Thanks Ken, that's the best explanation I've heard yet
Mark Bulgier Seattle, Wa USA
Ken Toda writes:
>
> << http://bulgier.net/
>
> Hi, Mark and members who are Campy collector.
>
> It is interesting to study this OLD cranks. What I know are;
> 1958-59 has "caps" Then, 59-60 has no cap but does have extra
> groove beside screw thread of the pedal hole. And still "space"
> under the spider arms. The arm is relatively "narrow" and there
> is no "raised" enforcement at crank shaft hole (it is flat at
> back of spider arm).
>
> Then, Campy probably redesigned the shape of crank arm in 60 to
> 61(?), my guess, the wider no more raised hole for road cranks,
> but kept the "raised hole" for PISTA units.
>
> I know another person has raised Pista 151 BCD crankset, I and
> him studied and discussed about this matter, and we agree that
> PISTA unit was conservative and had to take such load from sprint,
> so there were the raised holes till possible till mid 60's(????).
>
> I remember, even in early 70's, some track racer were using
> 151 BCD with 1/8" chain wheel. There was no need of using
> smaller rings as 44T for fixed gear!
>
> Again these are mostly my GUESS works, I would like list
> member to come up more real historical "facts" in this matter.