I think part of the issue is that you are not seeing the whole picture.
The robot has two of the system you are looking at at a 90 degree angle to eachother with the wheels coming together in a V-shape. The bottom of the v is where the pole is of the corner of the pyramid hopefully will be. It is our hope that as the robot drives up the pole the wheels will sort of grip the pole. with the original design the triwheels were meant to rotate around the cross beams. We realized shortly after we selected this design that the triwheels would bind up as soon as they came to an obstacle and tried to rotate because the arm length is longer when the wheels rotate down then when the wheels are flat. So...we came up with the idea of having the wheels on articulating arms so that they can move up and out allowing them to rotate around. In this way we hope to drive over the cross beams and have the wheels rotate around them.
It is our hope that articulating the wheels will also allow the wheels to drive over the cross beams without tilting the robot over backwards.
Fingers crossed. :-)
Hope this helps clear things up a bit.
Edoga