Alan Campbell wrote:

I had thought about a car fan belt, reversed so the toothed part is
facing outwards, cut to size and glued to the wheel. What kind of
glue ?

Nothing will hold that on for long.


Anyone have any other ideas on how to add more grip to the wheel ?

Replace both the rear wheels with ones with tread on them? Mose
sheds sell a selection of solid rubber and pneumatic wheels.

--
Grunff