Pirelli Diablo Supercorsa
Before we headed out to Buttonwillow Raceway for the track portion of our middleweight comparison test, we equipped each bike with Pirelli's latest DOT race rubber, the Diablo Supercorsa. A direct result of the company's continuing involvement with the World Supersport Championship as that series' spec tire, the Diablo Supercorsa incorporates numerous features aimed at serious corner-carving performance.
Compared to the old Dragon Supercorsa, the Diablo Supercorsa has a much taller and more triangular profile that presents flatter areas on the shoulders to increase contact patch size at moderate lean angles, and provide more traction and improved feedback entering and exiting corners. The tires' internal construction has been changed, with the front tire getting additional cross plies to help with stability under braking; both still utilize the zero-degree steel belt design that runs steel threads along the circumference of the tire to provide stability and reduce tire growth at speed. The near-slick tread design puts the maximum amount of rubber on the pavement, and there are four different compounds offered (contrary to current trends, the Diablo Supercorsa's construction only uses a single compound).
We used SC2 compounds for our track testing at Buttonwillow, in 120/70 front and 180/55 rear sizing. The tires were a bit taller than many of the stock OEM fitment rubber (with the exception of the Triumph, which comes equipped with the Diablo Supercorsa "SP" street/track version stock), but adjustments were easily handled within the range of stock components.
As before, all our testers found the Pirellis to offer superb grip over the course of the day, with light and neutral steering habits. The front tire provided excellent feedback and allowed easy trail-braking into corners; the rear was a little numb in comparison at max lean, but still offered excellent traction with good bump absorption.
As per our usual test regimen, we attached our Racepak G2X data acquisition system on the back of each bike during Kento's timed laps at Buttonwillow Raceway. The GPS speed data graph at right shows some interesting correlations to our subjective comments; the top row of the graph designates where each section signifies a particular section of the racetrack. Unfortunately the times and speeds in the following analysis are not directly comparable to our previous tests for two reasons: First, the exact designated points on the track for each analysis area are slightly different due to logistical issues. Second, the lap times are significantly slower than our previous tests at Buttonwillow, which we can attribute mostly to the deteriorating pavement surface and the numerous pavement sealer patches in various turns that proved to lack decent traction.