For its Diablo Rosso tires Pirelli spent fours years in research and design to find the happy medium between street durability and track-inspired performance.
Tires are the intermediary between a fastest lap and a trip to the gravel pit. And with Japan, Italy, England, Germany and now even the U.S. producing 1000cc-plus motorcycles that crank out upwards of 130 horses to the rear wheel, the time has come for a new generation street tire that can handle those mega-power outputs and the associated loads that accompany putting that much power to the pavement.
Tire development is all about compromise. Make a tire too sticky and we'll burn them up in a few hundred miles. Make a tire too hard and we'll get the mileage we desire but sacrifice grip and warm-up time. Integrate numerous tread cuts and it displaces water but compromises our coveted contact patch. We could continue our dissertation on compromise, but
Pirelli believes that it's found the right middle ground with a tire that can meet the needs of both 21st century man and machine.
Pirelli World Superbike engineers have been hard at work for the last four years developing a race rubber that can handle the 200-plus horsepower loads over 90-km race distances. This race track R&D trickles down to the street riding enthusiast in the form of the all-new
Pirelli Diablo Rosso tire.
The Diablo Rosso is the street-oriented sibling in Pirelli's Diablo tire line up. But just because it was developed for the streets doesn't mean that it can't be used on the track. To prove this, the Pirelli crew invited us out to sample its newest tire on a challenging 120-mile street ride that originated in historic Santa Paula, California, and ended at the Streets of Willow in Rosamond, California.
The high points we found with the Pirelli Diablo Rosso tires are its neutral steering, quick warm-up times, phenomenal levels of adhesion, and its overall stability.
In the fashion of Pirelli's World Superbike tires, the Diablo Rosso features a naked shoulder on both sides of the tire. This allows the tire to maintain a complete contact patch with the tarmac when it's rolling at maximum lean angles. Between those tread-less sections lays a new tread pattern that utilizes Pirelli's "Functional Groove Design," that concentrates tread grooves in the middle of the tire where they are needed the most.
Within that cool-looking tread pattern is a new compound that has been specifically engineered for passionate street-riding enthusiasts. Fast warm-up times, consistent levels of grip regardless of weather conditions or road surface, and exceptional tire life are a few of Pirelli's claims that we sought to test during the intro.
Street riders have enough to worry about while navigating the world's mean streets. Pirelli doesn't want you distracted by traction issues so you can concentrate fully on the road. The Diablo Rosso is designed to help riders remain focused with its ability to maintain control even in the most adverse conditions, continuously maximizing the contact patch via its unique tire profile that incorporates Pirelli's patented "Zero Degree" belt design. What is "Zero Degree" belt technology all about? The term refers to the carcass design in which steel belts are laid in the same direction as the rotating tire. This helps prevent the tire from growing or flexing too much when it's being subjected to a hard load.
The Pirelli squad mounted up a set of Diablo Rosso tires (120/70-ZR17 front and 180/55-ZR17 rear) on our 2007 Honda CBR600RR. With the tire pressure set (36 psi front, 42 psi rear), we hit the streets of Ventura County. Once under way, it became immediately clear that the tires do not offer the greatest feel. Throughout the street ride we felt disconnected from the road below. However, steering was extremely neutral and side-to-side direction changes were no better or worse than the OEM Bridgestones that were previously fitted.
The lack of feel from the rubber made it difficult for us to really push hard through the curvy, mountain route that Pirelli had laid out for us. The few times we were able to man up and actually work the tires, they performed flawlessly without a hint of instability or lack of traction. In fact, adhesion levels felt very consistent. During our photo shoot, a few times we locked up the rear wheel to speed up the turn-around process, sliding the bike around 180-degrees. The rear rubber consistently slid, making us look like we actually knew what we were doing.
Normally our CBR600RR delivers a relatively plush ride on the street for a 600cc sportbike. But with the Rosso underneath us, that smooth ride was compromised. The CBR's tires normally work in unison with the suspension to help soak up some of the irregularities and bumps in the pavement, but the Rosso tires have a stiffness to them that translated every bump and pavement ripple directly through the bike.
Attack Kawasaki's Steve Rapp:
"These tires are pretty impressive. These things heat up really fast for street tires."
The high desert near Willow is famous for its smooth, perfectly straight, traffic-less stretches of road that extend as far as the eye can see. Therefore it was an ideal spot to bump it up a notch and test the tires stability at high speed. And we can say this: when speeds reached well into triple digits, the new Pirelli Diablo Rosso offers exceptional balance, even on just one wheel.
Around noon we arrived at Willow's 1.8-mile road course. We were welcomed with sunny skies, mild 70-degree temperatures and very little wind-ideal conditions for a thorough race track evaluation. Before hitting the circuit, we aired down the tires from the street setting to a lower track-oriented setting of 30 psi front and rear.
After an hour-long lunch, we entered the track with completely cold tires. Within a half lap we already had our knee down, which is extremely impressive for any tires, regardless of street or race designation. We weren't the only ones blown away by the tires ability to get us up to speed quickly.
"These tires are pretty impressive," commented Attack Kawasaki's Steve Rapp. "These things heat up really fast for street tires."
In addition to the minimal warm-up time, the Italian-engineered rubber offered astounding levels of grip. The sticky donuts beneath us gave us confidence to push our CBR hard. We continuously came into the corners hard on the front end-even trail braking all the way up to the apex while experiencing zero front-end pushes. Out back the rear meat hardly ever spun up unless we were overzealous with our throttle hand shooting out of the corner.
"I'm really surprised by how far these street tires have come," said the 2007 Pirelli-shod Daytona 200 winner. "It's been a while since I've ridden on street tires, but these things feel really good."
In reinforcing Rapp's positive opinion, Cycle World's Mark Cernicky passed us on the exit of Turn 3. We watched him accelerate hard out of the corner with his rear tire squatting and digging into the asphalt below with minimal if any spin.
Pirelli split us into groups and we were only allowed on track for 20-minutes at a time, but experienced zero greasiness or any telltale signs of tire overheating. In fact, at the end of the day, the tires looked fairly clean without any tears or unusual wear marks that usually accompany extended track use.
Thankfully we didn't have to sample the tires in the wet (besides a quick Bear Grylls- style stream crossing), but a few weeks later we mounted the Diablo Rosso on our friend, Matt Ambroziak's '07 Yamaha YZF-R1. With the recent wet weather in Southern California, he got a chance to test the tires in pavement-soaked conditions and came away impressed.
After a 120-mile trip through the mountainous roadways surrounding the Streets of Willow, Pirelli was kind enough to have a bike for almost every riding style ready and waiting for some serious track time.
"The tires are good in the wet. Unfortunately for me right now my only means of transportation is my bike, so rain or shine, I'm riding. But these new Pirelli's were good. I didn't have any problems whatsoever and could still cruise down the freeway faster than my fogged-up face shield would allow," said the avid street rider.
We were mostly impressed with the Diablo Rosso. For us, the tires did deliver a harsher ride on the street and didn't have as much feel as we'd have liked, but on the track these shortcomings aren't nearly as apparent. What we did really like about the Italian rubber was the neutral steering, insanely quick warm-up times, phenomenal levels of adhesion, and the fantastic overall stability.
Want a taste of Pirelli World Superbike technology on your street ride? Now you can in a whole slew of 17-inch wheel sizes. Pirelli's got you covered, from a 110/70 front to a 190/50 rear and everything in between. What makes them even more attractive is the reasonable price for this race track-engineered technology.
Front tires range from $139.95-156.95, while a new
rear Rosso will run between $185.95-235.95
