To answer the above questions:
A pair of them lasted us through the Chesapeake and Canadian regional events. They were specially designed [by students] for last year's game to both stick very well on the HDPE and to clip onto the steel mesh of the ramp to provide extra traction
The lexan was incredibly strong and the urethane was durable.
That urethane was provided for us by BorgWarner Automotive. Our head engineer brought sample material and we liked that version best. Then our staff of on-call machinists cut it. Have you ever cut urethane? It's about as hard as welding aluminium so we left it up to the pros. Even then it took a week before we got it back.
We may or may not be using omniwheels this year. But if so, then expect something interesting
