A 6” diameter wheel has a load capacity of 2,000 lbs. 8” wheels can support 2,500 lbs., 10” wheels can support 2,900 lbs., and 12” wheels can support 3,500 lbs. While you may be only looking for wheels with load capacities of 75 or 100 lbs. each, the principle remains the same –Perfectr diameter wheels can support heavier loads.