I have a nearly new 2004 450F just replaced rear tire at friends house who has all the tools including tire mounting and balancing equipment. Tire was balanced and put back on. As soon I rode down the street I could tell something was out of whack. Tire shimmy's very bad, everything looks ok, my buddy says he has never seen anything like it. does anyone have similar experience and tips to get this working properly? I got it figured out, my buddy said to me: you have some loose spokes, he tightened spokes that had a different ping sound than the others, found out he must have adjusted one side to much, causing the rim to wobble. I am having the spokes retuned/tightened by a repair shop, hope that does it.