Dunlop Extends ‘Touch Technology’ with SP StreetResponse
In March we mentioned that Dunlop was introducing its SP StreetResponse range at the Geneva Motor Show. For those of you seeking further information on this new summer tyre in these pages, the wait is finally over….
According to Dunlop, the developmental aim held by the SP StreetResponse design team was to produce a tyre that offers drivers of small city cars superior dry handling qualities without compromising on wet performance or rolling resistance parameters. This strong dry handling emphasis was to be provided courtesy of what Dunlop calls ‘Touch Technology’; the manufacturer comments that the SP StreetResponse is its first standard tyre to include this innovation.
Dunlop explains Touch Technology as a combination of “a number of sophisticated tyre technologies such as Multi Radius Tread Technology (MRT), a specific bead seat system, a flatter tread profile and an asymmetrical tread design with a variable land to sea ratio.” When put together, the manufacturer continues, these technologies “ensure better road feedback, better steering precision and cornering stability, as well as enhanced grip on dry road surfaces.”
“The new Dunlop SP StreetResponse is the right tyre for drivers of small city cars who want to enjoy driving in an urban environment – providing an excellent mix of performance in both wet and dry conditions,” said Frederic Schilling, Dunlop brand director for Europe, Middle East and Africa.
The tyre’s tread design features wide circumferential and lateral grooves; these, reports Dunlop, ensure maximum water dissipation and aquaplaning resistance. Bi-directional sipes and notches in the central rib have been put there to enhance wet surface grip in curves, the tyre maker explains. Furthermore, it says the presence of L-shaped and Z-shaped sipes on the shoulder blocks should ensure excellent acceleration and braking on wet roads.
The tread compound used in the Dunlop SP StreetResponse is described as containing “an advanced tread compound with functionalised polymers that ensure better wet grip without compromising rolling resistance.” Functionalised polymers, elaborates Dunlop, ensure a strengthened interaction between the silica and polymer and a better distribution of the silica in the compound. This is said to ensure a reduced energy loss for good rolling resistance levels, while improving key performance parameters such as wet handling and braking.
Returning to Dunlop’s Multi Radius Tread Technology (MRT), the manufacturer notes that tyre tread patterns are conventionally developed on the basis of three different radii. MRT design employs ten different radii and therefore, says Dunlop, is more precise and the pressure across the tyre is managed more effectively. The effect, Dunlop adds, is a significantly better control over the evolution of the footprint in driving conditions: “The shape of the tyre changes more smoothly when it moves from a straight to a curve, leading to more precise and progressive reactions.”
The new generation of Dunlop tyres features a flatter tread profile whose contact patch is, depending on size and type, four to eight per cent larger; this delivers, says Dunlop, better impulse, more stability and enhanced road feedback, allowing tyres to respond quicker and more precisely. Another MRT component, the asymmetric tread design with a variable land to sea ratio, is intended to provide improved aquaplaning resistance. As Dunlop explains, the continuous centre rib increases stability and precision, while the asymmetric groove arrangement enhances grip on wet and dry surfaces and the outer shoulder block delivers improved cornering control. According to the manufacturer, the result of these features is that drivers will experience a more relaxed motoring thanks to the tyre’s improved performance in both straight line and heavy curvature driving.