Chatter Costing Casey Stoner Vital Time
Despite serious chatter issues, Casey Stoner left Jerez a winner, taking first in a tight race with Yamaha rider Jorge Lorenzo.
The severe chatter issue that has plagued Casey Stoner on Honda’s new factory RC213V machine is costing the reigning world champion precious tenths-of-a-second a lap.
Stoner’s Repsol Honda
crew chief Cristian Gabbarini says the chatter, which is a vibration on braking and corner entry, means the Australian is being prevented from being able to push at 100%.
Stoner has been handicapped by the chatter issue ever since new softer construction tires were introduced by Bridgestone after riders requested better initial warm-up performance to avoid a spate of nasty high-sides on cold tires.
HRC technical staff haven’t been able to find a solution to the chatter problem and a new or modified chassis is expected to be made available for Stoner and Repsol teammate Dani Pedrosa
to assess during a forthcoming one-day test session immediately after the Estoril race in Portugal.
The chatter issue was a major factor for Stoner during the season’s opening round in Qatar. “It is difficult to judge but I think it costs him some tenths for sure,” said crew chief Cristian Gabbarini. “It is impossible to push at 100% because you don’t have the feedback from the tires, so you must keep some safety margin. The grip conditions are what can make a big difference. In general the new rear tire amplifies the chatter a lot in our bike and we knew this right from the beginning when we first tested the softer tires. In some circuits we have reduced to an acceptable level but in Qatar it was lot. Every time we go out on track we find a different condition so the chatter increases or decreases always. Unluckily for Casey, it is from the beginning of the corner when he brakes to the end of the exit. Through the whole corner he has chatter. So from the moment he brakes to the moment he picks up the throttle, he has chatter. It is just that it moves from the front to the rear. Basically the sensation is that the tires are jumping across the surface and you can see this easily on the data. I’d say ‘tires jumping on the ground’ is the perfect way to describe this problem.
“We have some ideas to improve it but if something is coming from the factory then sure it is welcome because with a problem like this we must work to solve it as quickly as possible. I don’t think it is a problem we can’t solve but we have to think about it and work hard. We need something different for sure, but whether that is new I’m not sure. Maybe we can modify something. Usually when the chatter happens it is a combination of grip levels, stiffness of the tires and stiffness of the chassis. It is too early to say what the issue is.”
The chatter issue is also having an impact on team Pedrosa but Gabbarini feels Stoner’s difficulties may be exaggerated by his riding style.
Gabbarini added: “I know Dani suffers a bit with this problem but less than Casey. A lot can depend on the riding style. Casey is a rider that puts a lot of force into the tires to find good grip, but when you are putting that level of stress on the tires, the chatter increases. He brakes really hard and deep into the corner, so this puts a lot of force on the front, and he likes to pick up the bike quickly to exit and that creates a lot of force on the rear.”
Stoner believes radical solutions like a completely new frame are going to be a last resort measure to fix the problem, but he added that “we have a limiting factor with chatter, so I think if we can get rid of most of it we will be right. The boys do have a heck of a lot work to do to try and fix that because I'm not the only Honda rider with this issue. So if we can fix that then it will be happy days. If they (HRC) find something through their studies then that is great but if they need something new then we might have to do that. But that's a last resort, we are going to try and get everything we can out of what we have got."'
Dani Pedrosa Rues Cautious Start
Dani Pedrosa led the opening laps at Jerez but fell behind as wet patches on the track challenged his confidence.
Dani Pedrosa’s hopes of capturing victory in front of his home fans at the Jerez circuit in Spain were dashed after he rode too cautiously in the crucial opening laps.
The Repsol Honda rider blamed himself for not threatening Repsol Honda team-mate Casey Stoner
and fellow Spaniard Jorge Lorenzo more in an enthralling 27-lap race.
Pedrosa led for the opening two laps before dropping back to fifth as he struggled for confidence with damp patches scattered around the track following earlier rain.
Several crashes on the damp sections had occurred in the earlier Moto2 and Moto3 races and Pedrosa said, “I had a pretty strange race. I started well but then immediately I dropped back. In this situation when you are first you don’t know really well the track conditions and I was too cautious in the beginning. I watched the Moto3 and Moto2 race and saw many crashes in the beginning with these wet patches. So I was too calm in the beginning and then Casey and Jorge made a big gap. I was too long behind Nicky (Hayden
) and (Andrea) Dovizioso. I lost a lot of ground there, so when I got past them I think it was maybe lap nine or ten and I was too far behind. I started to push harder and harder and I lost the front a few times in the fast corners. Then I kept my focus and Cal started to push from behind. I started to improve my lap time a little bit and then I started to catch them back but it wasn’t enough. I couldn’t really get close to them in the end and I knew Cal was using the hard front tire, so he really had some extra advantage on the braking. But I could hang onto make a third place.”
Having been fourth in the opening two races, Pedrosa said it was Crutchlow looking the most likely to emerge as a big threat to the three top riders in 2012.
He added, “Looking at the results, Cal from last year is the one that has made the biggest step. But still Andrea (Dovizioso) is also close and I think Nicky is doing well on the Ducati also. But something has gone strange with Ben (Spies) in the start, but sure he has the pace also.”