>In the hopes of advancing the dialogue on dating the Stronglight 49D
>crank through it's unparalleled history I've uploaded a collection of
>photos that will hopefully illustrate most if not all of the general
>variants that can be seen and perhaps referenced to provide examples
>useful to this end.
>
>http://picasaweb.google.com/haxixe/Stronglight49D#
>
None of the cranks on your list appear to be pre-war, from my quick glance. Compare to the LEFT crank of the bike in the auction. (The right crank is a post-war model - I just noticed that now.)
ebay 370196769044
>The 49D is to me the ultimate single component spanning the on-topic
>era of the CR list. In terms of longevity, performance and utility, I
>can think of nothing that comes even remotely close. First built in
>the 1930s and still almost fully competitive with the most advanced
>current gear. If you told the people that built the first example that
>their design wouldn't be significantly bettered in the following 70
>years, I wonder what they'd have thought?
That is a good question. Who were the engineers? How did they manage to get it so right, on the first try? There is one other product that compares, but never had the success of the Stronglight: the Nivex rear derailleur. The first ads from 1938 or so talk about constant chain gap as a key toward consistent shifting. That reads like something straight out of Berto's "Dancing Chain" in the chapter "How to design a well-shifting derailleur." Other makers took decades to figure this out, and Campagnolo's early Syncro shifting would not have been doomed if they had understood this in the 1980s.
Jan Heine
Editor
Bicycle Quarterly
140 Lakeside Ave #C
Seattle WA 98122
http://www.vintagebicyclepress.com