Honda and Yamaha ready chassis updates for Sepang

Honda and Yamaha are both likely to roll out new frames at this week’s second Sepang test to try and solve a chronic chatter issue with their new 1000cc projects.

The new safer rear Bridgestone tyres that the riders demanded have been designed with a softer construction to generate heat quicker to avoid a spate of sickening cold tyre high-sides.

The safety aspect has improved immeasurably, but the new tyres have thrown all the factories a major curveball with the onset of a persistent chatter issue.

Honda boss Shuhei Nakamoto said Casey Stoner and Dani Pedrosa’s complaints about the chatter issue, which is a severe tyre vibration under braking and cornering, meant fixing the problem was number one priority ahead of the first race in Qatar on April 8.

Stoner and Pedrosa each tested a new frame at the first Sepang test earlier this month based on their feedback from the pre-Christmas test in Valencia, but the update hasn’t eradicated the chatter.

Nakamoto told MCN: “The chatter problem is generated in several ways and usually you must change the stiffness of the chassis, the wheel or the forks or all of them.  It is not easy to fix the problem because we don’t why the bike is chattering like this.

“Casey doesn’t like the new specification tyres because of the chattering. Our number one priority is to fix the chatter and we don’t have a solution yet. Chatter can be very difficult to solve, it can be mysterious problem sometimes.”

Jorge Lorenzo’s factory Yamaha boss Wilco Zeelenberg said: “The new tyre is safer with more grip.  But the chatter problem is something all teams are working on, we need to fix that, but it could take time because the dynamics of these bikes are different.

“It is a combination of the tyres and the new engines. You try to fix it with different chassis stiffness and other solutions but that is very difficult. To constantly change the chassis for chatter means you can lose some steering feel or other positive points.”

The three-day Sepang test kicks off tomorrow (Tuesday) and there will be full and exclusive coverage in the March 7 issue of MCN.