A growing number of motorcyclists are mounting sport-touring radials on their sportbikes, naked standards, sport-touring, and adventure bikes, as the pool of these bikes with 17″ and 18″ tire sizes continue to grow. Pirelli’s first sport-touring tire, Angel ST (reviewed Oct 2010) maintains its place in the category, providing a good “starting point” in the development of the new Pirelli Angel GT. However, every aspect of the Angel GT has been redesigned in an effort to create a longer-lasting sport-touring radial that improves on the ST’s outstanding wet and dry traction qualities and to keep the tire’s performance throughout its lifespan. This includes the chemical compound and production process, profile shape, and tread pattern. The end result is a top-quality, sport-touring tire that outperforms its competitors in both wet and dry conditions, all the while achieving almost 30 percent more mileage than the Angel ST.
The engineering behind the GT is impressive; Pirelli reps broke it down for the press in first-class style aboard Italy’s Navy flagship aircraft carrier, Cavour, docked in Taranto, Italy. Viewing the presentation in a briefing room onboard, I scanned for Maverick and Goose, but instead spotted Italian motorcycle racing legend (and handsome devil!) Giacomo Agostini sitting in the front row. Wow!
The GT’s tread pattern looks similar to the Angel ST’s, but is simpler and more efficient with optimized, continuous grooves that offer better flow continuity that disperses water away from the contact area. First in line, the front tire grooves are positioned to direct water outward before the center of the rear tire makes contact with the same section of pavement. The center patch offers improved braking in the front and more mileage in the rear. Reduced groove depth on the sides also provides more contact area and better traction when leaned.
The GT’s profile is rounded compared to the ST’s triangular shape, offering more contact patch area, increased lean angle, and smoother turn-ins. Another benefit of the new shape is that there’s less sliding, which ultimately produces wear. The GT’s bigger, shorter, wider contact area when riding straight up makes a 14 percent footprint width increase over the ST’s, causing there to be less stress on the compound, better high-speed stability, and reduced temperature and wear. The footprint of the contact patch during leaning also shows less stress on the compound, plus an extra 5 percent lean angle is available.
The front Angel GT uses a 100 percent silica monocompound for optimal grip and braking characteristics while the rear has a dual compound with 100 percent silica on the shoulder and 70 percent on the center strip. New materials and resins have been introduced with this tire as well as a mixing process that keeps the compounds from repeated heating and cooling during production for a more stable end result. This translates into a quick tire warm-up and consistent performance levels, even while hot.
We convened on the Cavour’s flight deck for the “wet braking test.” Speeding down the wet deck on a Kawasaki Ninja 1000 at 60 mph, I stopped as quickly as the ABS would allow. I got some pretty cool photos for my scrapbook, but testing tires on the flight deck of a carrier resembles no real-life application. The surface can stop fighter planes, after all, and even Pirelli admitted that it had a much higher coefficient of adhesion compared to an average road.
The following day was the true test when we rode at Porsche’s Nardo Technical Center. The 3.7-mile course was designed with real-world conditions in mind. With uneven pavement, decreasing radius turns, and mixed asphalt surfaces, the track mimics actual roads. I rode the track on an FJR1300, Ninja 1000, FZ8, and a Speed Triple.
The tires warmed up quicker than I did in my barely used leather suit. Lightning-fast stops and starts were fun and confidence-inspiring, since the GTs gripped the pavement well. The tires held their ground at extreme lean angles and speed. I never experienced a moment of slippage, even when throttling hard out of the turns. I noted that the GT turn-ins required a little more labor than the ST’s.
Testing the tires’ mileage capabilities wasn’t in the cards on the two-day trip. But Pirelli contracted an independent third party to perform several tests. Up against its top competitors (Michelin Pilot Road 3, Bridgestone BT023, Dunlop Sportmax Roadsmart II, and Conti Road Attack 2), the Angel GT received the best scores for handling and mileage as well as the shortest wet braking distance. The Angel GT is an excellent tire choice for the rider who wants sporty performance but doesn’t want to wear them out too quickly.
By Tricia Szulewski
Pirelli Angel GT
Front from $191; Rear from $210
Originally published in RoadBike August 2013