Since this is the first time the eni FIM World Superbike Championship will be held at Portimão in the month of June, Pirelli will be bringing various solutions, some of which were already used at Phillip Island and Monza, in SC0 and SC1 compounds which best adapt to operating in the heat

With one third of the eni FIM World Superbike Championships behind us now, Pirelli is ready to get back on the track in Portugal at the Autódromo Internacional do Algarve, where there was a Superbike round just 8 months ago, for the sixth round of the 2013 season.

Up to now the 17 inch tyres which have been used from this season in the Superbike class as well have performed very well, confirming the expectations of both the Milan-based company’s designers and the riders who have consistently improved their lap times and even broken historic records.

Pirelli’s development work continues in any case throughout the year, not only to provide the riders with better and better solutions, but also because, staying true to the “We sell what we race, we race what we sell” philosophy, at the end of the season any compound solutions which have proven to be better than the standard ones will be added to the range next year in order to provide bikers with tyres that are always up to date in terms of technology and performance.

At Portimão, after the Donington absence, the smaller Superstock classes will be back in action for their fourth round.

The Portuguese track which will be the setting for the 4 eni FIM World Superbike Championship classes was designed by architect Ricardo Pina and is 4592 metres long with turn radii that go from a minimum of 23 metres to a maximum of 207 metres. The straight line to the finish is 835 metres long and the rider in pole position starts from the right side of the track.

Portimão from a tyre point of view:

Since being opened in 2008, the asphalt on the Portuguese circuit has gradually lost its aggressive character, greatly smoothing out its harshness on the tyres and losing some of its natural grip. When it hosted the first official competition on 2 November 2008 with the final round of that season’s World Superbike Championship, ending with the farewell to multiple world champion Troy Bayliss, tyres with extremely high mechanical resistance had to be used in order to prevent tearing of the tread surface and to minimise removal of the compound due to friction. The situation last year was quite different when even the softest solutions suffered in terms of grip with the asphalt temperature above 40°C. This year, since the races will be held in June, the temperatures may very well be even higher and this effect could be even greater.

Generally the Autódromo Internacional do Algarve is one of the circuits that best bring out the capacity of the tyre to operate in extremely different conditions.

The part of the track that puts the tyres to the hardest test is the last turn which is 350 metres long and takes 6.5 seconds to navigate: due to the large turn radius (about 150 metres), the bike is in constant acceleration and goes from 150 to 250 kph at a lean angle of about 50°. This causes a significant increase in temperature on the side of the tyre affected by the lean, particularly for the rear tyre which must withstand the high heat while simultaneously ensuring strong lateral force and allowing the bike to accelerate. Therefore, with high running times and fixed lean angles (especially in the event of low grip) high spinning is generated as well as significant peaks in localised temperature at 45-50°C on the tyre shoulder. The weakening of the compound due to heat, even with smoother asphalt, causes significant levels of material removal. For this reason a significant amount of tyre wear can often by noted at the end of the races. The riders who are able to come out of this turn and onto the straight stretch at the highest speed will be able to gain a significant advantage over their rivals.

On the contrary, turns 5, 8, 11, 13 and 14 have a very tight radius (about 30 metres), which forces the rider to brake to an extremely low speed. Halfway through the turn the bike needs the rear tyre, which is very cold, to provide strong longitudinal acceleration up to 1G at a lean angle of 50°. The tyres are particularly cold, especially coming into the left handers (numbers 5 and 13). Once again, the riders who are able to accelerate a bit earlier than the others will have an important advantage.

While the rear tyre must go from low to extremely high temperatures, the front one has other, just as important, tasks to complete. It must be able to come into the turns mentioned above quickly and precisely. At the end of the straight stretch over the finish line, in other words, the first turn with the 100 metre radius which allows the riders to hold speeds greater than 100 kph, the front tyre is particularly stressed because it has to travel about 80 metres at a lean and with the rider on the brakes.

Taking the pre-summer heat into consideration, it will be very important to balance out these aspects when selecting the rear tyre: compound grip, wear resistance, elasticity of the tyre in the heat (to prevent de-compaction effects), movement in running and loss of support.

Speaking of this, for the Superbike class rear a new version of the SC0 range (S502) with the same compound will come alongside the standard version. This new version has higher thermal resistance and stability at higher temperatures.

Should the softer compound have problems with wear, two SC1 solutions will be available, both developed to improve thermal resistance and heat dissipation. These latter two solutions were already used at Phillip Island and Monza, where thermal resistance must be as high as possible.

Unlike the rear, which must handle little, but intense, mechanical/thermal stress, the front is constantly used in slow turns and turns with quick entry and small curvature radii. This forces the rider to brake sharply, even going downhill. Generally wear problems are not an issue on the front tyres, so often high grip (SC1) solutions are used. However, the important aspect to consider is how the front withstands the heat (a must for good precision), particularly when coming into the first turn.

If necessary another two compound variations of increasing solidity will be available in addition to the SC2 solution in order to cover the needs of the riders in the harshest braking situations as well.

