I used an exercise band to form a new grip for the wheels. A skateboard with a ten pound weight was rolled down a track and into a rig holding the wheel to test the performance in a side-impact situation. Roughtop conveyer belt tread was also tested, and performed slightly better then the original wheels but not as well as my new design.
![](https://i.ytimg.com/vi/yYecQBdA8X0/mqdefault.jpg)