Wheels are heavy duty, polyurethane, Ø4†x 1 1/4″ wide with two sealed roller ball bearings per wheel. Support wheels are on a maximum of 8†centers.
Wheel fastening shoulder bolts are Ø5/8†with 1/2-13 threads. (Some competing units use smaller than Ø2†x 9/16†wide wheels with 7/16†hardware.)