Racing plays a pivotal role in developing sport or track-day tires, and in the case of the new Diablo Superbike Pro slicks, it was American-style endurance racing. In Europe, FIM endurance rules limit fuel capacity and allow for quick-change wheels, so teams change tires during the frequent gas stops. American rules shy away from quick-change wheels while permitting large-volume fuel tanks, so teams ride much longer on a set of tires.
To fill this need, Pirelli created the Diablo Superbike Pro slick. Looking to combine race-worthy performance with outstanding durability, the Diablo Superbike Pro is intended to be the tire for both endurance racers and track-day junkies looking for a long-lasting tire. Developed with input from seven factory teams and over two dozen professional riders - plus Pirelli's own engineers and test team - these new Pirellis were designed to be used without tire warmers, and have damping qualities that are meant to work with stock suspension components.
The Diablo Superbike Pro uses a specially developed compound, and sports a profile more akin to the Diablo Supercorsa as opposed to the more aggressive World Superbike-spec slicks. As always, the Superbike Pros are based on Pirelli's zero-degree steel-belted construction, but with more carcass flex than their DOT-spec counterparts to complement the new tread compound. The slick design not only gives them more traction and better feel than DOT tires, it also eliminates the tread grooves that can act as starting points for excessive tire wear due to improper suspension setup or tire pressures.
The Superbike Pro's compound is softer than Pirelli's SC2 (medium) compound when the tire is cold, providing more grip your first lap out and quicker warm-up. Once up to operating temperature, the Pro compound is harder than a hot SC2 tire, which improves mileage and allows the tire to perform better under a wider range of track temperatures. Chemical stabilizers and reinforcing agents resist hardening due to heat cycles, so tire performance remains consistent throughout an endurance race or over the course of several track days.
To get a feel for these new tires, we mounted a set on a Triumph Daytona 675 and hit up as many track days as the budget allowed. And we found the Diablo Superbike Pros to provide enough grip to run an A-group pace while wearing like iron.
Of particular note was their tremendous heat-cycle stamina, enduring upwards of 50 cycles over the course of 400 track miles with no sign of bluing or hardening. The tread surface has worn cleanly, and by flipping the tires we've managed to wear them evenly and maintain their profile. And the wear dots show there's still life left in them yet.
Although the Diablo Superbike Pros still provide decent initial grip, they still need a lap or more to come up to temperature before you can lay into them. The new compound proved quite versatile on the different track surfaces and layouts, but as with all Pirellis, the tires are sensitive to pressure, although the Superbike Pros are far less susceptible to temperature-induced wear than standard SC2-compound Superbike slicks.
The Pros' increased carcass compliance is apparent when hammering on the brakes. You can feel the front tire compress and deform, which slows steering response a bit, but that deformation translates to a massive contact patch and excellent traction with no squirm or movement. The rear tire could be broken free easily enough, but in typical Pirelli fashion, the tire smears long before it slides, and spins up in a respectable manner.
Considering how long they're lasting, it's impressive how much traction the Pros offer. With their new compound formula and carcass design, Pirelli has successfully negotiated an excellent compromise between durability and grip. As slicks, they're not approved for street use, but for riders with dedicated track bikes (or a tire machine at home) or people participating in multi-day track events, the Diablo Superbike Pros are an excellent option.
Price: $180 front, $212-$216 rear
Pirelli Tire North America