On wheel balancing the above referenced article states:
Dynamic balance, on the other hand, means the equality of weight distribution between the two sides or planes of the wheel/tire assembly. To put it another way, if you view the tire from the front and split it down the middle with an imaginary line, the weight of the left side should be the same as that of the right side.
If not, the heavy spot in one plane will be pulled toward the center by centrifugal force as the tire spins, causing vibration or shimmy. The action here is usually more subtle than that of static imbalance, but it can still drive you crazy. It's more critical, by the way, the wider a tire is -- you won't find this problem on bicycles.
It takes pretty sophisticated equipment to eliminate dynamic imbalance. If you've only got access to a bubble or gravity type static balancer, the best you can do is to be sure not to cause dynamic problems. That means you'd better split the weights and mount half on the inside and half on the outside of the rim.
I don't think I have ever seen my tires balanced that way. Unless the local shop's spinning balancer does more than it looks to my eyes. I also generally have never seen them put weight on both the inside and outside. It has been an either or thing. I could be wrong.
