The 5.75in wheel for my bbq grill broke off. The rest is fine. I finally got frustrated enough to program an OpenSCAD version of the wheel. Most of it is parameterized (outer radius, inner radius, spoke count, indent count, tread count, etc).
I included the version for my bbq grill. I'm printing a matching pair.
This has many other applications. I didn't mean to re-invent the wheel, but I guess it was bound to happen.
[UPDATE] 9/4/2018 - Added insert for bearing and such. I also added variables for sides of things (cylinders mainly).