Okay, from what I'm getting so far, it could be a component issue - but it would seem very odd to me that it would be the same with two different bikes and components!

The other is what Dahon.Steve said - maybe a cable issue, though again the same thing on two bikes seems odd. As for a new cassette on the Volpe, I only rode it for a total of about 7000 miles and the problem didn't just start near the end, so I wouldn't think it would be worn out.

The Felt I ride now has just passed 10,000 miles. It had a major tune-up at the end of the first year so I've gone about 3000 miles since then. Don't know if any cables were replaced/adjusted or what.

But I was wondering, considering the crazy stuff it started doing yesterday, if something had suddenly happened to the cable. I'm not mechanically inclined at all to figure that out.