Unless your sponsor has a break that is less than ~1" tall (min distance between bearing plates) and can extend 4" (height from bellypan to top of tube) into a piece, they cannot bend that piece.
If you make the side "tubes" that the bearings sit in two separate pieces and overlapped them at the top and bottom, it would work. See Robowranglers'
X009 Design Log.
Otherwise, looking pretty good. Just make sure that you leave space to get the sprockets and chain inside that side rail for installation and maintenance (I would make a hole in the belly pan in front of and behind the tube).