when I first rode behind my friend Phil, he on his rocket, me on mine. I noticed he "looked" like he was riding the bike at a tiny angle. We stopped and talked about it. So we switched bikes... same thing. he "looked" like he was a tiny bit down on the right. I didn't feel it on my bike or his bike. We watched each other on both bikes. To him everything seems fine. To me, both bikes looked a tiny bit down on the right.
Now the stupid part. "OF COURSE YOU MORON" I said to myself. you throttle up with your right hand so the angle of the wrist is down in reference to the left and, at least, for both of us, we finally realized, without actively knowing it, sit with a very very slight adjustment to compensate...
TOTALLY NOT related to the above: one other thing happened on my bike. When I first picked it up I could not let go of the handle bars without having to do a more than mild weight shift to keep the bike centered. It wanted to go right. I took
it to the shop, they went over the bike and rebalanced the tires... didn't help.
What did help was moving a bunch of tools and battery tender from the right saddle bag to the left... go figure. sometimes I really am blonde.
so, there might be a number of niggly little things you should look at with a fresh eye.
cheers
geo