Netherlands Grand Prix, Assen: Bridgestone Preview

Round seven of the MotoGP World Championship takes the paddock to the historic Assen circuit for the Dutch TT, one of the longest-standing races on the calendar and a race with great history in motorcycle racing. The 81st TT Assen weekend takes place on Saturday 25 June, and marks the 62nd time the race had appeared on the Grand Prix calendar having been included every year since 1949.

The circuit has appeared in various guises over the years, including as the historic TT road course, and last year underwent another change in the form of the re-profiling and smoothing of the Ruskenhoek kink. Allowing riders to carry more speed through the fast right-handed kink, the change made the circuit 13 metres shorter and the laptimes two seconds faster.

The result of all these changes though is that Assen’s track surface is inconsistent and the mix of newer and older asphalt offers differing levels of grip and abrasion, where the new sections of tarmac are slippery and the older parts abrasive. This makes it hard for riders to get a consistent feeling throughout a lap, and very tricky in the wet.

Generally, Assen is not so demanding for front tyres so the soft and medium compounds can be used to generate more grip and more positive feeling for the riders on the slippery tarmac. Loads are high on the right shoulders of the rear tyres though because of the circuit’s fast and flowing nature and specifically the long and fast succession of corners from turn ten to thirteen when the right shoulders of the rear tyres have very little respite. The circuit is fast, especially with last year’s slight change, and now average race speeds are faster than Mugello and Silverstone making it the second fastest race on the calendar.

The asymmetric medium and hard compound rear slicks will again be used at Assen, meaning Bridgestone’s tyre allocation is unchanged from this race last year.

Hiroshi Yamada – Manager, Bridgestone Motorsport Department
“The Dutch TT is one of motorcycle racing’s most historic, and although it has greatly changed over the years, it has a special place in the hearts of many, including the fans. The season is really taking shape now, and especially with this run of six races in eight weeks the momentum is really building. Casey arrives in Assen with the championship lead just ahead of Jorge who won there last year, and we also hope that the recoveries of Dani and Cal are going sufficiently well to see them return to action soon.”

Hirohide Hamashima – Assistant to Director, Motorsport Tyre Development Division
“Assen is a smooth circuit that requires asymmetric tyres because of the high loads placed on the right shoulders of the rear tyres. Following its modification in 2006 there are two distinct types of tarmac; the new part is slippery whilst the old is abrasive, making it particularly tricky in the wet. The circuit was also changed slightly for last year’s race when the Ruskenhoek corner was smoothed out to reduce the total lap length by 13 metres. The tyres have to cope with a wide range of corners from very slow to high speed and shoulder grip is crucial. The first few corners are linked as one and gradually tighten, requiring good right shoulder durability, and corners such as the 200km/h Ramshoek demand absolute commitment and generate relatively high tyre temperature.”

Source: Bridgestone Motorsport