This was done as an exercise for the "modeling with modifiers" course here in CG Cookie.
The sketchfab link makes the rim too reflective, but the original idea was this brushed darkened look that can be seen on this Blender Rendering.
Sketchfab link: https://skfb.ly/HOOP
Thanks for the feedback! I've been working on an improved version where the treads are more prominent. Haven't gotten it to look good still, but working on it!
Nice spokes, well done! The tread could be a little more defined but overall great job!