I just bought a set of XTR's and both of the rear have a side to side wabble. The rim is true, but the tires move in and out about a half of an inch. has anyone else come across this? is there anything that i can do about is other then sending them back?

 

could add some air. that should stiffen the sidewall some

 

I had a pair of Swamplites that did that. The tread pattern seemed crooked. The good guys at Mudthrower.com took them back and sent me new ones.
The way I checked was I jacked up the rear of the ATV and hit the throttle. It showed up instantly.
Buck