Following criticism of my first attempt, I've remodelled, tweaked and corrected several parts of this wheel to produce a much better result.
It now has a hub (and a valve for good measure) and the spokes are more realistically attached. The brake disc is now correctly sited outside of the spokes :-D Finally, the tyre treads are no longer just aligned dots.
Thanks :-)
https://cgcookie.com/exercise-submission/mountain-bike-wheel-attempt-2/
"They" complained about my first attempt because it didn't have a good enough hub :-D So I had a second go.
:-D
This is slick. I'd love to see this in sketchfab.