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R.T. Jansen was a custom framebuilder in the late 1970s, specializing in high end touring bike in the French style. I believe he was based in New Hampshire. Sorry, I don't have any additional information on this builder, but thought that some folks might be interested in this rare marque.
This bike was custom built for an old friend of mine in the late 1970s, by R.T Jansen. It is the actual bike shown in the catalogue.
Although the frame is American, the bike is very much in the French style, with mostly French parts.
It generally represents the state-of-the-art in serious touring bikes of that vintage.
The frame is mostly fillet brazed, except for the bottom bracket, which is lugged.
It has Campagnolo vertical dropouts.
Dimensions:Seat Tube: 49 cm center to center
Top Tube: 55.5 cm center to center
Chainstays: 43.5 cm center to center
Wheels650b (584 mm) French rims, probably Mavic or Wolber 58.
Maxicar sealed bearing hubs.
36 spokes front and rear. The wheels are true and undamaged.
Vintage Wolber 650B tires are in good condition, tubes hold air.
5-speed freewheel 14-30 teeth.
Drive TrainTA crankset 52-44-30 teeth
Phil Wood bottom bracket.
SunTour VGT rear derailleur
Simplex Super LJ front derailleur SunTour Barcon handlebar end shifters
Other PartsPivo stem (8 cm)
Drop handlebars, probably Pivo
Mafac cantilever brakes
Idéale #42 saddle*
Lyotard Marcel Berthet #23 Pedals*
*The bike came to me without a saddle or pedals, I installed a saddle and pedals that I had on hand, items which seemed appropriate to me. The pedals are fairly heavily used.
AccessoriesAluminum fenders/mudguards, brand unknown, probably French.
Front and rear luggage racks, brand unknown, probably French.
Sanyo Dynapower bottom bracket generator/dynamo with internal wiring
FlawsThe front fender is slightly bent.
The lights do not work, but I have made no attempt to service them.
The tail light is loose on the rear fender.