I started trial runs of my yard robot last weekend. One of the problems I had was traction in the grass. I'm using the 8" dia pneumatic wheels from Harbor Freight. They're salmon-colored, non-marring, ribbed tread. Heckofa deal at $4 ea, but not great in grass. What I really need is 8" dia knobby pneumatic wheels. HF only has the knobby wheels in 10" dia.
Anybody have a good source for these? I specifically want 8" knobbies (the squarish blocked tread). They grip grass very well.