I purchased a 2006 Sportsman 800 this past summer. I have thoroughly enjoyed running the hills of WV with it. My main purpose for it is to plow my driveway in the winter. My driveway is part asphalt and part concrete. I live on top of a hill and my driveway is 1/4 mile long. The grade is 12-13%. I have heard that ATVs do well without chains, but my concern is the steepness of the hill. Should I invest in chains or not?