Urethane wheels, PVC hubs and those cheap unsealed ABEC none bearings. The flat skate bearings just need that .250 spacer to allow the nuts to cinch down on the solid metal collar the spacer and the 2 inner races create and let the wheel spin freely. Without a spacer the nuts lock up the bearings. With the cheap bearings the wheels seem loose on the shaft but the nut is tight. Loads of play in those bearings. My kids cheap *** Roller Derby skates had better bearings but I can only find 1, I saved it to make a roller for rims when im polishing them on the bench. Side note: my mom's small town in north east Texas used to get a portable roller rink for the summer season. It was about 1/2 the size of an Olympic swimming pool, raised 3 feet off the ground and made with a bunch of 1" plywood sheets on a metal frame. They set it up with carnival tent over it (open sides cause its 106F in Texas in July) in its own lot off the main drag. Uneven as heck, it was pretty hard to skate on it but was better than nothing I guess.
