Concentrating on performance – Avon's ZZ5
Earlier this year Avon Tyres launched a new top-end product to replace its ZZ3, a range that represented the Melksham-based tyre maker in the W and Y speed rated categories for the best part of a decade. This new tyre, the ZZ5, slots into the Avon performance hierarchy above the three-year old ZV5 and serves as both the brand’s flagship product and most dedicated performance offering. In October, Tyres & Accessories met the team behind the new tyre’s development and got to know their handiwork a little better.
The ZZ5’s introduction fills more than just a gap in the Avon product portfolio. While the Cooper Tire & Rubber brand’s current passenger car range covers a broad spectrum of sizes and begins with T rated, 13-inch rim diameter fitments, over the years Avon has been known for its focus upon the performance and sport segments. It is therefore important that Avon is well represented there. With this in mind, Malcolm Jones, European product manager at Cooper Tire & Rubber Europe, shares the company “felt Avon needed a new star at the top end – a solely Y rated range that concentrated on performance.”
Once the decision to produce a dedicated performance tyre was taken, the first step for the tyre development team at Cooper Tire & Rubber Europe’s ETC, or European Technical Centre, was to ascertain exactly what sort of performance a performance tyre needs. Outlining the ZZ5 design process, ETC general manager Gavin Edwards explains that the initial stage of the tyre’s development involved gathering feedback from customers and dealers on qualities considered most important: “This information formed the basis of our development targets. Then we benchmarked against competitor and tier one products before launching four development programmes, which covered compound, profile, construction and tread pattern.”
Developing the ZZ5
Edwards reiterates that the ZZ5 was developed primarily as a UHP tyre with a focus on attributes most relevant to this sector, namely grip, especially wet grip, and handling. Thus, using a silica compound was a matter of course. “We’ve invested in machinery and processes that have enabled us to progress to the third generation of silica technology,” the ETC general manager shares. “Our new intermesh mixers improve control in mixing, and with these we can better control the silanisation process.” The result is what Avon calls a HD (high dispersion) silica tread containing cross-linked polymer with more highly dispersed silica particles; in other words a more dispersed silica matrix, which allows for improved wet performance and better wear characteristics. Rolling resistance was also a development consideration, yet optimisation of this attribute was carried out in the context of the tyre’s intended high performance focus.
Summing up the various technologies that went into the ZZ5, Edwards reflects that a “good tyre is a marriage of various individual components and technologies.” Therefore the emphasis on performance characteristics shown in compound development extended to the design of the ZZ5’s mould profile. The tyre developers at Melksham decided upon a ‘Tri-Arc’ mould shape, which was developed to improve handling and tread wear and give better contact pressure distribution. The same focus applied to construction; Avon’s boffins packed the ZZ5 full of features intended to optimise performance, including flipper reinforcement for improved steering response and lateral stability and a 0° spiral restrictor to improve high speed performance. A 2-ply rayon casing was used to give crisper, more predictable handling. As for the tread pattern, Gavin Edwards comments that it has two functions: “It must be pleasing to the eye while serving its purpose.” The asymmetrical pattern is an obvious visual nod to the tyre’s performance focus, while features such as its longitudinal grooves (designed to maximise water clearance), large shoulder tread blocks (for improved traction and handling performance), central tread rib (designed to improve centre feel and precision handling) and ‘opti-noise’ tread pattern (which focuses on reducing road noise) take care of practical considerations. The ZZ5 also features a rim flange protector that, in the words of Malcolm Jones, “actually works”.
Some 10,000 kilometres worth of testing was carried out on the ZZ5 before its market launch. A good chunk of this took place at the MIRA facility in the UK, where wet and dry testing was carried out. Other ZZ5 test locations include Fontage in the south of France, where aquaplaning characteristics were evaluated, Idiada (Spain), Kerpen (Germany), where noise testing was carried out and the Nürburgring circuit, which hosted high speed, durability and handling testing. Avon’s ETC team also have access to Cooper Tire’s extensive proving ground in the US state of Texas, a facility Edwards says is ideal for dry testing during winter and thus speeds up product development times. Tyre wear for the ZZ5 was field tested in the UK.
Testing in the UK and abroad
Gavin Edwards refers to Avon’s development goals for the ZZ5 as “far-fetching, but realistic.” As mentioned earlier, ZZ5 development was benchmarked against a competitor product. The team at Avon haven’t disclosed which European manufacturer’s product was selected to be this competitor benchmark, however Gavin Edwards states the ETC “aimed to go way above the competitor.” Compared with the benchmark tyre, Avon reports similar dry braking performance and improvements in the area of wet braking, wet circles, wet handling and dry braking. Track testing shows wet handling to be a particular ZZ5 strength.
In keeping with its role as Avon’s performance flagship, the ZZ5 is only available in the larger 18 and 19-inch sizes, all of which are Y speed rated. At present the range consists of nine sizes, and more will be introduced next year.
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