I can't believe it's not the tire,... but you say it has been changed, even the wheel was swapped. Hmmmm, Do you think the dealer would let you test ride another Thrux from the showroom floor? Especially the unit they borrowed the front wheel from. Just so you can see how it feels. Of all the posts about symptoms like this, (there haven't been many) you're the only one that it hasn't been solved for. I know that is of little consequence at this point.
My bike when new, tracked perfectly at all speeds. Now, with a 75% worn out front tire, if I let go of the bars there is a shake between 80 & 90 kph (approx 45 to 55 mph). Above, and below that speed it tracks perfectly. The cupping is now visable and you can feel it by running your hand over the tire.
Don't give up. You're probably more frustrated with the dealer than the bike. These are great machines. Hang in there. This could end up being something simple. The idea about the fork being low on oil is a good place to start.
When I read the line about "shaking like a paint mixer" I thought it was another Harley bashing thread.
