Last weekend’s Dutch TT at Assen was affected by variable weather conditions that resulted in the race being a flag-to-flag affair at which Repsol Honda’s Marc Marquez won ahead of Ducati’s Andrea Dovizioso and Dani Pedrosa on the other Repsol Honda RC213V.
Fine conditions on the opening day of practice gave way to increasingly poor weather that culminated in a downpour of rain during the lead up to Saturday’s race. All except two of the twenty-three starters at the Dutch TT, Broc Parkes and Yonny Hernandez who started on slicks, started on soft compound wet tires, but by the time a third of the twenty-six lap race had been run, all entrants had changed to their second bikes fitted with slick tires.
Q&A with Shinji Aoki – Manager, Bridgestone Motorcycle tire Development Department
“The kind of mixed conditions that we experienced for the race are really challenging for the riders. Grip levels can change from corner to corner, so the riders need tires that get up to temperature quickly and have very high grip levels. The fact that we had almost no incidents during the race and the riders managed to show quick pace on a drying track that still had some patches of water was very positive for us. The wide working temperature range of our slick and wet tires was one of the key factors that allowed the riders to push in the tricky conditions with confidence.”
During Free Practice 3 when the track was only slightly wet, some riders left their box on wet tires only to return to the pits after not even completing a single lap. Can you explain what is happening here?
“Some riders like to ‘scrub’ a set of wet tires by doing a lap on them in case they need to be used later in a race situation. The purpose of scrubbing is not to remove some kind of coating on the tire as some people believe; rather it is purely a mental exercise for some riders as perhaps they feel more confident pushing on a set of wet tires that aren’t brand new. Even when there is no possibility of rain on race day, some riders will still scrub a set of wet tires during the morning Warm Up session in case there is unexpected rain before the race. Technically speaking, a scrubbed wet tire has no advantage in terms of grip compared to a new tire as our wet tires offer maximum grip at the very beginning of their life.”
No Factory Honda or Yamaha riders tried the hard rear slick over the race weekend at Assen. Was this due to the weather conditions or some other factor?
“The weather conditions on the Thursday at Assen were well suited for the hard specification rear slick, but as it was the first day of practice, the Factory Honda and Yamaha riders preferred to use the medium rear slick to assess grip levels and find a base bike setup. This is quite a normal procedure. Some of the riders planned to evaluate the hard rear slick during practice on Friday, but the weather was much cooler and we had intermittent rain and in these conditions, the medium compound rear slick was the better choice. In any case, the difference between the medium and hard specification rear slicks provided for Assen are quite close, so if track temperatures for the race were towards the forty degree range, some riders would have selected this option.”