was significantly brighter than the previous halogen headlight but I still would prefer more light. The stock Soubitez headlight cast a bright spot in roughly the same area as the previous halogen lamp and threw some light down at the base of the front wheel. The headlight colour is a bright white light and is easily visible from the front. The light intensity is sufficient around town and gives sufficient light to the front if one travels slowly. It would be readily possible to out ride the light. There was no diminution of the light after a half hour ride which indicates there was no over volting of the LED.

Caveat: Consider that my comments about light intensity and visibility are filtered through 70 year old eyes which have reduced night vision capacity.

The taillight was excellent. The red light was highly visible from the rear (easily from a city block away  under street lights) and the standlight was at full brightness for seven minutes with lesser intensity for another four or five minutes. Outstanding.


The conversion is worthwhile if you need a classic style lighting system for intermittent use. If you are regularly commuting in the dark, I do not believe that this would be sufficient for your needs. It would definitely not be adequate for fast riding or downhill use on a road bike.