Bridgestone Press Release: Shinji Aoki Explains Why Asymmetric Front Tires May Not Have Helped At The Sachsenring
Bridgestone today issued their usual post-race debrief discussing how their tires held up at the last Grand Prix, this time at the Sachsenring. There was much controversy at the German racetrack over the number of crashes, with riders responding positively to media suggestions that an asymmetric front tire may help. Bridgestone's Motorsport Tyre Development Manager Shinji Aoki addresses this, and other questions in the press release.
German MotoGP™ debrief with Shinji Aoki
Wednesday 17 July 2013
Bridgestone slick compounds available: Front: Soft & Hard. Rear: Soft, Medium & Hard (Asymmetric)
Bridgestone wet tyre compounds available: Soft (Main), Hard (Alternative)
Repsol Honda’s Marc Marquez won his second race of the season at Sachsenring after overcoming the challenges of Monster Yamaha Tech3’s Cal Crutchlow and Yamaha Factory Racing’s Valentino Rossi who placed in second and third place respectively.
Weather conditions at Sachsenring were typical for the German circuit, with cool, overcast morning sessions giving way to warm and sunny conditions in the afternoon. This large difference in track temperatures between sessions made finding a setup more of a challenge than usual and tested the riders, teams and tyres to the limit. Conditions for the race were fine and sunny with a peak track temperature of 39°C.
Q&A with Shinji Aoki – Manager, Bridgestone Motorsport Tyre Development Department
Sachsenring has a reputation of being a very tough track for tyres. Can you summarise the reasoning behind Bridgestone’s tyre allocation for this race and how the tyres performed?
“Yes this circuit is challenging for tyres - especially for the rear - and so our tyre allocation for the German Grand Prix is quite different to what we usually supply. This circuit features many large-radius, left-handed corners and so the riders are at large lean angles for long periods of time which is what generates very high temperatures in the left shoulder of the rear tyre. As a result, the difference in the hardness of rubber used on the left and right shoulders of the asymmetric rear slicks is the largest for any circuit. There is also a larger gap than usual in the hardness of our two front slick options at Sachsenring, with the soft compound being offered alongside the hard compound front slick. These two front slick options provided the riders with a very wide operating range to manage the cool morning and warm afternoon sessions and we could see that in the morning sessions, the softer front option was more popular as it gave better warm-up performance while in the afternoon, the hard option was used so these front slicks worked exactly as intended.
“The weekend started out being quite tough for some riders as the cool right side of the tyre caused by the infrequent right-hand corners resulted in a few incidents. However, we were always confident that our tyre allocation was up to the task and we saw that as the race weekend progressed, the pace improved and fewer incidents were recorded and Sunday passed almost without any incidents. This was the result of the teams, riders and Bridgestone engineers working closely together to find a bike setup and tyre combination that allowed the riders to find a good rhythm around this technical circuit.”
With such a high demand placed on the rear tyres at this circuit were any problems encountered with the rear tyres this weekend?
“Sachsenring is one of the circuits where we have supplied heat-resistant rear slicks for quite some time, but this year was the first time we provided this option in the soft compound option solely for the CRT riders. We kept a close watch on the wear characteristics of these soft rear slicks in case excessively high tyre temperatures were recorded and in general, this option worked very well and stood up to the demands of this circuit. It was pleasing to see three CRT riders in QP2 and again the performance of Aleix Espargaro using this soft CRT-specific tyre option was very impressive. Overall I was pleased with how all our tyres performed at Sacshenring as it really is a severe track for tyres and the pace during the race was very fast with no signs of excessive wear after the race.”
As Sachsenring only has three right-handed corners would asymmetric front slicks solve the problem of having the rubber on the right side cooling excessively?
“We may investigate developing an asymmetric front slick, but good front-end feel from the motorcycle is very important to a rider feeling safe and confident, so many factors need to be considered. Having rubber of different hardness on the left and right shoulders of the front tyre can affect the feel and balance of the bike, especially under braking and changes of direction. In this case, such handling problems would outweigh any benefit so an asymmetric front tyre might not be the best solution. In any case, an asymmetric front tyre wouldn’t solve the problems encountered at Sachsenring as the right shoulder of the tyre would still lose temperature as the distance between right-handed turns at Sachsenring is so vast. The layout of this circuit means that riders will always have to take extra care when negotiating right-hand corners and on Sunday they proved that there are ways to ride this circuit at a competitive pace without incident.”