Pirelli Diablo Superbike Pro Slicks

Pirelli is quick to point out that racing plays a pivotal role in developing tires, and in the case of the new Diablo Superbike Pro slicks, it was American-style endurance racing that directed development. While European endurance racers tend to change tires every time they stop for gas, American teams usually run for fun on a tight budget and ride their tires to the cords. To satisfy the American market Pirelli created the Diablo Superbike Pro slicks, which combine race-worthy performance with outstanding durability. Developed with input from seven factory teams, the Pros were designed to be used without tire warmers and have been imbued with damping qualities that are meant to work with bikes' showroom suspension settings.

The Pros look like the World Superbike-spec slicks but follow the construction and profile of the Diablo Supercorsas. As always, the Pros are based on Pirelli's zero-degree steel-belted construction and have been engineered with more carcass flex than their DOT-approved counterparts to complement the tires' new "high-duration" tread compound. The tires' slick surface provides the biggest footprint possible while also helping them last longer by eliminating tread grooves that can act as starting points for wear when suspension or tire pressures are set improperly.

To get a feel for these tires, I mounted a set on my Triumph Daytona 675 long-term testbike and hit as many track days as time and budget allowed. From full-throttle Willow Springs to bumpy Buttonwillow to the canyon-like Streets of Willow, the Pros provided enough grip to run in the A-group while wearing at a snail's pace. As advertised, they're long-lived. They've shown tremendous heat-cycle stamina, enduring upwards of 50 cycles over the course of 400 track miles with no signs of bluing or hardening. With 4mm of depth left to the wear indicators, there's life left in them yet.

The Pros don't skate and slide the first lap out the way sprint-race tires do, but they still need a lap or more to come up to temperature. The new compound worked well in temperatures from 45 to 85 degrees, but as with all Pirellis the tires are sensitive to pressures. A mere 1-2 psi can make the different between optimum and oops, but the Pros are less susceptible to temperature-induced wear than standard SC2-compound Superbike slicks. You can feel the extra compliance in the front tire when you apply the brakes. The squish slows steering response a bit and is more evident the harder you brake, but that deformation translates to a massive contact patch and excellent traction. The rear tire proved less tacky and 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 its new compound formula and carcass design, Pirelli has successfully negotiated an excellent compromise between durability and grip. Because they're slicks, they're not DOT-approved for street use. But for track-day junkies with dedicated track bikes or those participating in multi-day track events, the Diablo Superbike Pros are a superb choice.

Pirelli Diablo Superbike Pro Slicks
Price: $180 front, $212-$216 rear
Contact: Pirelli Tire North America
www.us.pirelli.com

Verdict 4 out of 5 stars
The perfect amalgamation of race tire grip with street tire warm-up, durability and consistency. Too bad you can't use them on the street!