Tire technology plays a critical role in motor racing. It seems an obvious point to make, but events at this weekend's opening round of the 2013 Supersport season at Australia’s picturesque Phillip Island track hammer home just how important – and how challenging – it is to get the rubber right.
Due to a combination of factors resulting in unusual tire wear, and in some cases tire failure with blistering and chunks of tread coming away from the carcass, Sunday’s race was reduced to 15 laps in the interest of keeping bikes and riders intact for the weekend.
This comes after a similar situation in the opening round of the 2012 season where the Supersport race was also reduced to 15 laps because of tire problems. These have been the only two instances that races have had to be shortened for last minute technical reasons since the Supersport category’s inclusion into the WSBK series in 1997, but it’s not for the want of learning from one’s mistakes – this time there are totally new circumstances.
As explained by Pirelli representative, Matteo Giusti, the tires supplied for the meeting were unsuited to the conditions when it was discovered, in test rides only days before the opening round of the 2013 season, that the new surface on the Phillip Island track was harder on the tires than anyone had anticipated.
“We shipped the tires out for this opening round last year, by boat, before the resurfacing had been completed so we were not able to understand fully the conditions to which they would be subjected.”
It is a different situation in many ways in this, the first round of the 2013 WSBK world championship season: new 17” tires (changed from 16.5” in previous seasons), new teams, new bikes and at Phillip Island, a new track surface. So trying to get everything right with so many unknowns is almost impossible, even for Pirelli, which also has the supplier contract for F1.
Although the new track surface is proving to be more abrasive and harder on the racing compound than anticipated, it's still very fast. All the track records were smashed on the weekend, and all the tires ended up lasting the revised race distance, so the riders are enjoying the extra speed they are getting.
It may appear to a racing fan or casual observer that tire failures are a simple case of inferior products or manufacturing limitations, but the variables involved are so many and so finely attuned that there are never simple solutions to choosing the right compound for the day.
Different tires are engineered for different tracks but also factoring in the weather and track temperature are just the beginning of working out which model of tire each team chooses for their riders from the narrow selection supplied by Pirelli.
At Phillip Island, for example, the left hand side of the tire is subjected to much more wear due to the long, fast left hand turns and, if the temperature gets too hot on the track, then the forces on the tire carcass and tread compound become too great and things start to fall apart, or if you’re on a bike, off. And that’s what nobody wants.
Apart from the obvious conditions to affect tire choice such as the weather – wet or dry, hot or cool – even the direction of the wind at Phillip Island plays a part in tire wear. If it’s a southerly off the water, it’s OK, but if it’s from the north, it carries tiny amounts of dust and sand onto the track which further increases its abrasive nature which, in turn, causes more wear and higher working temperatures. A subtle difference, one would assume, but in racing conditions that rely on tenths of seconds per lap to be the difference between winning and coming nowhere, it matters. And it’s another headache for the Pirelli engineers and team chief mechanics.
Phillip Island has also had its fair share of problems when it comes to WSBK. In 2001 it rained so heavily that the inside of some of the corners disappeared under water and Troy Corser famously stood at the exit to the pits frantically waving to stop his fellow riders from going onto the track before the second WSBK race was officially cancelled, only the second time this had ever been done since the series’ inception in 1988.