Without modding the swingarm more than notch and brace i say 190 is the widest you can go without rubbing on the SA and no offset. Offset is lame work... Better not to do it than offsetting the wheel. That will change all the balance of the bike. Better to cut and weld the SA to make it wider for shaft not to rub the SA... Everything depends on hoe deep you want to go. I made a SA from scratch to fit a 11" rim with a 300 tire. I thought if i have to change it a bit for wider lets do it big time. The only thing is that if you go to 240 or bigger you have not only to change the swingarm for shaft not rubbing but you also have limitations on the U-joints so you have to brake the shaft in 2... The wheel mod is no more than copying the vmax wheel correcting for the offset required to center the wheel on the swingarm. Just get a log of alloy on the lathe and copy the vmax rear wheel hub where the 6 pin contraption that connects to the diff gets fixed and weld it corrected for the offset i talked about. You can do another minor thin that is push the rim to the right on the swing for tire clearance and then push the swing to the left on the frame, the tire will be centered but bare in mind that the shaft will be closer to the inside wall of the SA (the notch). An extended SA will also help because the shaft will be straighter and the wheel will be further aft, in that case an extended shaft will be required. Many options to meet your wishes...