I am in need of a Maxi Tandem rear drum brake (tambour) Super Grand Tourisme, 115mm, duralumin flanges and 40 holes, in good usable condition, for the René Herse tandem featured in the next post. The steel version is not suitable, and it has 36 holes. Please do let me know if there is one available to purchase.
My wife has recently undergone major surgery for a tumour in her head and she will be unable to ride a bicycle for many months.
I am trying to get the tandem finished so that she can enjoy some gentle short rides on the back of it as she is recovering.
I would really appreciate any help or advice on where to find one of these.
It looks like this….
Photo’s courtesy Alexander March
Raymond Bon was one of René Herse’s team riders. In the late 1940’s he designed the Spirax derailleur, seemingly quite a revolutionary gear. The main principle of the design was to maintain even chain tension throughout the gears.
One of the disadvantages of the Cyclo gear, as used by most touring cyclists of the period, was that chain tension was uneven, being maintained only by the long spring attached between the derailleur and a lug on the chainstay. The Cyclo also had a ‘dual’ cable arrangement which is a little tricky to set up. Bon did away with both these disadvantages in his design. The gear still moved along a rod with a helical groove, like the Cyclo, but the visible flat coiled spring returned the gear along the rod using its tension. This meant that only a single cable was needed for actuation. There was a second coiled flat spring concealed inside the metal casing, which maintained the chain tension.
It could handle a wide range of gear and chain-wheel sizes, 12 teeth at the rear and 20 teeth at the front. The lever was ‘indexed’ by virtue of a captive ball bearing clicking into the holes in the drilled washer as illustrated in the drawing by Daniel Rebour below. It was also said that the gear could handle a six speed rear block, making it possibly the first six speed gear.
It appears that the gear was available from about 1950 to 1956. Despite the theoretically sophisticated and revolutionary design, it is rarely seen fitted to bicycles of the period. You can see one on a Herse dating from 1950 on pages 156/7 of Jan Heine’s book on René Herse, and also to my Goëland below. So why was it not a great success? I can only assume that in practice it perhaps didn’t live up to expectations. At present I am having difficulty getting enough chain tension on my one!
Do any readers have recollections of this gear and can they perhaps can shed some light on its shortcomings?
Photo’s of NOS Spirax gear reproduced with the kind permission of Chris Protopapas.
Lefol is a familiar name in the manufacture of mudguards or fenders, particularly for their Martelé (hammered type) and Le Paon (Zeppelin type) versions. But here are two lesser known makes of mudguard fitted to quality French touring bicycles… RBN and Mavic. RBN is the brand name of Robineau, based in Paris at least from the 1930’s until the 1950’s. They made mudguards under the model names of Durex, Alrex and Mangalium, and also chain guards. Pictured here are three different versions of the Durex type – the earlier ones fitted to a 1938 Barra have a rather nice scalloped decoration and a very simple script ‘RBN’, whilst the later version fitted to a Pitard, date from the late 40’s or early 50’s and have the more familiar RBN decorative trademark stamping in the shape of a tree. Both types are for 650b wheel sizes, and have flattish profiled sides, whilst the last one pictured is half round for 700c, and were fitted as original equipment to a 1953 René Herse. Obviously Durex mudguards offer superior protection! Mavic, of course the maker of very fine wheel rims, also made mudguards with the INAL model name. Here they are pictured as original fittings on a 1948 Alex Singer. Again, they are for 650b and have flattish sides.
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