My neighbors are doctors, and they had a couple anesthesia machines that they intended to leave out for scrap. I thought the wheels on them might make perfect dollies for my new-to-me Porsche wheels and tires.
The equipment was heavier than I expected, which was good, because those wheels really seemed to be built for the task. They also rolled really easily across asphalt, all the way from my neighbor's driveway to mine.
It took me a while to figure out how it was put together, but once I had one of them taken apart, I found that four nuts and a single cut of a metal brace would free my wheels from the whole apparatus:
I cut out some scrap plywood into circles to distribute the load on the tire. I wouldn't want to damage the sidewalls by storing them stacked four-high on four square inches of surface.
They roll around so nicely in my garage and driveway now. Way better than any Harbor Freight piece of crap could. I'm pretty happy with this little project. Eventually I'll attach the plywood to the cast aluminum frames with four carriage bolts, but for now they just sit on top. Which is what they do most of the time anyway!