Hard to imagine that anyone would have all the dimensions of a Campy RD mounting bolt memorized, but the general guidance is that if the bolt wasn't purpose made to work with a Campy RD, then the chances of it working "just by chance" seem pretty slim. Do you know whether this bolt is supposed to work? Both the location of the groove for the circlip and the width of the shoulder on the head would have to be right for this to be interchangeable.SDizzle said:Take a look at the picture. Anyone know off the top of his head if this will fit a Chorus rear derailleur? I'm too lazy/busy to take mine apart right now... Thanks - S.