[Oblarg]

Do you have enough space to pull those wheels without removing the outer hex frame if you need to do maintenance?

I'm not quite so sure I'd be comfortable with that little substance behind the bumpers on the side. I've seen some crazy deformations of fairly significant framing members through an FRC bumper (I've got a piece of last year's AM14U chassis sitting right next to me that fits the bill). The frame rules are there for a reason - if you take a hefty impact at the least-supported part of your bumper, are you certain it won't fail?

Cool solution for getting the motors out of the way. You lose the benefit of a direct-driven center wheel in the case of chain/belt failure, but that's probably a worthy tradeoff.