Pirelli Angel ST Tire Review

A grippy tire with slick marketing

story by Pete Brissette, Photograph by Tom Riles, Created Sep. 24, 2009
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Pirelli has launched yet another tire, the Angel ST. The new buns first arrived for Europe in the spring of this year, and have now finally made their way stateside.

Like a lot of things, be it a product or a person, with origins in Italy, the new tire is born of “passion.” But current economic forces these days have influenced the tire’s design and performance goals.

So, a tire designed around the sport (passion) side of riding, must then also give an equal amount of consideration to the practical side (good mileage, comfort, etc) if it means to grab the attention of today’s price-conscious motorcyclists. You could say that a tire need have more than one dimension to its “soul.”

Pirelli’s latest tire, the Angel ST, isn’t just for the touring-minded set. The new tire offered plenty of grip and handling performance, making it a good choice for sporty, hooligan machines like the Triumph Speed Triple.

Fee-fi-fo-fum, I smell some Pirelli marketing-um!

The Angel ST has been named in homage to the Angels and Demon film – based on the novel of the same name from author Dan Brown – in which Pirelli was a partner. Movie tie-in aside, I have to admit I like the creative marketing of the Angel ST.

The idea that a tire can have both a practical (angelic), long-wearing tread life with stability as a key feature, and also pander to that devilish part in many riders that demands a tire have excellent cornering grip in both dry and wet conditions when wicking it up in the turns, is a fresh twist on the do-it-all-tire premise.

The image of an angel is embossed, for lack of a better term, on part of the center tread. Er…okay? An angel in the tread? Check out detailed images of the angel in the Angel on Pirelli’s Angel ST website.

A bit silly, but again also unique and kinda cool. Don’t like it? Then complain to the Design School of Milan. The school assisted Pirelli with the Angel’s design by taking inspiration from “wing” shapes of angels and demons as a starting point for the tread’s aesthetic appeal.

According to Pirelli, after approximately 650 miles this angelic image wears away, leaving the true tread pattern in place, creating a demonic image when viewed with the proper mentality. The tread that remains after that fateful 650-mile mark offers reduced land-sea ratio when compared to the Diablo Strada that the Angel replaces.

An angel riding pillion? Nope, just the Angel ST tire providing lots of lean angle, even in damp conditions along the Blue Ridge Parkway.

An Angel on their side: Pirelli sets FIM 24-Hour Records

To give the new Angel ST a thorough flogging, and chase down a gaggle of FIM endurance records in the process, Pirelli went to extremes.

In the spring of this year the Italian tire company spooned the new Angel ST tires on a Suzuki Hayabusa and Kawasaki Concours 14, – only one set per bike. Fifteen motorjournalists were gathered along with 12 Pirelli test riders to pilot the pair of land rockets around the 7.8-mile circular test track in Nardo, Italy.

Twenty-four hours and 3,190.8 miles later, having averaged 132.9 mph, a new FIM duration record was set for a production bike in the 1,000 – 1,350cc class.

Using some complicated (at least to me) mathematical computations, Pirelli calculated that the nearly 3,200-mile distance at that ludicrous speed was equivalent to roughly 7,500 miles at real-world speeds.

The poor Connie competing in the 1,350 – 2,000cc class gave up the ghost near the end. The unfortunate bloke riding the big Kawi at the time of its meltdown had to push it, unassisted, the last several kilometers in order for the records it set to be legal, so-to-speak.

After a long, lonely walk to the finish, the combined efforts of all involved still managed to nab six new records for the class, all on one pair of Angel ST tires.

Side-to-side tread design on the front tire is different than the rear. Front tread aids water dispersion for the rear tire, while at the same time the front’s shorter tread groves minimize tread movement in order to increase stability and improve braking performance. Pirelli states that rear tread design emphasizes water drainage at “every angle.”

What seemed most impressive from Pirelli’s claims about the tread and profile of the Angel ST is that tread groves allegedly retain all their handling, grip and drainage performance throughout the life of the tire, rather than see these qualities diminish as the tire wears.

Raining or not, riding in Western North Carolina is awesome!Instead of fancy multiple compounds, or cutting-edge steel-belt design (though it does employ Pirelli’s patented zero-degree steel-belt design, but with less steel for a lighter tire), the Angel ST relies primarily on tread design and improved tire compound composition for its all-encompassing performance.

