MXR6 Front: 19x6-10, 20x6-10 (2 ply); Rear: 18x10-8, 18x10-9 (2 ply) An ideal choice for loose track surfaces, with wider-spaced split knobs for better bite and clear-out Rear MXR6 uses a new reinforced carcass for 2006; minimizes stretching while maintaining a flat profile, providing consistent feel and performance New carcass allows lower tire pressures, enhancing control as well as ride comfort Front MXR6 features a new, longer-wearing treead compound-more motos per tire! Unique 19 in. Holeshot MXR4 returns for 2006, still a great rear tire choice for extremely sandy or rough tracks. MXR4 Rear: 19x10-9, 19x10-10 (2 Ply).