Angel GT outstrips rivals’ mileage, says Pirelli

The latest sport touring tyre from Pirelli, the Angel GT, has hit the streets – and the Italian tyre maker claims it is number one for mileage within its segment. This weighty statement is based upon testing carried out by Motorrad TestCenter in Germany. Tyres & Accessories has yet to read the test report, however Pirelli indicates that the Angel GT was certified by Motorrad TestCenter as delivering better mileage than the Michelin Pilot Road 3, Dunlop Sportmax Roadsmart II, Bridgestone Battlax BT 023, Continental RoadAttack2 and Metzeler Roadtec Z8 Interact M/O.

For the test, held in Spain from 27 November to 14 December 2012, a set of 120/70 ZR17 and 180/55 ZR17 tyres were used as the standard and six Suzuki Bandit 1250 ABS bikes were used. The test was conducted on fast roads between Málaga, Algeciras, Jerez, Seville, Cordoba and Antequerra at an average speed of 120km/h and on country and mountain roads with speed limits between 90 and 110km/h between Marbella, Ronda, Algodonales, Ardales, Alora and Málaga.

The test sessions were held in dry weather conditions with rather low temperatures, but consistent throughout the period. As the route travelled through a wide range of altitudes (from 10 metres to 1,100 metres above sea level) the air temperature varied from 5 to 18 degrees Celsius, while the asphalt temperature ranged from 18 to 23 degrees Celsius. “At the end of the test the Angel GT was found to be the tyre with the highest mileage compared to the competitors in the sport touring segment,” states Pirelli.

30% better mileage than predecessor

Pirelli calls the Angel GT the “crowning jewel” of its sport touring range and the “natural descendent” of the Angel ST. Compared with its predecessor, the Angel GT is said to offer 30 per cent improved mileage, one metre shorter braking distance from a speed of 75km/h, improved wet grip and handling, and – something Pirelli considers even more important – the ability to maintain these characteristics at a high level over the tyre’s life cycle. This is a property Pirelli refers to as “Performance Mileage”.

And the ‘GT’ designation in the new sport touring tyre’s name? Pirelli says it adopted the letters as the Angel GT is “100 per cent Italian Gran Turismo”, an “ideal tyre for those riders who travel long distances with a passenger and the bike fully loaded, or who simply take a ride in the country, but also for those who use their bikes all year round, both for recreation and commuting.” The tyre maker says this applies no matter what bike is used, whether a touring bike, a street enduro, naked or sport bike.

Tread design

 The Angel GT tread is described as being a “clear evolution” of the Angel ST tread in technological terms as it was primarily designed to provide reduced and more regular wear and improved water drainage. Pirelli says both the front tyre and the grooved rear tyre guarantee this. To provide optimum wear, the aforementioned grooves were directed following the theory of Schallamach wear waves, which describes the mechanics of a wear crest forming on the tyre depending on the amount and direction of the forces exchanged between the tyre and asphalt at each point of the profile.

The arrangement and direction of the grooves were also studied in order to optimise water drainage; Pirelli shares that they allow a ten per cent reduction in void/fill on the front and 16 per cent reduction on the rear, which translates into a larger area of compound in contact with the ground and therefore better grip and better wear. 

Unlike the Angel ST, the new Angel GT tread does not change its design with use – Pirelli says this is a “testament” to the fact that its performance remains essentially unaltered for the tyre’s entire life cycle.

Profile

 Part of the Pirelli Research and Development centre’s work on increasing mileage involved redesigning tyre profile for the Angel GT. Pirelli says the new tyre’s profile is based on a variable radius curvature design; it says the central radius was increased by about 35 per cent in order to create a less rounded central section. This way, both the size and the proportion of the ground contact area were significantly modified and is now six per cent shorter and 15 per cent wider than the Angel ST contact area. 

Generally speaking, compound wear is caused by the sliding that occurs when the compound exits the surface area as the tyre rolls. This is why the size and shape of the contact area has a direct impact on compound wear. Pirelli explains that a shorter contact area means less overheating, less sliding and therefore less compound wear. At the same time, a 15 per cent increase in width means a better distribution of wear over a larger portion of tread, providing for superior performance and more regular wear. By combining this technical solution with a specifically designed compound, Pirelli engineers claim they were able to increase the mileage of the Angel GT by about 30 per cent compared to the Angel ST.

Structure

 Underneath the tread and profile lurks a new rayon casing; Pirelli says its development stems directly from the know-how it has acquired in racing, particularly in the FIM World Superbike Championship. The new casing has 32 per cent more linear density, with 60 per cent higher rigidity compared to the Angel ST, and at the same time Pirelli says it allows for an agile and direct ride, high push and grip in turns and excellent damping capacity on bumpy asphalt. The tyre maker adds that it also guarantees the initial performance of the new tyre will stay consistent for the entire life of the product.

Compounds

 Pirelli says the aforementioned qualities enabled its engineers to “decisively rethink” the choice of compounds used in the Angel GT and how they are applied, and in doing so solutions were found to previously difficult technical issues. The rear tyre features a dual blend compound with ‘cap&base’ technology – a technology that provides grip in the region of the tyre in contact with the asphalt while offering stability through the compound layer beneath this. The front tyre contains a 100 per cent silica formula derived from the compound used on the shoulders of the rear tyre in order to provide similar performance, especially in leans and on wet roads. 

The central section of the rear tyre is around 45 millimetres wide (sizes vary slightly depending on tyre size) and is at least 50 per cent silica, with the remainder carbon black. This formulation is intended to ensure high stability at any level of load and use, greater resistance to abrasion and a high level of grip during acceleration and braking on wet roads. The shoulder compound, which is similar to the compound used on the front tyre, is 100 per cent silica; Pirelli says it is capable of providing excellent grip on dry and wet surfaces thanks in part to the use of controlled microstructure polymers that improve filler dispersion and interaction between the polymers themselves and filler. 

Personalisation

 As is the case with certain other Pirelli motorcycle tyres, the Angel GT sidewall can be personalised. Using an online tool, tyre purchasers can personalise a label by choosing from various fonts, colours, flags, the layouts of famous international circuits and many other logos.  

The Angel GT is already available in the following sizes:

Front

120/60 ZR 17 M/C (55W) TL

120/70 ZR 17 M/C (58W) TL

110/80 ZR 18 M/C (58W) TL

120/70 ZR 18 M/C (59W) TL

Rear

150/70 ZR 17 M/C (69W) TL

160/60 ZR 17 M/C (69W) TL

170/60 ZR 17 M/C (72W) TL

180/55 ZR 17 M/C (73W) TL

180/55 ZR 17 M/C (73W) TL 

190/50 ZR 17 M/C (73W) TL

190/50 ZR 17 M/C (73W) TL 

190/55 ZR 17 M/C (75W) TL

190/55 ZR 17 M/C (75W) TL 

190/55 ZR 17 M/C (75W) TL 

160/60 ZR 18 M/C (70W) TL