It's time to replace the chain/cassette on my Campy 9-speed, but I can't find a Campy 9-speed 12-25 cassette. (Probably a sign that I should upgrade the whole gruppo, but not this year.) I've got 39/53 chainrings and have always assumed 12-25 was the way to go in the back, though I honestly haven't experimented with other cassettes. So my choices seem to be:
Miche 12-25 cassette (I'd rather stick to Campy but...)
Campy 12-23 or 13-26
I'm also considering buying a 10-speed cassette, dropping one of the cogs, and using my 9-sp spacers -- will that work? There are plenty of 10-speed cassettes to choose from.