[Jeff Waegelin]

We used four 6" AndyMark plastic omniwheels (like those in Andrew Schuetze's picture). We only had one break, on our practice robot right before Nationals. We were in a heated battle with 469's practice robot at their field, and we got jammed up against the ramp and broke off one roller. Other than that, they worked great. A perfect balance of price and performance, IMO.

On a side note, in my experience, 6" wheels have usually been the "sweet spot" for most games that didn't involve large variations in terrain. They usually seem to be about the right balance of speed and power, without requiring excessive gear reduction. Also, I've used bigger wheels before, and they tend to take up too much space, and can sometimes make for awkward turning. They're great for games with ramps and stairs, but for a flat-field game, I always choose 6".