Bridgestone MotoGP Preview - Round 8: Dutch TT, Assen
Round eight of the 2015 MotoGP season is the Dutch TT at Assen, an event that formed part of the inaugural FIM Road Racing World Championship Grand Prix season back in 1949.
Over the years the layout of the Assen circuit has changed significantly, with the current 4.54 kilometre long circuit featuring a variety of slow and fast corners on a track surface that offers only modest grip. Although it features many fast sections, Assen is one of the least severe circuits for front tyres. Also, as temperatures at Assen are generally cooler than at other rounds, the front slick tyre allocation for the Dutch TT is comprised of Bridgestone’s softest rubber compounds.
However, the fast right-hand turns - in particular the sequence of corners from Mandeveen to Hoge Heide - generate significant temperatures on the right shoulder of the rear tyre. As a result, asymmetric rear slicks with rubber that is one step harder on the right shoulder than the left are provided at Assen. Overall, the rear tyre allocation for the Dutch TT needs to provide good edge grip to help riders maintain high corner speeds, with good heat resistance to cope with the fast, high camber corners.
Front tyre options for Assen are the extra-soft, soft & medium compounds. Rear tyre options for the Factory Honda and Yamaha riders are the medium and hard compound rear slicks, while the factory Aprilia, Ducati, Suzuki and Open-class riders get access to the soft and medium compound rears. Due to the Assen circuit being moderate in terms of tyre severity and the low grip level of the tarmac in wet conditions, the main wet tyre this weekend is the soft compound, while the hard compound is the alternative option.
Hiroshi Yamada - Manager, Bridgestone Motorsport Department
“As we draw close to the halfway point of the season, we make our annual visit to the amazing Assen circuit for the Dutch TT. This is a race where for the past five years we’ve had five different winners and an important factor at Assen is the weather, with unsettled conditions in previous years creating some challenging, and often exciting racing. The layout of Assen is a mixture of slow and fast sections and is generally quite technical and looking at the results of recent years, Honda and Yamaha have both enjoyed success here, and Ducati also had a rider on the podium here last year. With this in mind, I hope to see many manufacturers battling for the podium this weekend and that the Dutch TT’s tradition for producing spectacular races continues.”
Shinji Aoki - Manager, Bridgestone Motorcycle Tyre Development Department
“The Dutch TT is an event which can experience a wide range of ambient and track temperatures, so our tyre allocation at Assen has to be effective over a wide range of conditions. Assen is a fast and technical circuit that requires asymmetric tyres because of the high loads placed on the right shoulder of the rear tyres. The tyres at this circuit have to cope with a wide range of corners from very slow, to high speed sections like Ramshoek, so the layout requires tyres that give high levels of edge grip. The first few corners all flow into each other while gradually tightening, and this requires good stability and heat resistance from the right shoulder of the tyre.”