The loose nut behind the bars can sometimes be an issue.The tires are good with proper pressure. They are the Dunlops but the bead is good. My girlfriends friend, the lead mechanic at a Harley shop said told her exactly what I wrote here without her telling him.
He said probably bearings or loose nut in the triple tree and that its usually worse during decel which hit the nail on the head. I'll check it tomorrow and keep you guys posted. I'll also get that manual downloaded