So, with the 18" rear wheel and the Kawi front sprocket, the swingarm cross brace has to be chopped a lot. Kinda worried about how little metal would be left behind, and how flexi the S/A will become. Also worried about how much the whole gag will warp and distort between all the chopping and adding and welding.
So, I figured I'd start by wiping off all the stuff I don't need. Not running a belt guard. Going to use a rod for the rear brake instead of a cable, and so on. So, 4 1/2" grinder, Zip Cut wheels, sanding pads, lots of sparks, lots of dust.
Then I got a piece of rectangular tubing. Coped the ends to fit in the swingarm. Got some lengths of threaded rod (1/2" and 5/8"). Ran the threaded rod through the swingarm pivots, the axle slots, and the shock mounts. Double nutted them all. Figured that'd hold things a bit.
Fit the brace in, and tacked it up. Production welded the top and bottom and let it cool. Figure the two horizontal welds will cause the least distortion. Once it cools down. I'll loosen the S/A threaded gag and preload the nuts against the inside faces of the S/A. The vertical welds are going to want to pull the arms together, so if I have them spread a bit, it should average out.
If it is too wide, I'll just tighten the S/A pivot nut a bit more. If it's too tight, I'll put the threaded rod in there and tighten the nuts against the inner faces of the S/A and spread them out.
For now, it all stays bolted together until I chop out a lot of the existing brace, make a plate to cover the new hole, and weld it all up.
Somewhere in that all, I'll elongate the axle slot toward the front so I can get the belt on without a fight.
Just bolts on!
-Armen

Nice work!

Suzuki & Kawasaki both well known for long flimsy swing arms. Ryca did my S/A. I plan on doing my own with a full length web on the underside.
I did chain conversion so my left shock was waay out in left field so made new lower mount , lower left shock is directly over S/A and shortened top mount too, looks much better, bike handles nice. S/A doesn't need replaced just want to do my own to brush up my fab & welding skills, ya know a fun project !

I was very surprised how well mine handles with just the progressive shocks & springs, but if I had to redo it I would do the S/A thing and derake the steering head a bit . I get a little push when going into turns too hot, but overall for a cruiser frame with no center supports it handles very quick & light , very nimble. Don't think it will hold up well coming down hard from wheelies, it will break somewhere from those kind of forces. Light frame & heavy engine something gonna give!

Oh no , no need to cut it off , way too much work & then it all needs to be aligned
Some angle iron , all thread & nuts,drill,wire welder and my personal favorite tool a Saws All
Adding rake cut from top
Derake cut from bottom
Your skills much more advanced than mine I'm not even going to try to tell you how
Love that tank/seat looks wicked,looks much faster than a Ryca combo
Shapes & lines, must pay attention to shapes & lines !

Armen , Is that a Laguna Seca track map on the wall behind you bike ?

The tank and seat are aluminum, Indian made copies of a Benelli Mojave.
Gotta say, pretty nice work for the price.
Just have to do all the mounting stuff and make a sub pan for the seat  

JOG , Only you would waste Viagra in such a manner