Not a question I hear often. LOL! Well BigBull, I have worked at Carlisle Tire and Wheel Co for 34 years, in various positions. We are one the largest manufacturer of lawn and garden, industrial, utility trailer and ATV tires in the United States. You are asking a big question. I don't know what is on your machine now, how you ride it, or what kind of riding you do, but the selection is fantastic. The tire size of your machine is usually based on a number similar to the following: 25x12-10. Just in case you don't know what that number means, I'll explain. Again, 25x12-10! The 25 means that the inflated tire is 25 inches high from the ground up. The 12 means that the tire is 12 inches wide "inflated" at the bead, and the 10 means that the machines wheel is 10 inches in diam. You have to stay with the last number unless you change wheels too. The front wheel and the back wheel are usually 2 different sizes. The front tire is typically narrower. Not always, just usually. Tire treads run the gauntlet from 1" square blocks over the whole tread area, to cross bars like a tractor tire. Each version has a following and that following swears by their favorite design. Now I'll give my favorite and I can get whatever design that I want. I've tested quite a few designs. I like Carlisles TRAIL WOLF design. I have those on my personal machine. I am a hunter and a trail rider, NOT a racer. The TRACTOR SUPPLY stores and the local WALL MART SUPER CENTER both handle our line of tires. You can go slightly bigger, height and width, both front and rear, but you need to understand the ATV factory has invested considerable time, effert, and money in getting the sizes right for the power range of your machine. Check out the Carlisle web site at
www.carlisletire.com Hope this helps! Bill................