I agree with scotty and scooterbob, it sounds like the grooved pavement in this case. I get the same problem with my other bikes on the roads that have it. On much heavier bikes to. It's that finely, straight line textured concrete on highways, that sucks. I think they do it so water drains better on hilly highway sections, to prevent icing. Like scotty said, the obvious test would be on flat black top. Also prof mentioned his tire pressure was a little above the recommended setting, how much?