5 Days Ago
I like the idea is a sleeve that would fit over and pin to the axle allowing wide or dual wheels.
You know people would start overloading it.
Replacement wheels/tires are approaching $100/EA, shipped.
I think a single, wide pneumatic might work, but would wooden the width, lessening access, but stabilizing a wider load. There are bakery extensions built for this wider load, already.
It would need matching height tires, or need the axle lifted.
Maybe a simple approach would be a clamp-on tube steel axle that would mount on the underside of the axle, adjusting the height to the wheels. I see lots of 10" and 13" low speed tires.