Sheldon Brown and I variously wrote:
>
>>Your Rochet, being a production bike, did not offer the gear range
>>you'd find on a top-drawer cyclotouring machine. Most of the
>>equipment was an odd adaptation of racing gear, which you wouldn't
>>find on a well-spec'd Herse, Singer or Routens. A typical Herse
>>triple from the 1950s is 48-40-32.
>
>Yes, but these bikes, I would expect to be equipped with a
>chainstay-mounted Cyclo helical derailer, the kind that used a
>screen door spring, not a self-contained, dropout mounted unit.
Of course, the good bikes featured derailleurs able to shift wide ranges, whether Cyclo (90%), or the less-common Nivex, Huret and Spirax. A true cyclotouring bike wouldn't have used a racing derailleur back then. And the racing derailleur probably is why the gearing had to be limited on your Rochet. A lot of production bike shops tried to turn out "cyclotouring" bikes by adapting racing bike designs. The true "constructeurs" didn't worry too much, as these half-hearted attempts were no competition for their custom-built machines. I am sure they were a lot cheaper, though!
There also were true production cyclotouring bikes, made by RPF
(later CDF) and others. These were as functional as a Singer or
Herse, but didn't feature the same quality or light weight. But then
as now, most cyclists were fascinated by racing, so it was easier to
sell a bike with famous, albeit less suitable components.
>>The 48/30 is not unusual at all for a French cyclotouring bike. On
>>doubles, the big ring usually was 48 or 46, the small one 32 or 30,
>>rarely 28. Still a good choice today. (See the article in VBQ vol.
>>1. No. 1)
>
>That's the only one I ever saw. The (cottered) Rosa crank had a
>large diameter (maybe 2") thread at its base, and the big ring
>threaded onto the crank much as a freewheel threads onto a hub. The
>30 chainring bolted to the 48.
Most bikes after the war used Stronglight 49D alloy arms with TA
rings. Sometimes, you'd find the Duprat hollow steel cranks, or the
cottered Maniplume alloy ones. But the better bikes were 95%
Stronglight, except Herse with his own cranks. The Rosa/Cyclo rings
were cool in the 1930s. By 1960, the steel ones were found on cheaper
bikes only.
>
>I agree that it was a good setup. I found the low pretty adequate,
>but the 48/14 top gear didn't satisfy me so I soon converted it to
>10 speed, later to 30, and at present this bike has a 63-speed rig
>http://sheldonbrown.org/otb.html
You are faster than I am! For me, 48-14 is perfectly adequate for non-racing, even on the tandem with smaller 650B wheels.
Hugo Koblet won the Tour in 1951 with a 50-14 (see the recent issue of VBQ). But he was faster than both of us, I suspect. (Maybe, if Coppi only had had a 50-13, he'd have won...)
In fact, big gears were available even back then: Jo Routens used a 52-13 (6-speed freewheel!) on his tandem in Paris-Brest-Paris 1948! Big gears may be a recent fashion (at least within the CR timeline), but they have been available for a long time.
--
Jan Heine, Seattle
Editor/Publisher
Vintage Bicycle Quarterly
http://www.mindspring.com/