Just replaced tires on my 2007 400. Got 14,000 miles out of original hoops, so went back with hoops again, both front and back. Took it to a local bike shop for mount and balance. There are weights on the wheel so it appears they did balance. But, now at indicated 80 mph (normal traffic flow), I'm getting a definite vibration up through the seat. The bike has always been super smooth, had it up to indicated 101, with no vibrations. So, tire issue, or something else going on?