Anyone know what the Z on a Campy 68-SS-120 BB spindle was supposed to indicate? I have seen it on spindles for both thin and thick, rifled cups dating back to the early '70s, so it doesn't have anything to do with the CPSC mandated changes in '78. I notice that the crankarm does not go quite as far onto a "Z" spindle that I have, vs the same spindle without the Z, though this could be just due to manufacturing tolerances. It doesn't seem to have anything to do with length, flange spacing or offset. Can't be absolutely sure if I've seen it on a triple spindle, but I believe I have.
I cannot find anything on this in the archives or usual places.
Steve Barner, Bolton, Vermont