I have a new Orbea Diva with Campy Chorus group components (purchased last August). About a month ago, I began to have problems with the chain staying stuck on the large chain ring up front, and also with "ghosting", or slipping between, the front chain rings. My mechanic had the same problem when he test rode it, so we sent the crankset back to Campy (minus the chain . . . they didn't want us to send it). They tested it and rode it for 40 miles, on one of their bikes. They then sent it back and said there was nothing wrong with it. My mechanic then put on a SRAM chain, which is 2mm wider than the Campy chain, and now it doesn't ghost or stick, but I'm having lots of chain rubbing, despite a derrailer adjustment. Any advice out there?