Since I first made my wheels they have constantly evolved until I made the last set using a 75mm aluminum strip as a spacer, pop riveted to the spoke holes of aluminum rims(one side of each rim cut off) I have run the same set of wheels for 3 seasons now with no sign of failure so I think I have finally got it right.
I am now testing another tire that I think will be perfect for harder surfaces and at low cost. Crazy bob 2.35