Video: Bridgestone Battlax Hypersport S21 Sport Tire Review

In order to get the most out of a motorcycle you need great tires. Bridgestone has proven itself to be very capable when it comes to producing high-performance tires—just take a look at the past seven years of MotoGP. But it’s taken until now for that MotoGP technology to really trickle down into the street-going sport tires you and I can buy.

Bridgestone chose the gleaming Yas Marina F1 circuit in Abu Dhabi to debut its new 2016 Battlax Hypersport S21 sport tire to the world's motorcycle press. The new S21 is said by Bridgestone to be the first of its tires to feature leading-edge design concepts straight from the MotoGP grid and is intended to replace the S20 Evo, which itself was a very good sport tire.

There’s always room for improvement though, and a number of new design features have been applied to the construction of the S21. The most significant is that the S21 is the first production tire to utilize Bridgestone’s “ULTIMATE EYE” technology that was used to design and develop the company’s MotoGP and F1 race tires. The U-EYE is basically Bridgestone’s proprietary tire dyno that can simulate and measure virtually any riding/driving condition with incredible accuracy. The machine has the ability to measure numerous parameters, such as contact patch size, tire deflection under extreme acceleration and braking, sidewall deflection while cornering, and heat transfer, plus a host of other factors.

The precise data collection capabilities of the U-EYE technology has led to numerous new design concepts on the S21, including a new tread design. The new groove pattern is claimed to provide more stability under braking and a more consistent grip level during acceleration. Both front and rear S21s also feature updated profiles: The front S21 receives a “smaller crown” (read: taller and narrower) profile with new groove positioning for a wider contact patch while leaned over to deal with the higher camber thrust forces generated by the increased lean angles. A new 3-Layer Construction with higher-stiffness bead fillers in the front tire is another product of the U-EYE technology. The rear S21 gets a “larger crown” (lower and wider) profile and redesigned tread groove location for 30 percent less slip area in the contact patch (meaning the portion of the contact patch that is actually slipping rather than gripping the pavement) while improving straight-line grip during acceleration.

Bridgestone has also incorporated a new compound for the outer shoulders of both the two-compound front and three-compound rear S21. The new compound is claimed to provide greater surface contact at the micro level between the tire and tarmac surfaces while at full lean for better grip, faster corner speeds, and more confidence in the turns.

While the aim of the new S21’s design is to increase overall grip and stability in addition to providing better feel, a side benefit is also significantly increased tire life, which Bridgestone claims is improved by 36 percent. The company also says that the new S21 lapped two seconds quicker than the S20 during testing at the Sugo circuit in Japan—all while still retaining the same wet-weather traction characteristics of the S20.

I was able to ride a number of bikes at Yas Marina shod with the new S21 tires, from 600cc middleweights to 1,000cc literbikes, from twins to four-cylinders. Consistently throughout all those rides, the first thing you notice about the new S21 is its stability. The tire provides a very reassuring feel. By that I mean there is no nervousness—just a solid connection between you and the road. Even at max lean, the S21 stayed in line whereas some other tires can get upset easily or tend to move around a bit. And the same amount of feel and stability was present no matter which bike I was on.

Corner entry was equally impressive, with the tire remaining very stable during hard braking and then the bike turning in nicely, though it does take a little more effort than some other brands to initiate turn-in. The flip side of that effort, however, is there’s no flightiness over bumps, and steering remains very precise, giving you added confidence. The transition from trail braking to max lean is also very good, with only the slightest sense of vagueness during the change.

Direction changes are another plus when it comes to the S21. Again, the tire needs a bit more muscle than usual to flick the bike from one side to the other, but it pays off with the Bridgestone providing a positive feel throughout the transition. The S21 rolls over very evenly, never falling in or fighting to complete the transition from mid to full lean and then back upright.

Overall grip from the new Bridgestone was excellent, especially for being a street-oriented tire. Granted, we were riding well within our limits during our time at Yas Marina, as the F1 circuit’s runoff in the turns is comparatively small due to its automobile-intended use; the walls and barriers are way too close for comfort in most areas of the track. When the S21 does start to protest at being ridden too aggressively, it lets you know with smooth, progressive slides that don’t threaten to put you on your head. Grip began to fade after a good number of laps, but again, the S21 is a sport tire, not a DOT race tire.

Ridden with moderate levels of aggression, the new Bridgestone S21 is a superb sport tire that can handle multiple roles with ease. It’s meant for everyday riding, but if you feel the need, the S21 makes for a very competent trackday tire as well. Bridgestone’s claim of extended mileage was hard to gauge by just racetrack sessions, but I will say that at the end of the night’s riding (the circuit’s location in the Middle East means that days are very hot, so the facility has a full lighting system that allows running during the nighttime hours), I felt more worn out than the new S21 looked.

The new 2016 Battlax Hypersport S21 comes in a variety of sizes that will accommodate most streetbike sizes. Prices were not available at press time.