- Published: Thursday, 28 April 2016 07:01
Bridgestone’s new Battlax S 21 spells serious competition for the hypersport tyre segment
Words Deyna 'Plain Crackers' Chia
Pictures Bridgestone Corporation, Michael Tan
Yas Marina Circuit, Abu Dhabi, UAE — It’s evening on the Persian Gulf, and the cool air is ripped by the sound of litre-bikes screaming past apexes: A Yamaha, a Kawasaki, then a BMW. It’s the sound of competition at the highest level and the singular pursuit of speed.
Yet it’s not the bikes we’re here to find out about. Rather, it’s the most important component of a motorcycle that helps it go around circuits at top whack: Tyres. Or in this case, a tyre.
It’s worth celebrating this occasion because it’s something that doesn’t happen very often: Bridgestone is launching its new S21 Hypersport tyre at the Yas Marina Circuit in Abu Dhabi and we’re here to test out its claims that it’s a significant improvement over the outgoing S20 Evo.
All Hyped Up
‘Hypersport’ is a nebulous term (like ‘crossover’ in the car world) and refers to the open-class category of bikes, including the superbike or litre-class (1000cc) and larger engine (displacement) sports or sports-touring machines like the Suzuki Hayabusa, Kawasaki ZX-14R and BMW K1300S.
Given the nature of modern machinery, in terms of performance and technology, hypersport can also refer to upper-mid-class sportsbikes (Triumph 675 Daytona, Ducati 959) as well as supernakeds like the KTM 1290 Super Duke R, Aprilia Tuono V4, BMW S1000R, Triumph Speed Triple, Ducati Monster 1200.
Despite the high-powered nature of the machinery it provides the shoes for, the S21 is, like the S20, not a racing tyre. Bridgestone’s brief remains the same: It’s aimed at ‘riders who enjoy sports riding, want a combination of wet performance and long life, and those who are thinking of starting on the racetrack’.
In other words, it’s high-performance tyre with a big focus on on-road performance, squaring off against the likes of the Pirelli Diablo Rosso Corsa and Michelin Pilot Power.
More Than An Evo
According to Bridgestone, their engineers took the ‘renowned wet performance of S20 EVO’ and combined it with innovative new features to improve dry performance and increase mileage.
The differences, and the claimed improvements, are many (see box).
So confident are Bridgestone, they've fitted the S21 to about every current model of supersport and superbikes for the test.
For the 600s: Honda CBR 600RR, Kawasaki ZX-6R, Triumph Daytona 675R, Yamaha R6.
The literbike side is almost a full house, only lacking Aprilia’s RSV4: BMW S 1000 RR, Ducati Panigale 959, Kawasaki ZX-10R, CBR1000RR SP, Yamaha R1 M, Suzuki GSX-R 1000 L5. The lone supernaked on test was BMW’s S 1000 R.
With six, half-hour sessions to put the S21s through the paces, I elected to ride the ZX-10, R1 M, S 1000RR, CBR 1000RR SP, Daytona 675R and Panigale 959. These leading models need little introduction and in my opinion represent the most precise (and popular) track and street scalpels we can get our hands on today.
Get Yer Yas Yas Out
The test session spanned six hours - 5pm till 12am - with an hour’s break in between. Conditions were good, ambient about 20 degrees and the F1-grade tarmac nice and grippy, not at all dusty. The Audi racing school had been using the track in the day-time in the past week, leaving rubber in a handful of corners, but nothing slippery or (additionally) grippy out of the ordinary.
Yas Marina Circuit’s twenty-one (21) punishing turns, coupled with acclaimed track surface grip levels, would have shown up any kinks in the S21's claimed repertoire of improved dry performance and durability.
We were given some rather special visual proof of the new durability claims: Following lead rider Josh Brookes (World Superbikes racer and British Superbike champ) Josh would light up (as in smoke) the rear tyre exiting Turn 14, lap after lap. He rode the entire six-hour stint with the same S 1000 RR and would have enough grip (strangely) to stay far ahead of me. Clearly no issues with durability - if you’ve talent to spare, that is.
With each successive lap, I was able to up the pace and push myself and the tyres. More liberties could be taken with corner entry speed, later application of threshold brake force and more trail braking through the turn.
After three stints, we felt more familiar with the S21, and for good reason: We were able to lean on the S21’s front tyre like more track-biased tyres such as the Pirelli Diablo Supercorsa SC2 and Metzeler Racetec RRs, both of which we’ve tested extensively at our ‘home circuit’ of Pasir Gudang. The S21 exhibited superb stability in terms of braking, turn-in feel and response, and ability to hold the line exiting corners. It was especially useful when getting used to unfamiliar machinery - it was our first time on the ZX-10R, R1M, Panigale 959 and CBR 1000RR SP before.
The rear S21 offered similar "security" but did move a little when powering hard out of corners (not forgetting quite a few were negatively cambered) with the litre bikes. The S21s also gave confidence when accelerating out of Turn 9 to an indicated 270+km/h before applying firm brakes for Turn 11. Talking with other testers, sentiment was unanimous, that compared with S20 Evo, the S21 had clearly raised the bar, with the front tyre being exceptionally good.
Hot (tyre) pressures were 2.2 and 2.3Bar, rear and front respectively. Visually, tyre wear was spot on, on all the bikes. Having tested the S20 Evo at Johor Circuit some months back, first impressions of the S21 are extremely positive, impressive, to say the least.
Having tested the outgoing S20 Evo with a stock Triumph Daytona R at Johor Circuit a few weeks back, the difference in feel and grip with the stock Triumph Daytona R fitted with S21s at Yas Marina Circuit was immediately apparent.
On a scale of 100, I would have ridden at 85 percent (of ability and daring) at Yas Marina. The S21s performed predictably, almost surprisingly, given how much mechanical grip was demanded and “abuse” thrown at it.
Riding at 70 percent with the S20 Evos at Johor Circuit (bearing in mind the mechanical grip of the circuit is quite a few notches below YM), the rear S20 Evo would “let-go” whilst getting on the gas early at Turn 3, whilst the front exhibited a small “tuck” when trail braking into Turn 5. Most experienced riders will appreciate how much easier it is to save a rear wheel slide than a front tyre slide. The improvements made to the front S21 tyre are significant, even over-shadowing the improvements to the rear S21.
If the test at Yas Marina proves a true representation of what we can expect back home on our streets and circuits, what Bridgestone has achieved with the S21 is a big, big leap over the S20 Evo.
It’s built sporty street tyre for the fast road and weekend track warrior that can rival class leaders like the Pirelli Rosso Corsa for sportiness, and the Metzeler M7RR for durability. Given how often performance and longevity seem to be mutually exclusive in high-performance motorcycle tyres, we’re eager to see what the S21 can do in Singapore’s more challenging riding environment.
Battlax Hypersport S21 comes in four front and six rear sizes
Check out Singapore pricing for the Bridgestone S21 tyres here