Thanks for the suggestions guys. I'd like to know exactly what 28 oz. imbalance means. An extra weight located towards the O.D. has more effect on balance than the same weight in the middle. Maybe the automotive engineers have an 'understanding" on this and use the terms "28 oz." and "50 oz." to simplify the nomenclature. From doing a little work with gears, I've learned about a term called "diametral pitch". It's basically the spacing between adjacent gear teeth. Whenever two gears mesh, they must have the same diametral pitch so each tooth on one goes into the gap between teeth of the other. A designer can take the diametral pitch number and the number of teeth he needs on each gear for the reduction ratio to get the pitch diameter of each gear and the center spacing.
