My dealer said I needed 3" spacers for rear chains on my B-2601. I have run two different types of chains and find them way too rough on my back with the bouncing. So I switched to Kold Kutter screw in studs. Unless I am pushing up hill on a 10% slope, the wet stuff the State plow pushes in, I have no traction issues. Drive is 25' wide by 100 yards. Then a 100' by 50' parking area. Granted it has been a light snow year, only 16', about 11' less than normal. The studs work great.