Portimão from a technical point of view:

“This will be the first year racing on this track during the month of June and this obviously constitutes an unknown that should not be underestimated” Pirelli Moto Racing Director, Giorgio Barbier points out “because we may encounter quite high temperatures that we are not accustomed to and this could be a problem for the tyres, causing them to blister. Of course we have taken the necessary precautions and we will provide the riders with some development solutions in addition to the standard ones, both new and some already successfully used at Phillip Island and Monza. In fact, in addition to aiming toward constantly improving performance, our goal is also to always be able to provide the riders with a solution which will at least allow them to finish the race even in the most extreme conditions. That said, Portimão is still one of the nicest and most spectacular tracks in the World Superbike Championship with its up and downhill sections and its blind turns, so I am sure we will see some great races”.

Pirelli solutions for the Superbike and Supersport classes:

For the sixth round of the eni FIM World Superbike Championship Pirelli will be brining 4636 tyres to Portimão, a quantity capable of covering the needs of all four classes taking part in the Championship. Specifically, there will be 1630 tyres for the Superbike riders, 2016 for Supersport, 480 for Superstock 1000 and 510 for Superstock 600. Each Superbike rider will have 38 front and 40 rear tyres to choose from, whereas the Supersport riders will have 30 front and 26 rear tyres.

The riders in the top Superbike class will be able to count on 4 slick solutions for the front and 4 for the rear, in addition to a quantity of 2 per rider of the rear qualifier and the intermediate solutions, 4 for the front and as many for the rear, as well as 8 wet tyres for the front and 8 for the rear.

On the front the standard SC1 (R426) in soft compound (already brought to the first five rounds and ideal for low external temperatures and/or medium harsh tracks) will be joined by 3 SC2 compound solutions: the R982, which is the standard SC2 which has been brought to all the rounds this year, excellent for high external temperatures because it guarantees a solid tread, the R1220, a development solutions that was already brought to both Phillip Island and Monza and the alternative to the standard SC2 solution which is a bit less robust and the R753, another development solution in alternative to the standard SC2, also brought to Phillip Island and Monza, even more robust than the R1220 and therefore better able to withstand the aggressive nature of the asphalt and more suited for riders who are hard on the brakes.

On the rear there will be two SC0 and two SC1 solutions. After the satisfaction it provided the riders at Monza and Donington, the standard SC0, (R1261) is confirmed as one of the best options in case of high temperatures. In fact, it is ideal for tackling smooth asphalt and high temperatures because it provides maximum contact area on smooth asphalt and maximum traction development at high temperatures, in addition to its greater performance stability under thermal decline. As an alternative to the standard tyre the riders will be able to opt for the S502, an SC0 development in soft compound that should guarantee greater performance stability, especially in the event of high temperatures. On the other hand, the SC1 are both development solutions: the R1255, a medium blend that was already brought to Phillip Island, should be more robust and consistent than the standard solutions usually used and capable of better dissipating the heat. The S514, which made its début at Monza, uses the same compound as the standard SC1 solution but it has a reinforced central strip and was designed with different internal materials in order to maintain particularly low operating temperatures. At Portimão, precisely because of the probability of high temperatures which could cause blistering, the same Superpole tyre (S516) with a reinforced central section compound already used in Monza will be present.

For the Supersport class there will be two standard solutions available for the front, the soft blend SC1 (P1177) and the medium compound SC2 (R1031) already used and brought to all the races so far in 2013. These will be joined by a new development solution, the S753, which falls about midway between the SC1 and SC2 in terms of compound hardness, providing more stability and rigidity than the SC1, but better grip than the SC2.

For the rear in the Supersport class as well there will be two SC0 development solutions available: the S510, ideal in cases of high temperature and already used at Monza, and the S523, a new option that uses the same compound as the S510 but works better when temperatures are particularly high. The standard SC1 solution (R303) joins these two solutions, already brought to all the rounds raced this year.

The 2012 Pirelli statistics for Portimão:

• Total number of tyres Pirelli brought: 4804

• Number of solutions (dry, intermediate, wet and qualifier only for rear) for the Superbike class: 5 front and 8 rear

• Number of solutions for the Supersport class (dry, intermediate and wet): 4 front and 5 rear

Number of tyres available for each Superbike rider: 34 front and 35 rear

• Number of tyres available for each Supersport rider: 24 front and 29 rear

• Superbike Best Lap Awards won by Carlos Checa (Althea Racing) in 1’56.477 (Race 1, 16th lap) and Eugene Laverty (Aprilia Racing Team) in 1’44.578 (Race 2, 5th lap)

• Supersport Best Lap Awards won by: Jules Cluzel (PTR Honda) in 1’47.416 (6th lap)

• Temperature in Race 1: air 21° C, asphalt 22° C

• Temperature in Race 2: air 25° C, asphalt 32° C

• Maximum race speed reached by Pirelli tyres: 302.5 km/h, Max Biaggi (Aprilia Racing Team) in Race 2 on the 17th lap.