Originally Posted by
dvizz
I have two wheelsets. One with a Campagnolo Chorus 11-29 on a Campagnolo Zonda and a Chorus 11-32 on a Bora Ultra. I like to swap the wheelsets out to keep the Boras from getting gritty winter usage. When I install the Zondas the chain will hesitate dropping down to the middle cassette rings whereas on the Bora cassette all the down shifts are smooth. I loosen the cable knurled knob a half a turn and that remedies the hesitation. I'm wondering why the cassettes have this bias, I checked the spacers between the cassette sections and they are per spec.
the problem isn’t the cassettes - it’s the hubs. Ideally, all Campag hubs would be seamlessly interchangeable, but this isn’t always the case. In your case, it seems like the Zonda hub is placing the cassette slightly “outboard” compared to the Bora hub, so you’re having to slacken off the RD cable a smidge (ie moving the RD out a bit) to bring the Bora-adjusted shifting in line with the Zonda-located cassette. A spacer behind the Bora cassette would solve the issue by placing both cassettes in an identical position wrt the RD. The actual thickness of the spacer is a matter of trial and error, but once you’ve nailed it down, adjusting the shifting for one hub will translate perfectly to the other hub. Use that spacer every time you install a cassette on the Bora and you should be able to swap between the Bora and Zonda without having to adjust anything.