Bridgestone – Bridgestone Other Tires, including Battlecross X30R motocross rears, 100/90-19 and 110/90-19 rear fitments and Battlax Hypersport S21R 190/55ZR17 rears, gathers the specialist sizes that sit outside Bridgestone's main category groups. Small as it is, this is a useful corner of the catalog, because these are the tires riders search for by name. The Battlecross X30R is a competition rear built for intermediate to hard terrain, using a tight knob layout and a stiff carcass that transmits power cleanly instead of squirming under a big four-stroke. The Battlax Hypersport S21R comes from the other end of the spectrum entirely, a street radial with a dual-compound tread that keeps the center durable while the shoulders warm quickly for hard cornering. Both share the engineering discipline Bridgestone applies across racing and street development. If you already know the exact model and size you want and it did not appear under the main Battlax, Battlecruise or Exedra groups, check here first. Sizes in this group are limited, so if you are chasing a particular Battlecross or Hypersport fitment it pays to note the exact code from your sidewall.