Rubber at the interface of intimate contact is the primary determinant of pleasure and safety.
Shoes, for example. You have your running shoes, your cross trainers, your tennis shoes, your football boots… Good ones can elevate your performance and enjoyment, crummy ones can ruin your ability. Crummy shoes can also ruin your knees. And so it is with tyres.
To that end, tyre design is an exact, exhaustive, continually innovative engineering effort. To corral such extremes of physics as that which a car places on its contact points – at high speeds on all manner of different surfaces wet and dry – is no mean feat.
Hence, simply looking at Bridgestone’s press release for their new flagship comfort-oriented tyre, the Turanza T005A, what with its masses of graphs, diagrams, esoteric technological jargon and statistics, is enough to cause uncomfortable flashbacks to pimply teenage years sat interminably in the shadow of giant textbooks and droning lecturers.
How does the company develop, test, and today demonstrate the virtues of its shiny new touring tyre? Why, at its very own gigantic proving ground, of course!
One of many owned by Bridgestone around the world, the sprawling 130-acre complex in Ayutthaya, Thailand includes a 3.3km high-speed perimeter track, a multi-purpose test pad, dry and wet handling circuits, and a variety of surfaces mimicking results of governmental neglect that your dinky little car will have to plod over in the real world.
It is here that Bridgestone staff eagerly put us through a series of “driving experiences”, each designed to illustrate how technological elements in the new Turanza translate to real, perceptible effects.
Bridgestone clearly believes in the new T005A. Their brochure proudly presents a hexagonal spider plot confidently proclaiming improvements in all characteristics of ride comfort, quietness, wear life, fuel efficiency, dry handling and wet braking. Smoother, quieter, safer – grand claims, these. We shall see.
We start off huddled beneath a tent under the punishing Thai sun, spectators to a paradoxically wet strip of long tarmac watered by surface-level nozzles.
From afar a Camry shod with the previous-generation GR-100 tyres comes barrelling down, 4-cylinder wheezing desperately before the driver slams on the brakes and the saloon comes to a halt not far away. Another identical grey Camry, but bestowed with the new-model rubber, does the same routine, only this time terminating its screech approximately a full car-length sooner.
We have it explained to us that chamfering at the edges of the tyres’ tread ensures a flat contact surface with the road despite heavy braking loads, where previously tread-edges had a tendency to deform inwards. By Bridgestone’s measurements, this yields a like-for-like 5% improvement in wet braking distances. The engineers smile smugly.
Back-to-back rides in cars shod with old and new tyres on the rutted, rough and cut-up surfaces of the proving ground’s real-world testing section reveal that a combination of innovations does yield a surprisingly perceptible improvement in noise levels and smoothness.
Each tread block from the inside to the outside shoulder of the T005A has been given its own unique pitch and pattern to reduce resonance and improve quietness, while high-angle sipes (the diagonal slashes that join two tread trenches) soften tyre impact on the road. The end result is a ride that roars less on broken pavement.
A fine analysis during development of pressures at the contact point has also allowed Bridgestone to mould the T005A’s tread shapes into one which exerts a more uniform pressure pattern, reaping clear benefits in refinement. More robust sidewalls also minimise deflection of the car, and the instructors’ comparative lack of steering correction while driving the cars wearing the T005A is evident on observation.
Comfort aside, however, these design elements combine with a new compound infused with what Bridgestone calls Nano Pro-Tech to deliver greater surefootedness. Because what is tyre design without a healthy dose of materials engineering, and what is comfort without a confidence of gait and control?
Behind the sci-fi name, Bridgestone’s trademarked technology is claimed to strengthen the bond between silica and polymer, reducing heat generation and energy loss.
All that scientific mumbo jumbo is well and good, but after the pottering around, we are keen to get a first-hand feel of how they all come together at high speed. Bridgestone obliges us, and we’re unleashed on the handling tracks and high-speed perimeter road, where we scoot through lane changes, slaloms and full emergency brake stops.
Does the new tyre acquit itself better than the previous tyre? Yes. Does it grip harder and convey that all-important assurance of safety? Yes. Is it, as its maker claims, quieter, smoother, safer? Yes.
You might never have known how fine a science tyre-making actually is, but at the end of the day, mission accomplished for the Bridgestone Turzana T005A, I would say.