Well, the easy way is to hold a Campy 144 ring against the pista cranks and see if the holes line up. If you don't have a 144 ring handy, there is another simple way to tell, if you at least have photos of 144 BCD Campy cranks. The Campy 144 BCD cranks had essentially the same spider as the 151 cranks, at least from the center to the lip that supports the inside of the ring. The difference was in where the holes were drilled in the spider. The 151 holes were drilled further out, so there is a pretty large gap between the inner edge of the ring and the bolt holes. 144 cranks were drilled closer in, so there is relatively little gap between the inner edge of the ring and the bolt holes.
Regards,
Jerry Moos Big Spring, TX
Andrew Gura <agura@earthlink.net> wrote:
i'm wondering how i tell what BCD my campy pista cranks are -- they're the stock equipment on my 74 paramount.
is there a definitive guide somewhere?
i tried the sheldown brown method (http://www.sheldonbrown.com/gloss_bo-z.html) and my chainring bolts seem to measure just below 90mm c-t-c but that would make them 151BCD and i think the bike is too new for that. or maybe i'm wrong.
thank you
andrew gura
silver lake, ca