I missed the thread - but I think the pattern of the crank (ring attaches at base of arm) goes back nearly 100 years - before the lightweights.
I hope this is relevant???
Mike Kone late at night in Boulder Colorado
> Following the thread last week on early alloy cranks, I was surprised to see
> that the TA pattern came into being so recently. I would have thought it to
> date back at least another 10 years prior to it's actual intro date. Along
> those lines, I recently purchased an early cottered aluminum crank from
> Hilary that I would like to know more about. Everything about it says
> 1950's, which would put it ahead of the TA pattern.
>
> Can anybody shed some light on this early French aluminum crank??
>
> http://f2.pg.photos.yahoo.com/
>
> Bryant Bainbridge
> Portland, Orygun