[Al Skierkiewicz]

Gary,
What Dillon is hinting at is a method to take some of the strain off the bearings that will be stressed during side loads encountered on the robot frame. With the bearings at the top of a long lever arm, the side loads on the frame will cause some significant friction to build in the bearings. That friction will result in in the need for significant turning forces. Additionally, a bearing surface near the floor will prevent those side forces from bending the assembly and causing the wheel to ride on an edge, thereby loosing friction with the floor.