Cooper’s new flagship outperforms predecessor ‘in every area’
The United Kingdom is Cooper Tire’s strongest European market. The company holds a 7 to 7.5 per cent of the consumer market here, thanks largely to healthy 4×4 tyre sales. Market share on the other side of the English Channel and in the PCR segment is more modest, however, and Jeff Schumacher would like to see this change. Schumacher, who took on the role of Cooper Tire Europe’s managing director and vice-president at the start of this year, aims to increase combined market share for all Cooper brands to five per cent across Europe. To achieve this, the company has opened a new branch office in Russia, is increasing market penetration in France and Germany and signing on new brand ambassadors. Furthermore, in September Cooper unveiled a new range-topping passenger car tyre, the Zeon CS Sport.
This latest UHP range was developed at the tyre maker’s European Technical Centre in Melksham, Wiltshire and succeeds the Cooper Zeon 2XS. Pete McNally, Cooper Tire Europe’s technical director, says the Zeon CS Sport “outperforms the 2XS in every area”; he reports a five per cent improvement in dry road holding courtesy of an increased footprint and more rubber on the ground (up 18 per cent in size 235/35R19, for example), while the new tyre’s void area – grooves for clearing water – is 33 per cent greater than on the 2XS, giving the CS Sport better wet grip. The tyre’s wet weather credentials are confirmed by its label result – every size in the Zeon CS Sport range has been rated ‘A’ for wet grip. Rolling resistance ratings are as expected for a UHP tyre and fall between ‘C’ and ‘E’, depending on size.
“One of the design considerations was achieving an ‘A’ for wet grip,” comments McNally. “We also wanted to improve dry roadholding by five per cent compared with the 2XS without compromising on wear. For the driving enthusiast, the CS Sport is the ultimate tyre; it performs exceptionally well in wet and dry conditions, with great steering response and handling. We’re very proud to offer it as our flagship tyre.”
Discussing the various elements that make up the Zeon CS Sport, McNally says that “one of the big things with this tyre is the tread technology.” He elaborates: “You’ve probably heard people talking about silica for many years now, it’s become one of the big things in our industry. But it’s how you use that silica, how you process it that makes the difference.” The technical director shares that the Zeon CS Sport uses Cooper’s third generation of silica and polymer technology; the first being silica in emulsion SBR (styrene butadiene rubber), which was processed in water, and the second being solution SBR, which used a solvent rather than water to disperse the silica in the rubber.
“The difficult thing with silica is that when you mix it, it tries to group together,” explains McNally. “The difficulty is ensuring it is highly dispersed and keeping it dispersed, as even after you’ve mixed it, it tends to get back together. So, we’re on our third generation now – highly dispersed silica in a functionalised SBR. And the functionalised part involves long molecule chains that keep the silica particles apart. This is what optimises our tread compound.” He adds that the silica particles are dispersed throughout the rubber compound using intermesh mixers.
As for the tread itself, McNally says Cooper used intelligent asymmetric tread design, or IATD, for the CS Sport: “It’s a flashy name but what does it really mean? Well, the big difference between this and our previous tyre is that it has very wide longitudinal grooves to clear as much water as possible. It’s got large shoulder tread blocks to improve traction and minimise wear. There are large central ribs to improve centre feel and precision handling, and the CS Sport has got an ‘Opti-noise’ tread pattern that employs advanced pitch sequencing. To keep noise down, we’ve varied the size of tread blocks, so that each one is slightly smaller or larger than the one next to it. Varying the pitch of the sequence around the tyre reduces noise levels.”
The Zeon CS Sport casing is made from 2-ply rayon. “A lot of companies use polyester as polyester is cheaper and easier to process, but rayon doesn’t stretch and therefore the tyre is much more stable, especially at high temperatures,” comments McNally.
The new, UK-manufactured tyre sits above the CS6 (which, incidentally, will be replaced by the CS8 in 2014) in the Cooper range and will be available in the European, Russian and Middle East aftermarket from January 2014 in 17 sizes for 17 to 19-inch rim diameters and with W and Y speed ratings. Jeff Schumaker says Cooper benchmarked the CS Sport against tier 2 competitors such as Hankook and Toyo with the aim of “delivering similar or slightly higher” performance, and the tyre is targeted at drivers of performance vehicles such as the Ford Focus RS and upmarket saloons such as mid-sized Audis and the Jaguar XF.