Sports tyres are going through quite the metamorphous these days. Yes, they are still black and round and for the most part sticky, but they are no longer allowed to be good at only one thing.
If you’ve ever ridden on slick tyres at a racetrack you’ll know the riding is only part of the endeavour. There’s stands, tyre warmers, generators, probably a bunch of other stuff in there I’m forgetting you need to worry about, and you still need to ride fast enough to get the tyres into a working window where their grip can be properly exploited. Ride below that threshold, and they won’t retain the heat required to make them work and they can become downright dangerous.
As such, the market for a tyre that can fulfil a bunch of different needs is becoming more important to the world’s manufacturers by the year. And bringing all that extra stuff to the track is a pain in the arse, anyway.
Bridgestone’s Battlax S22, released in 2019, filled this one-tyre-fits-most role very well, but it’s now been superseded by the Japanese company’s latest offering in the S23.
The S23 comes to dealer floors in a very busy time with Dunlop’s Sportmax Q5, Pirelli Diablo Rosso IV, Michelin Power 5, and Continental’s ContiSportAttack 2 all offering exceptional street and track performance at competitive prices.
“The S22 was a really good product for Bridgestone so we were not exactly starting from a blank canvas. We kept the form and the shape of the S22 in the S23’s construction, and we just finetuned all the aspects to make it better in the more extreme conditions this tyre experiences.”
In S23 guise, Bridgestone is claiming a five percent higher cornering speed, a one percent faster dry lap time, a three percent shorter wet braking distance and a four percent faster wet lap time.
Whether any of the lap time stuff really matters is up to you as this is a sports tyre that can go to the track, not a race tyre designed for ultimate lap times. However, the braking distances and cornering speeds should be something worth noting, especially if you’re riding in the rain.
The S23 runs a new compound in both the front and rear using Bridgestone’s MS-Belt construction. Both ends are stiffer in the sidewalls than in S22 guise, allowing for less deformation, and more stability and grip at high lean angles, while a harder centre compound in the rear allows for a claimed eight percent increase in mileage. In all, the front tyre runs three compounds (3LC), while the rear runs five (5LC).
“The front tyre’s new construction and compound allows it to be more durable for mileage but is also stiffer so it holds its form (shape) better when you’re on full lean on the racetrack,” Plom says. “The tyre also heats up faster, so the rider has the confidence to push harder, earlier. You’ve got a much more stable front tyre and this allows for a higher cornering speed.”
Look at the S22 and the new S23 side by side and the first thing you’ll see is a fairly different tread design. The front tyre runs fewer longer centre grooves, doing away with the more plentiful shorter centre grooves of the S22, giving the S23 a superior Land-Sea ratio and allowing for greater water dispersement.
On the rear, Bridgestone’s Pulse Groove technology that debuted last year on the T32 sport touring tyre is the dominant feature. The Pulse Groove concentrates the waterflow into the centre of the groove, speeds up the water dispersion to get it out of the way and allow the part of the tyre void of the grooves to do its job and stick to the road. Again, this means a greater Land-Sea ratio and more tyre on the road when you need it most.
The chance to test this new Bridgestone S23 came at the stupendous Kyalami circuit on the outskirts of Johannesburg in South Africa. Kyalami has gradually faded from the international racing conscious after last hosting WorldSBK there in 2010 when the government bought out the contract with then WorldSBK owners FGSport (remember them?) with three years still to run in the wake of the 2009 Global Financial Crisis.
The track was bought by South African businessman Toby Ventor in 2015, Toby being the local distributor for Porsche, Lamborghini and Bentley. Oh, he also owns the rather posh Uva Mira Mountain Vineyards, so he’s good for a tasty drop or late apex, whatever you fancy.
Kyalami’s walls have gradually closed in over the years so you’ll probably never get WorldSBK back there unless big changes are made but that doesn’t discount the fact it is an absolutely fantastic circuit, especially for testing.
Lots of changes in elevation, a number of front-end testing hard braking zones, and one of the best corners in the world in the fourth-gear downhill left-hander known as The Mineshaft (not too dissimilar to Stoner Corner at Phillip Island) will put any machine or rubbery thingy through its paces, and it was a toasty 35°C air temperature, so that’s another factor to consider.
Putting street tyres to the test on the racetrack always adds an element of excitement. Striking the right balance is key — push too aggressively and the limitations compared to dedicated racing tyres come up real quick, while being too conservative won’t showcase the improvements over the previous model.
Back in 2019, the S22 won me over after a particularly heart-stopping pursuit of my colleague Adam Waheed at Jerez in Spain. The tyre’s ability to handle intense, repeated front-end buries without letting go left a lasting impression for a street tyre that didn’t use warmers. Fast forward to the 2020 KTM 1290 Super Duke R launch, the S22 proved its mettle once again, each set enduring over 130 laps at Portimao. Despite diminished grip, it surpassed expectations for a tyre in such condition.
Nearly four years later, the S23 maintains the commendable characteristics of the S22. Bridgestone’s renowned front tyre feel, a staple from the heights they scaled in MotoGP, remains intact. The Mineshaft corner at Kyalami, with its high-speed left-hander followed by a low-speed, hard braking right-hander, provided a perfect testing ground.
Heading into the right-hander at Mineshaft showcased the tyre’s improved speed of direction and reduced flex at lean, enhancing handlebar feedback. While the rear S23 delivered excellent acceleration at Kyalami, the southern hemisphere’s summer heat did cause a gradual decline in grip after about five hard laps. Nevertheless, the tapering was minor, and grip remained consistent throughout 10-lap sessions.
As a front-end feel enthusiast, the S23 instilled the confidence to push the limits across various machines. I started the day on a BMW S 1000 R, not the ideal machine to learn the track, I’ll admit, but then stepped down to the KTM 890 SMT, a less intimidating motorcycle but one still capable of stressing the rear tyre on acceleration.
Throttling mid-corner and unleashing power, especially on high-performance bikes like the R1 and Super Duke, did put stress on the S23, but the wear on smaller bikes like the 890 Duke R was negligible. Rear grip on 120-ish horsepower bikes remained impressively consistent from start to finish.
Wind the throttle on while cranked right over and the edge grip is impressive. You can feel the edges of the tyre flex under heavy acceleration from powerful bikes like the Super Duke but in true Bridgestone fashion the grip is predictable and consistent.
Acceleration grip is definitely improved on the S23 but it’s more the feel you get through the seat that’s the real winner. The S22 wasn’t overly lacking in this area but the S23 takes it up a notch, allowing you to stand the bike up on the meat of the tyre and really punish it to gain the most acceleration possible.
Into turn one’s near dead stop left hander under hard braking, the S23 turns sharper and faster than the S22. The front tracks superbly, admittedly thanks to Kyalami’s near billiard smooth surface compared to the Johannesburg roads just outside the track gates, but the difference between old and new is noticeable.
While wet weather testing was unfortunately omitted, the S23’s stellar dry weather performance endured over 100 laps with diverse riding styles and speeds, even in scorching track temperatures exceeding 50°. This robust performance attests to the S23’s longevity and reliability on the track.
The S23 has some serious competition to deal with, more so than the S22 had to during its 2019 release, and much of the debate will not so much be around the lap times it produces but how long it lasts. This is a street tyre, after all, but given the number of laps with no tyre warmers the S23 took at Kyalami, the wear signs are good for street riders.
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