Bertin Tandem

In mid-May, I was contacted by a French reader of the blog looking for help in identifying a tandem that he had just purchased. It was a Bertin tandem, which is unsurprising on this blog, but what a unique bertin

Map credit: Wikipedia

Map credit: Wikipedia

Bertin it turned out to be. Loic wondered if it was a tandem built in St. Laurent-Blangy as the Bertin head badge listed a different location. The Cycles Bertin badge showed the small town of Rheges as the location of the business which constructed the tandem, not in the Nord Pas de Calais but in the Aube departemant to the south and east. Surprising really, as Rheges has a population of about 240 people and does not seem to be a Bertin 50s Headbadgehotbed of industrial production. The Andre Bertin badge is radically different with its tricolour and eagle motif. The tandem is in the profile photo which follows and you should look very closely at it.

 

 

bertin2

I would direct your attention to the horizontal boom tube which joins the captain’s and the stoker’s bottom bracket shells and to the non-existent front chain wheel. Instead of an eccentric front bottom bracket and a chain wheel to connect to the stoker’s crankset there is a vertically ovalized and fillet brazed tube to enclose what I believe is a shaft drive to the stoker’s crankset axle.

The design is well thought out for the pre-WW II to 1950s when its equipment was produced. There are brazed on Jeay roller cam brakes, hub brakes in steel hubs on 650 B rims and a Cyclo derailleur on the rear with a later single sprocket instead of the expected 3 or 4 cog freewheel. The cranksets are steel with a rear double. The brazing looks very clean and the bike was painted a lovely shade of green with the beautiful pinstripes so characteristic of the era. Below, are close up photos by Loic. I think you will find them fascinating. (Double click on photos to enlarge)

Front Drum Brake

Front Drum Brake

 

Jeay Roller Cam Brakes

Jeay Roller Cam Brakes

 

Stoker Crankset

Stoker Crankset

Cyclo Shift Lever

Cyclo Shift Lever

Seat Cluster with Custom Rack Mounts

Seat Cluster with Custom Rack Mounts

Cyclo Rear Derailleur

Cyclo Rear Derailleur

 

 

Rear Axle/Drum Brake

Rear Axle/Drum Brake

Drum Brake and Reaction Arm

Drum Brake and Reaction Arm

 

Head Tube Junction

Head Tube Junction

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Although this is a Bertin tandem, it seems unlikely to be a tandem produce by Cycles Andre Bertin. Note that M. Bertin’s business is not called Cycles Bertin like the tandem but always either Cycles Andre Bertin or Cycles A. Bertin as seen on the ad below.

Advert Bertin Milremo

Nonetheless, this is a fascinating and unique machine produced, it seems, by the other Cycles Bertin.

 

 

 

 

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