Chuck brought the discussion of steel vs. aluminum cranks from the iBob list to this list. He claims that there is no support for Bicycle Quarterly's assertion that racers in the 1940s and 1950s were concerned about the tread (Q factor) of their cranks.
(Bicycle Quarterly wrote that the wider tread, rather than the (unfounded) fear of breaking cranks, was behind the resistance of professional racers to adopt aluminum cranks, which were introduced in 1933, but only found widespread adoption in the 1950s.)
In Le Cycle July/August 1962, P. Delay, the chief mechanic of the Tour de France, wrote:
"But it is obvious, that because of demands of the racers, who always want to reduce the width of the pedaling [Jan's note: what we call tread/Q factor today), the manufacturer was moved to reduce the thickness of the cranks by 2 mm."
Delay refers to the Campagnolo cranks that were redesigned in 1962 with thinner-section armsn (see full quote below).
I believe that this quote supports BQ's article that tread (Q factor) was considered important among pro racers at the time - note the "_always_ want to reduce the width of the pedaling."
If anybody has a contemporary reference from the 1940s or 1950s that contradicts this, I'd like to hear about it...
Until somebody finds such a reference, everything else is just speculation. Of course, this was discussed here before (check the archives), but it seems that evidence alone isn't enough to convince people to abandon long-held beliefs.
Jan Heine Editor Bicycle Quarterly 140 Lakeside Ave #C Seattle WA 98122 http://www.bikequarterly.com
Years ago, I posted the complete quote:
Archive-URL:
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"In fact, there were some Italian cranks made from light alloy that broke. In my opinion, this is due to the material used in a particular series, no doubt by the subcontractor who supplied the raw forgings, who might have mistakenly used an alloy that is too "dry," and not the one usually used, which until now, had given perfect satisfaction.
Knowing how reputable this brand is, without a doubt the necessary has already been done, but it is very difficult to retrieve a defective series after quality control could not detect this hidden flaw.
Perhaps, if the manufacturer had retained the original cross-section (of the crank arms), this problem would not have occurred.
But it is obvious, that because of demands of the racers, who always want to reduce the width of the pedaling (what we call Q factor today), the manufacturer was moved to reduce the thickness of the cranks by 2 mm. Even though the wise decision was taken to augment the width of the part by the same measure, the reduction was made in the direction of the maximum load, where flex can occur when the pedal is pushed. I think it would be good to return to the original cross-section.
This does not keep us from admiring the precision and finish of the Campagnolo cranks, and also remark the perfect record of the Stronglight cranks and TA rings."
Translation Jan Heine (rough, sorry, no time to polish). Translator's notes in parentheses.
Source: Le Cycle, July/August 1962, p. 33
Jan Heine, Seattle