Amir,
Apart from a 4-speed Cyclo Standard rear derailleur, various Simplex models were available to take 14-28 teeth. My early-mid 50's W P Newton (the one which I bought from Doug Smith last year, and which is illustrated on the British Main section of the CR website) has its original Simplex long-arm deraileur, which I believe to be the Grand Tourisme model from the early 50's - but I'm open to correction on that.
The double chainwheel is a contemporary steel 5-pin Simplex, in 44/28 teeth on BSA cranks, and this, with a 4-speed block with a 28 tooth bottom gear sprocket, gives me a low of 27 inches. You could also use Cyclo double chainwheels in touring ratios, which you might be able to find from a French source.
I've never come across the Simplex chainrings, apart from the ones on my Newton, and I'm getting pretty desperate to replace them, since after 50-plus years, they're getting very worn!
Neil Foddering
Weymouth, Dorset, England
>From: Amir Avitzur <avitzur@013.net>
>To: Classicrendezvous <classicrendezvous@bikelist.org>
>Subject: [CR]Drive-train for mid-50's Hobbs ???
>Date: Fri, 07 Jul 2006 09:37:20 +0200
>
>
>I'm kind of partial to run-of-the mill road bikes.
>They don't demand the care and maintenance of beauty queens,
>and I don't feel guilty about abusing them on dirt roads and such.
>
>So when my Hobbs arrived, I was thrilled.
>Its not their best model, but its well built and sturdy.
>Plus my wife likes the color.
>
>As I can only have one road bike in the house at a time,
>the Hobbs frame has got to be turned into an all-purpose bike.
>For me that means a wide gear range
> in the neighborhood of 52/36 ... 14/28.
>
>Were there any rear derailleurs in the 50's that could handle that range?
>
>In the 50's, what double cranks besides the 49D could handle ~36 teeth.
>
>
>Amir Avitzur
>Ramat-Gan, Israel