You're assuming that this is the complete assembly for climbing. It was mentioned that some small changes in the event of climbing being required are easily doable on this design. One gear change per box, and 6 inch wheel instead of 4 inchers. Or, I could leave one side open and put a roller on the front, much akin the 254 during raising the bar (I think theirs was to stop them from rolling over balls, but a few small mods and it would work for ramp climbing).

EDIT: I never sleep.... I need to stop forum lurking....