Hi sorry to hear about this problem, don't understand why it is happening, but there are two things you should have checked before anything else. the wheel balance and the front wheel bearings. I have had a similar problem with my nightrain when it was new.
I also have a 2010 Street Glide very stabe all the way up to max speed, althogh a crosswind can give a little problem.
Normal riding speed at around 110 can run hands off, through sweepers like on rails.
are you in sydney