MotoGP: Bridgestone Tire Talk, Brno
Motorcycle Grand Prix racing recommences in the Czech Republic after the summer break as MotoGP heads to the Automotodrom Brno circuit, located 200km south west of Prague.
Brno is characterized by its dramatic changes of elevation which total more than 73metres from the circuit’s highest point to its lowest, and this rollercoaster of tarmac creates specific challenges for tires.
Weight transfer of the bikes is affected by the elevation, which consequently generates increased pressure on the tires. Downhill sections throw weight forward, especially under braking, and so a strong front tire is required for good stability. This is why Brno is one of only a handful of races all season for which Bridgestone have selected extra hard compound front slicks.
The importance of good corner exit speed is greater at Brno as it enables the machines to achieve improved drive and speed along the steep uphill sections of the circuit. This means good rear traction is very important to allow riders to open the throttle as early as possible. Here the uphill elevation changes actually help the rear tyres find even more
grip by transferring weight to the rear of the bike, helping to force the rear tyre onto the tarmac.
Brno’s layout is flowing and reasonably fast, with an average speed of just over 166km/h, as set by Jorge Lorenzo last year on his way to a new lap record. Equal loads are placed on the right and left shoulders of the rear tires so asymmetric slicks are not required. The abrasiveness of the tarmac is quite high, which provides a test of durability and is also another reason why harder front tires are required.
Lorenzo carries a 72-point lead into the tenth round of the season, ahead of Dani Pedrosa and Andrea Dovizioso. Valentino Rossi is in fifth, 13 points adrift of fourth-placed Casey Stoner and looking to regain lost ground after missing four races through injury.
Hiroshi Yamada (Manager, Bridgestone Motorsport Department) says: “The Czech GP is the start of the second half of the season and a crucial time in the title race. Riders must come out strong to carry good momentum through the remaining nine races which are covered in just 13 weeks. Jorge has a strong lead but it is all to fight for just behind him. There are fewer than 40 points separating Andrea in third from Ben in seventh with 225 points still available, so I’m looking forward to an exciting second half of the year and a good race in Brno as riders battle to re-exert their dominance.”
Tohru Ubukata (Manager, Bridgestone Motorcycle Tire Development Department) says: “Brno features a number of elevation changes which are particularly tough on the front tires. The downhill corners mean that the weight transfer of the bikes is naturally forward, increasing the load and therefore the temperature of the front tires requiring a strong compound. The circuit’s surface is also very abrasive, since its resurfacing in 2008, which makes tire durability more of a challenge. The combination of these factors means that Brno is one of only four races in the season to which we will bring the extra hard compound front slicks.”
“The corners are generally fast and flowing so the lateral loads generated are high and require good shoulder stability from the rear tires and good traction on corner exit. Excess sliding can rapidly accelerate tire wear given the abrasive tarmac so machine setup and riding style play an influential role in tire durability.”
Bridgestone slick compounds available:
Front: Hard, Extra Hard.
Rear: Medium, Hard