[Pat Fairbank]

Sorry for not replying sooner - I've been at robotics all weekend until now.

Those wheels weigh ten pounds each, and we are using two in the front, with two six-inch wheels in the back.

We actually designed the sides of the plates that way (not straight) , only because we found that the metal would touch the corner of the step while we were climbing it. It's not a curve, just either two or three seperate straight sides that meet to form corners. We got the plates, shafts and wheel hubs machined professionally (I'm not sure what method they used, but the plates look pretty sweet up close).

The turning is very good, considering all eight of our wheels are made of neoprene rubber.

Hope that answers all your questions.