Luckily (actually, some planning for a change) the swing-arm I'm using has parallel sections exactly 1" X 2" X .090"(? with paint), I'm going to patch in some 11 gauge (.110").
I assume it's good practice to close up the "nose" of the open area to about the same safe distance to the tire as stock (i.e., add 12", close off empty forward area by 12") to improve rigidity? Tire is about same OD as stock.
I'm going to retain the suspension - if my engineering/fabrication skills are up to it!
I see the small cross-section arms (like mine, as opposed to 'Busa, R1, etc.) generally have some bracing added both along the top or bottom and also in 3rd dimension above or below at the pivot.
Other than clearance to some part of the bike or surface, isn't a bottom brace stronger for the same amount of metal? IMHO if the welds are good a tube will be stiffer in tension (on the bottom, being stretched up) than compression (on the top, being "folded" in compression). Am I overlooking something?