If anyone was in any doubt about the pivotal role that the spec Bridgestone tires play in MotoGP, this year will have made their significance abundantly clear. The stiff tires offer unbelievable levels of grip, but only once up to temperature, feeling vague and distant while still cold. That presents riders with a paradox: to go fast, the tires have to be warm, but to get heat into the Bridgestones - the front especially - you have to push it hard to make it work.
Championship leader Casey Stoner has proven to be a master at handling this dilemma, seemingly achieving astonishing levels of lean angle and getting his Repsol Honda RC212V turned faster than anyone else on the grid. When asked about the method he uses for getting heat into the tires, Stoner has spoken several times about using the throttle to load the front.
To an untrained observer - and even to people who do have the training - this doesn't seem to make sense. After all, use of the throttle makes the front wheel want to lift, doing the polar opposite of loading the front Bridgestone. To understand exactly what Stoner means by "using the throttle to load the front," we turned to the man who knows exactly what the Australian is doing when he rides the bike: Stoner's long-time crew chief Cristian Gabbarini. Gabbarini, who worked with Stoner at Ducati, and joined HRC when the Australian moved to Honda, took time at Brno to answer our questions. Here's what he had to tell us:
Q: Casey talks about using the throttle to load the front to put more temperature in the tire. Whenever other people talk to me, they say "but surely the front gets light and that doesn't work." So can you explain the mechanics of that to me?
It's not exactly like this. In general, you can load the front by weight distribution, changing weight distribution, or using - I don't want to say too much, but more than normal front brake. To keep the front down and keep the load over the front tire. But when Casey says this, using the throttle, because when you - how to say? - you push more, not just by the throttle, by the speed, you enter in the corner 5km faster than usual, you load more suspension at both ends, you have to brake harder, you have to go in harder, so you load more both tires. When you enter the corner, mainly it's the front. So, in general, when you push more, you load more the front in this phase of the corner.
Q: so you're loading it more on corner entry, and then through the corner as well, but as soon as get on the gas, the load comes off the front?
Usually yes. It's difficult to load more the front using the throttle when you exit. In general, when you exit, and especially in Casey's case, he picks up the bike very quickly, trying to have as little lean angle as possible, to have more acceleration. What Casey usually did and does, he loads the front a lot by braking when he is going into the corner.
Q: So trail braking, braking all the way into the corner
Yeah. You can see the suspension travel on the front is very deep, with a lot of lean angle. He believes a lot in the front tire, and to be honest, this is one good way to make the front tire work, because everybody is complaining about warming the front tire up, you have to push, to stress it, to make it work. But you have to believe in it.
Q: To me this seems to be key. The tire doesn't work until it's hot, but the only way to get it to work is to believe in it and brake hard.
At the beginning, while the bike is still in upright position, you brake hard in the first part and you start to warm it up, because the tire starts to move and so for the internal friction, it starts to warm up, and also the compound starts to move so... Because of the friction in general, you can put energy in and warm up the tire. Then you have to still keep the brake on and go into the corner. In general this is the riding style of Casey.
Q: Next year, the construction is going to be a little bit less stiff from what I understand from Bridgestone...
This is what I heard. But to be honest, we tried just a couple of tires, and it's difficult to say.
Q: Do you think this will make any difference to Casey's style, or will it work anyway?
Sure, both. Casey's style and setting. But as usual, if you have the possibility to choose one tire, also if with the same carcass you use the hardest option of the compound, all the stiffness of the tire overall is higher. So the compound makes a part of the difference.