German MotoGP debrief with Shinji Aoki
The 2014 German Grand Prix at Sachsenring saw Repsol Honda’s Marc Marquez secure his ninth successive victory and complete a clean sweep of the first half of the MotoGP season. It was a successful weekend for Repsol Honda with Dani Pedrosa taking second place on the rostrum, while Movistar Yamaha MotoGP’s Jorge Lorenzo also handled the tricky conditions well to finish in third place.
A brief rain shower before the start of the German Grand Prix resulted in the race starting on a track that was mainly dry but with wet patches in the final sector. The challenging conditions resulted in nine of the twenty-three riders lining up on the grid on slick tires, while the remaining fourteen riders started on slick tires from pit lane after changing bikes during the warm-up lap.
Q&A with Shinji Aoki – Manager, Bridgestone Motorcycle tire Development Department
Sachsenring is renowned as a tough venue for the riders as well as the tires. What makes it such a challenging circuit for tires and how does this influence tire development for this track?
“There are many factors that make Sachsenring one of the most difficult MotoGP circuits in regards to tire development. First of all, the tarmac is very abrasive which causes high wear rates, and then there are numerous long sweeping corners where the riders spend extended periods at high lean angles which cause extreme tire temperatures on the left shoulder of the rear tire. Also, there are just three right-hand corners compared to ten left-hand corners and so we need to engineer the left shoulder of the tire to resist extreme temperatures, while the right side suffers the opposite problem, it has to be engineered to warm-up quickly and retain temperature. The elevation changes also mean that the front tires have to provide a lot of stability under braking, so all these different elements need to be considered when developing tires for the German Grand Prix.
“Looking at the results from the race weekend, I’m pleased that we were able to supply a tire allocation that struck the right balance between rider safety, performance and durability. The race took part in mixed conditions with wet patches on a drying circuit yet we almost got through the race without a single crash, while a new outright lap record was set by Marc Marquez in qualifying on Saturday.”
The previous race at Assen also started in mixed conditions, although this time all the riders elected to start on slick tires. Considering parts of the circuit were fully wet, was this a surprising decision?
“Although the tarmac at Sachsenring and Assen are different and don’t offer the same level of grip, I believe that the experience the riders had in mixed conditions on slick tires at Assen would’ve convinced them that they could comfortably negotiate the damp parts of the track on slick tires. Most of the circuit was dry enough for the riders to push hard and get the tires up to optimum temperature, which would ensure they had enough grip to get through the wet patches safely. The fact that riders could negotiate the mixed conditions last Sunday safely and at a quick pace is due to the development work we’ve done to improve the warm-up performance and feel of our slick tires.”
In qualifying on Saturday, Marc Marquez set a new Circuit Best Lap record, beating the existing record that was set on qualifying tires. Can you explain the basic difference between a qualifying tire and the regular race tires Bridgestone now supplies to MotoGP?
“The old qualifying record at Sachsenring was set by Casey Stoner in 2008 on Bridgestone qualifying tires when he rode for Ducati. The construction and compounds used in a qualifying tire are designed so that the rider has extremely high grip levels for a short period of time, at the expense of durability, so the performance level of the tires would rapidly degrade. These tires were employed during the era of competition between tire manufacturers to ensure the riders they supported would qualify in the best possible position.
“It is an excellent indicator of just how important tires are to the overall performance of a motorcycle, that we can still have lap records that were set on qualifying tires six years ago; given how much the bikes have developed over the last six years. I am also pleased every time one of these records is broken, especially at a circuit that is as demanding as Sachsenring as to have a tire designed to withstand at least thirty laps at this track break a record set on tires that were designed for one or two laps is a significant achievement for us. Marquez set the new lap record on the same tire combination he used for the race and this shows the versatility of our current crop of MotoGP slick tires.”