On Apr 22, 2007, at 1:28 PM, Jan Heine wrote:
> That is why many older frames have indentations in the right
> chainstay to clear the small chainring. If tread was of no concern,
> it would have been easier simply to use a longer BB spindle.
Once again Jan... I never said tread was of no concern!
I said that the small tread difference between a steel crank and an aluminum crank in the early fifties was not why the pros only used aluminum cranks for mountain stages and steel cranks for the rest of the stages in the Tour de France. The reason (my opinion of course) was that they felt that aluminum cranks were not trustworthy enough to use for a 2500 mile plus stage race.
I find your conclusion that difference in tread was the factor, and not the fact that aluminum cranks were unproven in pro racing in the early 1950s, baffling in the extreme. Sorry, once again I have no references or footnotes, only the "fact" that that's what they rode back then, which you yourself have substantiated.
Chuck Schmidt
South Pasadena, CA