I think I read about this here in the past, but here's my version.
I found 10 in. pneumatic tires/wheels for $4.50 ea. at Harbor Freight (300 pound capacity per tire, ball bearing hub), new 5/8 in. axle
at the hardware store for about $4, and a couple hitch pins. Axle
spacers out of 3/4 in. CPVC.
The wheels have a bit of a hub which I mounted outboard to enable insertion of the hitch pins. I could have used cotter pins and flipped the wheels around to narrow the overall width but I wanted to be able to easily remove the wheels altogether.
Filled it with water and pulled it around the rough patch I call a back yard (Look Mildred, that crazy neighbor is running around, pulling a blue thingy in his yard!) It pulls real easy. A wide track for nimble handling! Knobby tires
for all terrain traction! I'm sure they're low rolling resistance tires
for improved fuel economy!
Racing stripes next? Maybe flames would be more appropriate, tho'.