I'm pretty sure the Dunlop 491 on mine is a 140/90B15. With stock shocks, it would not rub without the saddlebag supports installed. With them installed, it was necessary to raise the shocks to their highest position and replace the original mounting bolts for the side rails and saddlebag supports with some mushroom head hex bolts that look like this.
That alleviated the rubbing. Mine is a '98 so I don't know what other mounting changes may have occurred with the differences in sissy bars and such between the two model years.
I later installed 12.5" Progressive shocks, replaced the mounting bolts with the normal ones, and have never had any issues at all. I think I've read of others using 11.5" or 12" Progressives to alleviate the problem too.