This high performance tire was developed for racing and has further evolved in performance. The Battlecross X31 is for a broader range of intermediate terrain in big bike sizes. Starting where the X30 left off, the X31 is enhanced with Bunker GrooveT technology which works by improving casing flex for enhanced traction in harder terrain and adds biting edges for traction in softer conditions. For intermediate terrain. Anti-Degradation Fin™ for front and rear. Note: NOT for use on public roads. Tire Specifications: Load / speed index: 51M. Construction: Bias. Standard rim (inches): 1.60. OD (mm): 710. TW (mm): 95.