High silica content enhances tire stiffness for increased mileage and stability, while at the same time improving wet grip. And a new cocktail of various resins and carbon black, in addition to the high silica content, improves dry grip and ride comfort.

Compared to the Diablo Strada, the Angel ST purportedly offers 3% greater lean angle, 9% better braking performance (10.7 feet less distance to stop from 50 mph when compared to the “competition”) and 8% better grip and stability performance in corner exits. The Angel partly achieves these improvements by way of what Pirelli calls Enhanced Patch Technology.

EPT, as it’s referred to, is designed to optimize contact patch width, and was first developed in Pirelli’s race tires, eventually making it into the high-performance Diablo Rosso street tire, and now into the Angel ST.

Proof is in the (very wet!) puddin’

Rarely during a street tire introduction do we get the chance to evaluate a tire’s wet weather performance. As it turned out, a late summer storm cell moved into the Asheville, NC, area at exactly the right time. What would normally be miserable conditions for riding turned out to be the ideal setting to see just how well the Angel ST lived up to the hype.

Ideal conditions? Unfortunately, yes.Two days of riding had us tooling through the lush green countryside, enjoying some of the best undulating, twisty-turny two-laners outside of So Cal I’ve ever ridden. Day one saw scattered rain, so we had plenty of dry tarmac as well as damp conditions, while the second day’s route was shortened due to continual rainfall. Perfect!

Triumph Motorcycles America provided a fleet of test bikes. The Speed Triple, Tiger and Sprint ST – and the grunty in-line 1,050cc Triple that powers them – made for excellent machines with which to survey the Angel ST’s sporting side as well as its kinder, gentler nature.

Though I spent the majority of my time aboard the Sprint, a few extended rides on the roughneck Speed Triple revealed that the Angel performs for the peg dragging rider as well as it does the touring rider.

Good grip was available almost immediately, as the Angel only needed limited time to come up to temperature. But what impressed me most about the tire – especially while aboard the Sprint ST – was its smooth, linear steering feel, as well as great bump compliance, overall comfort, and good front-end feedback. I also was pleased with how stable the bike(s) were during freeway speeds.

Equally noteworthy were the buns’ performance under heavy braking – even in the rain! All-fingers-force applied to the brake lever for a rapid but controlled stop never resulted in any tire hop or ABS activation (on the Sprint), just predictable feel from the tires.

The true test of the Angel, though, came on the second day when over two hours of riding in the rain would expose any serious shortcomings in the new Pirellis.

Even the shallow puddles that can form in the outer edges of the roadway lanes couldn’t phase the Angel ST. Water was funneled away just as advertised, giving me the confidence to ride as quick as I dare in the wet.

Note how well the rear tire directs water away, even while at lean.

Only one time during the deluge did the tires seem to squirm during some moderate lean angle. However, in fairness to the tire, this only happened on one particular section of road, a road that looked as though it may have been resurfaced in the previous 12 months (read: slippery!). Otherwise, the tires were flawless during a couple hundred miles over various surfaces.

Rather than damn the tires for protesting a little bit on that particular road, what I took away from the experience was more important than what may have been the lack of ultimate grip: Both tires provided excellent feedback, informing me of just how little grip may have been available.

In what proved to be more impeccable timing on this journey was the chance to ride the one Kawasaki Concours 14 that was available. Recalling the Connie’s sluggish steering we experienced during our 2009 Sport Touring Shootout, I’m pleased to say the Angel cured the Kawi of most of its heavy steering effort that we speculated at the time may have been the result of the bike’s stock Bridgestone Battlax BT021 tires.

According to Pirelli Tire V.P., Scott Griffin, the Angel ST is currently the only non-OEM tire fitment Kawasaki approves for the Concours.

The new Angel ST appears to be one of the best options available in the market for sporty, and sport-touring motorcycles. And, perhaps best of all, you get performance improved over the Diablo Strada, yet pricing for the Angel will be the same as the Strada.

The new Angel ST tire is an excellent choice for an excellent sport-tourer like Triumph’s Sprint ST.

Sizes currently available are 120/60 and 120/70 x 17 for the front, with MSRP starting at $171.95. Rear sizes available now for 17-inch wheels are 160/60, 180/55 and 190/50, with MSRP starting at $211.95. Pricing for additional sizes will be available in 2010.

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Metzeler Roadtec Z6 Interact Tire Review
Pirelli Night Dragon Tire Review
Pirelli Diablo Rosso Tire Review
Pirelli Night Dragon Tire Tour of North America
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