Greg Parker enthused:
> Note also the one shown right below that:
> "Campy Pista crank with 144-bcd and 151-bcd"
> Now *that's* versatility!
I've made a few of those, once by hand filing, a couple with a milling machine. I don't recommend the hand filing technique unless you're pretty good with a file and quite patient - a little too much off and you've got a sloppy fit, with most likely only one bolt out of five taking all the strain. Any machinist can do 'em on the mill.
Strada is easier than Pista, as Pista needs the counterbore on the backside of the spider. I hardly have to mention you can't do the counterbore with a file, that's for the mill only. Well, maybe Brian could if we dared him to, but no one with only two arms could file that. Pista leaves the head of the nut partly unsupported, possibly a little weaker than the factory setup, but with a road double it's as good as new - and after the rings are mounted it's almost impossible to tell the arms are modified.
You still have the 44-tooth minimum of the 151, but you can get there with far more common 144mm rings. You might could modify the arms a bit more to squeak a 43 in there, I don't know, never tried, but no way on the 42.