As with most manufacturers, Bridgestone’s street tire offerings run the gamut from long-wearing touring buns to DOT race tires intended to provide maximum performance for a single race or track day. The new S20 Battlax Hypersport tires slot somewhere in between. They supplant the BT-016 Pros — one of our favorite all-around street tires — and reside in Bridgestone’s versatile “Sport” category, which entails suitability for commuting, aggressive street riding and track days.
During the S20 press presentation at our hotel near the Portimao circuit in Portugal, Bridgestone Senior Product Manager Bob Graham presented us with a battery of charts depicting appealing upward shifts. Compared to the BT-016 Pros, the S20s are said to have better traction in the wet and dry, improved steering response and an increase in contact feel at full lean. New rubber compounds with slightly less silica offer faster warm-up and improved grip at all temperatures, while a revised tread design and some tweaks to the carcass construction yield a larger, more even footprint at all lean angles, resulting in an increase in traction and feel.
Bridgestone’s new S20 hypersport...
Bridgestone’s new S20 hypersport tires warm up quick and stick well enough to be used at the track. The tires offer more grip than the BT-016 Pros while remaining just as durable.
The S20s have the same profile as the BT-016 Pros and still employ a dual-compound tread design front and rear, but the segmentation has been adjusted. The front tire has more soft rubber on the shoulders while the rear tire has less. Research found that rear BT-016 Pros were experiencing increased wear midway up the shoulder as the result of hard acceleration coming off corners. The S20s address the issue by expanding the central, harder compound to encompass the area used at lean angles of 20 degrees or less. The broader center compound should help preserve the rear tire’s profile and contribute to more consistent performance throughout the tire’s life. Despite more grip and improved overall performance, Bridgestone says the S20s will achieve the same mileage as the BT-016s. In our experience that’s about 4000-5000 miles.
Tire introductions are some of the most exciting events we get to attend because the host provides a wide array of bikes to ride, and Bridgestone didn’t disappoint. I started the day on a Kawasaki ZX-6R, following former MotoGP racer Jeremy McWilliams until I got my bearings on the challenging 2.9-mile Portimao circuit. The S20s felt sure-footed after just one lap and were fully warmed up after two. Traction was sufficient to cope with full-throttle corner exits on the 600, but stepping up to an Aprilia RSV4 R and Yamaha YZF-R1 served to show how much traction the S20s have and how they behave when that traction runs out. A slight smearing sensation signals the beginning of a power slide, after which the rear tire spools up quickly but smoothly. Slides were progressive and easy to maintain, increase or end. Feel from the front tire wasn’t stellar, but traction proved to be excellent so faith followed. The S20s felt neutral while trail braking and didn’t mask or enhance any of the bikes’ inherent handling characteristics; the R1 felt smooth and stable and the RSV4 dove for the apex and shook its head at exit. Traction and feel at lean are noticeably better than the S20s’ predecessors. While the BT-016 Pros allowed you to ride at seven-tenths, the S20s let you turn it up a notch.
When the tires were changed at midday they had been flogged for eight 20-minute sessions (about the equivalent of your average track day), and showed very little wear. It takes a keen eye to spot the line separating the different compounds; it’s evidenced by a slight change in the wear pattern. All the bikes were rolling on stock suspension set up by McWilliams, and there was no uneven wear or scalloping along the large tread grooves.
A street ride around the Algarve region of Portugal the following day showed the S20s to be excellent street tires. We observed a conservative pace on the occasionally damp and often dirty country roads, and the tires stuck firm and felt warm to the touch when we stopped for coffee. The unpredictable nature of the narrow country roads required frequent mid-corner trajectory and velocity adjustments, and the S20s took them all in stride. We expected the S20’s long, wide tread grooves to cause the tires to track along pavement seams, but the on the highway ride back to the hotel we didn’t observe any tendency to wander.
The S20s are a terrific tire for the intended market, with grip and performance to satisfy most aggressive street riders and A-level track-day guys. Bridgestone will still offer the BT-016 Pros at a slightly reduced price, while the new S20s will be moderately more expensive. The S20s are available in four front and seven rear sizes, including 130/70ZR-16 front for all those CBR900 riders out there, and a new 200/50ZR-17 rear option. The common 120/70ZR-17 size front will carry an MSRP of $182.69, while 180/55ZR-17 rears go for $244.48. For more info visit www.motorcycle-karttires.com