fat tires and rims?

[Espeefan]

All Tamiya semi-truck and trailer axles use rims that have a hex.

Tamiya's wide rims for the trailers is part number 19335405.
The wide tires are part number 19808176.

They come in a pack of two.

I'm curious why you don't like running the duals though.....given the choice, I'd rather have the duals then a single narrow, or standard tire. Dauls or the wide singles are probably about equal for floation.