I've had the 45 - 55 mph shakes forever, better and worse at times. Have had my tires balanced 3x times in the past few months with no effect. Just had my tires/wheels (lug centric) balanced on a 9700 Hunter with Roadforce and put plastic hub rings in and the ride is smooth as silk now. I think the X factors were the Roadforce and the plastic hub rings. Now there is 0 vibration at all speeds!