Some more food for thought:
I originally thought "no big deal, this won't affect us because we have a large chunk of glassliner." However I was surprised to find out that the wheels wear a
noticeable and significant amount even if they spend their entire life on the "regolith".
We've got wheels that have never been driven on anything but a regulation surface, and I'm worried an inspector would dub them "illegal".
Since these wheels were made of delrin I foolishly assumed we would NOT need to replace them. ("Durr... how much could they wear down!? This year we don't need to worry about changing treads!") Maybe we need to tweak our drive a little bit to allow for easier swaps...
-John