I have 2 of the 1 hp Rikon grinders, purchased maybe 2 years apart. The first one, the wheels were so out of balance that I wouldn't have given them to some one I didn't like. Very cheap plastic bushings, which added to the problem. They had about 1/8 inch (+/- 1/16 inch) of side ways wobble in them. The second one I got, if I didn't have CBN wheels, the wheels that came with it were far more true, and it would have been possible to have trued them up.
You can true your wheels with one of the T wheel dressers. You need a good platform. Then, you ease the dresser into the wheel just until you can feel it contacting the wheel, but with very light pressure. What you are attempting to do is nibble off the high spots. Wheels generally need dressing on both sides and the face. I true up the sides first, and then move to the face. With the first set of wheels on my first grinder, they were so bad, it would not have been worth the effort. With the second set, i could have done it. You could save yourself the work of ever having to do that again by buying CBN wheels. I consider them to be like variable speed on lathes. Once you try them, you never go back...
Spin your wheels by hand to see just how bad they are. If your grinder is dancing around on your bench, some thing is way off....
robo hippy