At 8:34 AM -0400 6/1/08, Via Bicycle wrote:
>amir,
>chuck schmidts campy timeline states that the campy raised pedal
>cranks were used from 1958-1962.
>
>http://velo-retro.com/
>
>Not sure why they were eliminated, but it must have been campy felt
>they were unnecessary. I have always felt the campy crank arm design
>was modeled after all the steel cottered cranks at the time, FB,
>Magistroni,etc, and they all has raised pedal sections. they probably
>felt after seeing them in use, that it was overdesigned in aluminum.
>These are all conjectures, of course. I don't know if anyone as a
>definitive answer now days.
>
>I have never seen an raised pedal cranks crack at the pedal section, I
>do have at least one 1st version crank cracked at the BB taper.
>Williams of England also had a raised pedal cranks, looks a lot like
>the 1st version Campy crank, even uses 151bcd.
>
>joel ralph flood
>philadelphia, pa
In the literature of the time (my source is Le Cycle), it was stated that Campagnolo re-designed their cranks in 1962 to reduce the tread (Q factor) in response to racers' demands. (Look at the archives to see the discussion of steel vs. aluminum cranks and tread/Q factor.)
I suspect that the raised pedal reinforcement was eliminated to reduce the width of the cranks further.
Coincidentally, a number of Campagnolo cranks broke in the 1962 Tour de France. At the time, this was attributed to a wrong alloy being delivered by a supplier, but the author of the article (I believe it was the head mechanic of the Tour) also suggested making the cranks a tad thicker, half-way between the old pre-1962 and the new cross-section.
Here is the original source text:
"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 (tread/Q factor), 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
Editor
Bicycle Quarterly
140 Lakeside Ave #C
Seattle WA 98122
http://www.bikequarterly.com