May 28 2016

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

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 hotbed 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.

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

Jeay Roller Cam Brakes

Stoker Crankset

Cyclo Shift Lever

Seat Cluster with Custom Rack Mounts

Cyclo Rear Derailleur

Rear Axle/Drum Brake

Drum Brake and Reaction Arm

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.

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

Oct 13 2012

A Bertin Tandem

overview

The work on a site like this has behind the scenes maintenance that the reader is seldom aware of. Last December, I was checking links and updating photos in the Models section of the site. I try to have as clear and representative an illustration of a model as I am able to find and had located a Bertin tandem T 2 photo.

Previously, I had a black and white catalogue photo so the colour image was a real improvement in quality and clarity for readers attempting to find information. The change was made and shortly thereafter I was contacted by Adrien D. from France who had just purchased that same tandem. He was hoping to find information on the bike as he was planning to tour on it with a friend and really wanted to know more about the bike to which he was entrusting his vacation. It was a mutually beneficial moment as he was enthusiastic about his new purchase and more than happy to provide me with numerous photographs of the bike while I was able to provide him with specifications and a copy of a contemporary road test.

As well, Adrien explained the changes made to the tandem in preparation for the tour and was also kind enough to provide photographs from the actual trip itself. I extracted his permission to do a Feature Bicycle post on the topic for some time later. Adrien, it has turned out that “later” is much later than I had originally intended but here it is.

details

Original configuration as purchased

As configured for tour.

frame

Frame Details of Laterals

brakes/shifters

Braze-on Mafac Cantilever Brakes

Atom Drum Brake and Reaction Arm Attachment

Dual Cable Mafac Brake Lever

drivetrain

Details of TA Triple Crankset

Huret Allvit Rear Derailleur

handlebar/stem

Philippe Alloy Stem and Handlebars

Once Adrien had the upgrades and modifications to the tandem ready, he and a friend took the machine on an enjoyable tour through Southern England and Wales. Hopefully, there have been other equally enjoyable occasions since that first successful trip.

The Bertin T 2 on Tour in Southern England

Jul 1 2010

Featured Bike # 3 – Donovan

Overview

The third featured bike is, once again, a modern Bertin. Donovan, one of this site’s correspondents has purchased and built up a NOS frameset which visitors will see below.