For you confussed Pirelli Rosso fans, read below!
MD Product Evaluation: Pirelli Diablo Rosso
By Willy Ivins
Photos by Kevin Wing and Andrea Wilson
Santa Paula, California, the site of Pirelli's unveiling of its latest update to its staple product, the Diablo is a quiet town just about 17 miles southeast of Ojai. It is 1 ½ hour ride from the fastest road in the west, Willow Springs Raceway, where I spent the day getting reacquainted with my 125 GP bike.
Sore and tired (but smiling), I bring my street bike to a stop in the back parking lot of the quaint Inn that Pirelli has arranged for the invited press to stay at, where a waiting Pirelli crew whisks away my bike to install its new shoes, the new Diablo Rosso. Some liquids, a shower and I am refreshed in time for the tech briefing of the tire I'll be riding tomorrow.
From a sales and marketing perspective, the Rosso is a very important product for Pirelli. Aimed at no particular segment, it is designed with supersport (e.g., 600s and 1000s), sport-touring, UJM (think Suzuki Bandit), and supermoto bikes in mind. That said, the supersport class carries significant sales weight in the overall design/development picture. Pirelli has enjoyed double-digit sales improvement in previous years and claims an 87% increase in 2007 alone, so the importance of this tire becomes quite clear.
A 5-year development cycle has brought the Rosso to fruition, with careful attention being paid to the evolution of the bikes we ride. Greater power and torque, lighter weight (up until last year) coupled with more rigid chassis and slipper clutches had placed different and unique demands on a tire.
To tell us about their new pride and joy, Pirelli had not only their North American contingent, but also the Italian engineers who are responsible for the Rosso's performance. They are a passionate bunch who cover the miles and drag their knees through the corners just as we do.
The foundation of Pirelli's development of the Rosso is a trio of acronyms, including Enhanced Patch Technology (EPT), coordinated with Functional Groove Design (FGD), and Ideal Contour Shaping (ICS), the latter being developed for the original Diablo that uses both computer simulations and test rider feedback.
What's different? Plenty. Let's start with the tread pattern. Markedly different in appearance to the Diablo, the pattern is a result of what Pirelli calls "Functional Groove Design", which puts grooves where they'd be most useful in the rain - for the all-weather riders out there, and fewer where the tire can deliver maximum traction when the roads are dry. The front tire has the duty of clearing a dry(ish) line in the wet, and so has more grooves overall, which reach the edge for the wet stuff. Looking at the back tire, the land/sea ratio is noticeably higher with a solid rubber edge telling the observer that Pirelli is looking to get as much rubber to the road when it counts most - when you're on the edge.
Under that tread pattern is a zero-degree steel belt to help maintain proper profile shape, elasticity for progressive feedback and stability under hard braking. The tire structure is also designed to ensure that the front and rear tires work together in a balanced manner.
Rubber compounds are new, and unique in regards to front and rear applications. The rear tire has a balance of rigidity and hysteresis - the flex of the rubber that allows it to conform to the texture of the pavement - for both high and low temperatures for a fast warmup and a linear grip response. Silica black, carbon and high mechanical resistance chemicals combine to create a tire that has strong traction, even wear and exceptional traction in the wet. The front tire has higher hysteresis materials with a high energy dissipation factor (good bump absorption) for more grip and high braking stability. Silica and carbon black make their appearance here as well for wet weather grip.
Another issue concerning wear rates was addressed by the Rosso design team. Typically, a front tire will handily outlast the rear tire, forcing the rider into a dilemma of whether to fit a new rear tire with a partially worn front, or spring for a new front tire to replace it as well. Pirelli says that the front and rear Rossos should wear relatively evenly. Does this mean the front wears more quickly? Actually, no. The rear tire is intended to last more like the front tire, which is good news.
After the technical presentation, we were whisked off to Ventura for a tasty dinner. During the 30 minute ride, it became known to me that we were accompanied by Steve Rapp, 2007 Daytona 200 winner (on Pirelli, naturally), his crew chief and Attack Kawasaki team owner Richard Stanboli, Chris Kilmore, the DJ (or turntablelist) of Incubus and Chris Heese, the drummer of Hoobastank. Pirelli has a marquee following, or the lure of free food, tires and a track day was too much for them (Steve Rapp excluded) to resist! Okay, I admit, I went for the tires and track day"¦"¦"¦
