Though extremely hot conditions created greasy conditions for Catalunya MotoGP last weekend, Yamaha Factory Racing’s Jorge Lorenzo rode with complete precision.
The Spaniard, who started from third on the grid, got to turn one first and led all 25 laps of the Catalunya Grand Prix. Lorenzo was joined on the podium by the Repsol Honda duo of Dani Pedrosa and Marc Marquez, respectively.
En route to taking his third win of 2013 MotoGP, Lorenzo tested the very limits of the Bridgstone tires.
Following is a Q&A with Shinji Aoki, the Manager of Bridgestone Motorsport Tire Development Department.
Q. Montmeló experienced very hot temperatures last Sunday. What affect did this have on tyre performance and race tyre choice?
Shinji Aoki says: “Indeed, the whole of the race weekend saw very high track temperatures with peak recordings reaching almost 60°C. The Wednesday before the race we modified our tire allocation for the race to provide our two hardest compound front slicks as we knew conditions were going to be extremely harsh on tires.
“The very high temperatures affected tire performance by making the track quite greasy and also increasing tyre wear. Over short runs, we could see that outright tire performance was very good, with Dani setting a new circuit best lap time in qualifying. The race pace was also better than last year, but we did see that over race distances that tyre performance was compromised somewhat by the extreme heat.
“The scorching conditions ultimately didn’t affect race tire choice greatly, rather tire choice revolved around choosing options that best suited the characteristics of the circuit where the riders spend a lot of time at large lean angles.
“As a result, all but one rider selected the hard compound front slick, as this specification offers greater cornering stability, with the bonus of greater durability. This same factor of the riders spending a lot of times banked over in the corners was also why most riders preferred the softer rear slick option, as they want the highest level of grip from the edge of the rear tyre when they are leaned over in corners.”
Q. With such high temperatures on race day, were you surprised that no riders selected the hard compound rear slick option?
Shinji Aoki says: “We did expect that in the very hot conditions that some works riders would select the harder rear option, but this didn’t happen so we can’t say if this option would have performed better over the race distance.
“We did see many riders evaluate the hard compound rear slick earlier in the race weekend, often at a competitive race pace, but come the race all the works riders went for the softer option. The riders always want as much grip as possible from the edge of the rear tire as they feel that having good pace at the beginning of the race is very important for the race result. With this in mind, they will use the softest slick available and find a way to manage it effectively over the race distance.
“This is a trend that is quite noticeable this year; that even in very hot conditions riders are working hard during the practice sessions to find a way to make the softer rear slick work for the race. What is obvious is that progress in electronic management systems, motorcycle setup, and the riding style of the riders has evolved to a point that riders can effectively use softer rear tires in almost any scenario.
“If they can manage the durability of the soft compound, there is no reason to use the hard compound. As a result we are now developing experimental rear slicks to see if we can broaden the effective operating range of our hard compound slick tires.”
Q. What development is Bridgestone undertaking to create a new hard compound rear slick tire that will be more desirable for the riders?
Shinji Aoki says: “Our MotoGP tire development program is constantly developing new experimental tires, and at the post-race test at Montmeló on Monday we tested a new hard compound rear tyre. The rider feedback regarding this latest evolution of tyre is that it is a big step in the right direction, so we will continue working down this development path.
“We are also considering other technological developments in regards to the rubber compounds of our rear slick tires that we plan on providing for testing purposes later this year. Once we get a general consensus from riders on what works best, we can then consider introducing a new hard rear slick option into our tire allocation.
“In the meantime, we will work closely with Dorna and the FIM to see how we can best use our current range of tires to ensure all the riders on the grid have a tire allocation that works best for each circuit.”
Bridgestone slick compounds available:
Front: Medium & Hard. Rear: Soft, Medium & Hard (Asymmetric)
Bridgestone wet tire compounds available: Hard (Main), Soft (Alternative)