I'm running 23" 489's on a 12" wheel right now on the cart, and they work great in the sand. This is the second set of 489's on the cart. I'd get them for the Rhino, but they only make them in a 3 ply version. I want at least a 6 ply tire because of the extra weight of the Rhino.
Ya I noticed they don't have a 589 in that size. Do you know of a cheap place to get the 489's? I just checked the pressure in my all-trails and they have over 15 psi in them. That may be my biggest problem. I'm gonna lower them next time out and give them another shot.