Sand Tires
 

I was at the ATV parts store today looking at some Skat Trak 5 Paddle gliders for my daughters Polaris 90. It looked small in height so I measured the 18" tire (as I was told by the sales guy) and it only measures around 15-16" in diameter. He said that they are 18" at the height of the paddle. Not sure about this but I don't want to loose almost 3" in ground clearance. Should I go to a 20" diameter or should this work okay?
Thanks