The steel rims that I have are actually two pieces, one piece is the round metal rim and the other piece is the center section.  I think that the problem is caused because the center section wasn't welded on very straight.  They do wobble a lot, but I have had no vibration problems on the highway.
 WELL HOW ELSE WOULD YOU KNOW IF THE WHEELS WERE MESSED UP :-/ ...IF YOU DIDN'T USE THEM......SOUNDS LIKE SUMMITT NEEDS A LITTLE BETTER CUSTOMER RELATIONS
...CAUSE ITS STORIES YOU HERE LIKE THIS THAT MAY MAKE YOU CHOOSE A COMPETITIVE VENDOR
...WHEN 2 SEEM TO BE EQUALLY A GOOD DEAL ...IT THEN GOES TO WHAT YOU'VE HEARD OF VENDORS IN QUESTION.........SOUNDS LIKE POOR SERVICE SUMMIT ÂÂ
Thats what I told Summit..

 Who the #$%^ would ever check to see if a wheel was true or not before mounting a tire.

 Well, they did offer to take a look at them, but only if I could clean them up and make them look brand new.  Also, they said that if they did not find any problems with them they would send them back with the shipping at my cost.  Thats crazy because then the shipping would end up costing more then the rims themselves.