It's happened twice now. Traveling in a straight line at approx. 75 mph and bounce over a bit of crappy pavement. Rapid handle bar shake - four or five osculations. It settles down on its own, but the sphincter factor is a high five. I've been riding sport bikes for forty years, and have had my share of tank slappers, but not in a straight line, and not without asking for it. Anybody else out there experienced this?