The Speedball features a multi edged “S&M” shoulder tread design that looks cool & holds the ground while turning. The 20″ Speedball w/ its smooth unbroken center strip for less rolling resistance is primarily a Street tire w/ a center tread making them great for Dirt/Flat/Street/Park as well. The 20” x 2.10” is light & fast & work well in the front or rear – big enough for street riding but small enough to stay out of the way on grinds, spines, or frames & forks w/ minimal clearance.