Eh, let 'em touch. I've got a fully inflated 265/70R17 jammed under mine and it's squeezed between the sway bar and the hitch but it fits. That part of the bar doesn't sway, it sort of twists from the middle out, so there isn't much rubbing contact, and the tire should be cranked down so it won't wiggle. 30k miles under there and no noticable wear on the tire or the bar. Just a clean spot on both. I feel like I've jammed as much tire as I can down there, but it's not a full fledged Method/Falken WP, just an OEM FJ Cruiser tire I bought off craigslist. It's worked for me before when I got a puncture so I'm happy.