Originally Posted by
genejockey
The fact that it's only a problem on one bike and not the other obviously screams "Fit Issue". I'm curious what, though.
Well, it was brought about by time on the trainer and that's the only bike of the two that's seen significant time on the trainer, IIRC; he's got several thousand trouble-free outdoor miles on that same bike. Trainers are a great litmus test for fit, and there's no guarantee that putting the Madone on the trainer would be happy good times, though that might be something worth trying after a bit of time off.