I had the same thing happen to me. Right at 100 mph the front would shake bad. I checked the wheel and tire for round and couldn’t find a problem anywhere. I put on a new front tire and all was fixed. The tire was a Metzler 880, wore but not wore out. A few days before, I had hit a cut in the pavement where Penn DOT was doing something. It was a pretty hard hit so I figered that caused the shake even though I couldn’t see anything wrong. Dealer tightened the head bearings and checked the balance with no help. In the end a new tire fixed it.
