Even if Polaris did balance them, how long do you think they would stay balanced? ATV tires have very low air pressure, giant lugs, and suspension systems designed for off-road. Balancing them is a nice idea but it would not last past the first trail ride.

Believe it or not ATV tires twist on the rim....they are under such force, and run at about 4-6 PSI. This is why racers run bead-locks because without them the tires actually can spin on the rim....so any balance that is there from the factory would be gone after the first aggressive ride of smashing into rocks and trees......

Maybe there is another reason beyond balance that is causing your shimmy. Perhaps something is loose, or your alignment is off, or a tire has a bad spot, or your air pressure is not equal on left/right, or your suspension setting are not equal left/right......