I have the same vibration at 65 to 70. Changed tires from Yokos to Nittos, 4 wheel alignment, road forced balanced on a friends Hunter 9700 putting weights on the inside and outside of rim. I have 17" rims and have tried
a set of 15" with Goodyears from a friends car that does not have the vibration and mine still had it. The vibration was much less with the weights added to the outside but is still there right at cruising speed. There has to be a solution somewhere.
