Thats a challenging one. I have been running radial rear tires and I am liking them. Currently have dunlop quadmax sport on the rear. But unfortunately they are discontinued. SO next set of tires I am going to buy is ITP holeshot SR radial rears. They seem to hook up better and is about the only thing that my zilla will hook up with on dirt. Also used these tires at bull gap this past year on my honda 250r and beat my buddies 850 sportsman to the top of the hill every time and he was even in four wheel drive!! No issues with punctures or anything either.