[Madmiles442]

I've had the same vibration between 65-75. All the balancing in the world did only some good for 2-3 weeks. Very frustrating.
Several threads on this site and others mention the problem being wheels being out-of-round. Others say it's an SPF chronic problem in the steering linkage. I replaced all my wheels ($ ka-ching! $) and almost all of it went away. Not the most cost effective solution, but worked for me.