Did you balance the tires? A 650 would have no problem keeping up to highway speeds and the last thing you need is high speed wobble. Most M/C shops just use stick on weights.
There's a perfect project for you! Build a motorcycle stand like used for motocross bikes. Make it so it holds the bike a few inches off the ground. Then it's real easy to change tires and adjust and oil the chain. Also good if you need to work on the suspension or take things apart. Put a hole in the middle of the top for changing oil.