We accidentally dropped a KoP wheel off a table onto a concrete floor, landing perfectly upright on the tread. Some tiny chips flew off as it bounced, but the photo shows the ultimate result.
I do not feel this to be any kind of design fault, rather the wheel was badly abused. I am posting this to caution other teams to be extra careful when your wheels are near the edge of a table...
What is fascinating about the break is that the outer rim of the wheel is definitely in some tension, to the point that we cannot force the crack back together by hand. Only one wheel segment is cracked, and I am assuming the other five segments are bending subtly to compensate.
Sorry about the fuzzy photo; cellphones are not excellent cameras.
Don