Robot Dimensions/Perimeter

When it comes to robot dimensions is it correct to say that the max perimeter is 120 inches before bumpers? Do the bumpers fit within the perimeter extension of 15 inches?

Yes. The bumpers are included in the 15" outside of frame perimeter, so you really only have 15-3.5= 11.5" if you want to go over the bumpers for an intake or something