2011 MotoGP Assen Friday Round Up: Tire Talk, And 11.1 = 11.0

It's funny how the mood of the paddock can swing. There was much to talk about after qualifying on Friday - because race day is on Saturday here, a hangover of Assen's Dutch Reformed Church past - such as Marco Simoncelli's second pole, Casey Stoner's relatively lowly 3rd place, Jorge Lorenzo missing out on the front row twice in 7 races, Karel Abraham - yes, the kid with the rich daddy, or perhaps we should say the really, really fast kid with the rich daddy - being quickest of the Ducatis, and Valentino Rossi struggling with the GP11.1 just as much as he did with the GP11.0. But instead, all anyone wanted to talk about was tires.

The topic got chewed over by every rider, journalists moving from hospitality unit to hospitality unit to ask the same questions, and receive the same answers, more or less, the only variation being in the solutions offered. The problem, of course, is that the Bridgestones are simply too good. MotoGP's spec tires offer phenomenal levels of grip - in an offhand comment, Casey Stoner referred to 58 degrees of lean as "not that much" - with outstanding duration. It is common for riders to set their fastest laps in the second half of the race, the point at which the tires are supposed to be degrading and losing grip.

The downside to all that grip is that it is only available once the tires are up to temperature, and achieving that is sometimes very difficult. The only way to get the tires up to temperature is to push them hard, getting hard on the brakes into a corner, before slamming the bike onto one ear to load the tires. However, if the tires aren't warm enough, they just let go, the rear being especially treacherous in this respect, sliding, then gripping, then launching the rider into low earth orbit, or just letting go and lowsiding the rider through the gravel.

The morning FP2 session had examples of almost every type of cold tire crash, though curiously, only the Repsol Honda bikes were involved. Casey Stoner - assisted by a small patch of water - flicked off his RC212V in the first minutes of the session, a minute later, Andrea Dovizioso had a huge cold-tire highside in exactly the same spot (Nicky Hayden later diagnosed the crash as a closed-throttle incident, where the rear just comes round with nothing you can do), then finally, another minute later, Hiroshi Aoyama - subbing for the still injured Dani Pedrosa - lost the bike in the frighteningly fast Ramshoek.

The common factor in all these crashes was Assen's lack of left-hand corners, Stoner and Dovizioso going down at De Bult, the third left hander on the track, Aoyama at the Ramshoek, the fourth. There is the best part of a mile between the third left hander and the fourth, and only one more time the bike gets onto the left-hand side of the tire before crossing the finish line, that being at the final chicane. The left-hand side of the tire has plenty of time to cool off, which it rapidly does.

Even the infinitely experienced Loris Capirossi got caught out by the tires, falling very heavily during qualifying and dislocating his shoulder and injuring his ribs. Capirossi's injury means that we once again have a man short on the grid, and this is precisely the problem: the Bridgestones, brilliant as they are, can be a little precocious, and when they let go, people get hurt.

This is precisely the objection that was raised in the Safety Commission on Friday. A larger attendance than normal (though far from massive) saw subjects as diverse as different types of astroturf and resurfacing at Silverstone covered, but a big part of the discussion was about the need for a different approach to the tires. Cal Crutchlow led part of the debate, comparing his experiences with the World Superbike Pirellis, which warm up almost immediately, but lose grip towards the end of the race. Designing a tire like that is not something that Bridgestone is able (or willing) to do in the short term - though they are working on the problem - and so that leaves the riders scratching around for solutions.

More tires is one solution, though a bigger step between the hard tire and the soft is a much more popular one. Yet another is to have the ability to change the allocation numbers so that riders can take more than just a single extra hard or soft front tire, but can instead decide to take a lot more soft rears when it's cold or hard rears when it's hot. Currently they get 5 soft rears and 5 hard rears, and they are sometimes left with a large pile of either unused or unusable tires. Allowing riders to have 7 of one compound and 3 of the other might solve this problem altogether, but that would require Bridgestone to produce a lot more tires.

The real solution is to make tires that warm up faster and degrade a little bit more, which is exactly what Bridgestone have already done. Unfortunately, they did it based on the data from last year, and 2010 was rather exceptional. For the first half of the year, every race we went to was hot and dry, allowing the tires to get up to temperature quickly. This year, we're having an exceptionally cold and wet year, and so the gains the new tires have made in warmup time have been lost in track temperature. The track temperature for qualifying at Assen in 2010, for example, was 15 degrees warmer than the same session this year.

Bridgestone offered to solve the problem this weekend, by first offering to cut the tires to allow them to warm a little more quickly, and then offering to ship a whole selection of tires with a one-step softer compound on the left-hand side, to cope with Assen's lack of left handers. But the trouble is, Bridgestone must offer the change to all the teams, and the rules state that the tire allocation can only be changed if all the teams agree. There was no unanimity for the cut slicks, and then there was no unanimity on the softer rear, and so the truckload of Bridgestone tires on the road from the factory's storage facility in Germany was left in limbo, making the journey in vain.

The hunt is on for the team that rejected the offer of extra tires, but so far there has been nothing but conjecture. Repsol Honda are prime candidates - Casey Stoner is a known fan of the hard tire - but then it was the three Repsols that went down on cold tires this morning. Marco Simoncelli and Ben Spies have done brilliantly in the cold conditions, though Spies' teammate Lorenzo has lacked confidence just as he has lacked grip. This time tomorrow, once the media have spoken to all the riders, the truth will out.

The cold is what is playing merry hell with Valentino Rossi's GP11.1. The MotoGP legend has clearly not forgotten how to ride - bagging the 2nd fastest time on a brand new bike in the wet was proof of that - but in the cold conditions, the destroked GP12 is proving just as treacherous as the GP11.0, the bike Preziosi designed for this year. The old problems are back - a lack of front end feel - something that Rossi and his crew had hoped would disappear along with the old design.

Their hope was based on the way the GP12 had responded during testing, Rossi praising the front end feel of the 2012 Ducati Desmosedici after testing the bike at Jerez and Mugello. The problem, it now appears, is that the weather at Mugello has been perfect - read: dry and hot - while conditions at Assen have been anything but. The rear of the new bike is still clearly improved, but without any feeling in the front, there is nothing Rossi can do.

His team tried turning the bike upside down, but as both Casey Stoner and Nicky Hayden said so many times last year, the sweet spot on the Ducati is so small that if you don't get within a gnat's whisker of it first time round, you have no idea it's even there. Burgess and the team have some more ideas for Saturday warmup, but the outlook is not good until they get to Mugello, a track that has both plenty of data and nice, hot, Italian sunshine. Those could be the two magic ingredients that soothe Valentino Rossi's pain. Until then, he can only hang on, and keep trying to figure out the mystery of the Ducati.

Total votes: 206
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Comments

I seem to remember Simoncelli was already on pole in Catalunya. Or was that in my own private parallel universe?

Total votes: 215

I have no idea of what to expect from tomorrow's race.
Just a thought.

Total votes: 230

I checked where Simoncelli had had his other pole - Catalunya, as you say - my brain thought second, but my hands typed first. I was already half a sentence further in my mind. Sorry!

Total votes: 218

Thanks for the read David. Appreciated as always.

I wonder if perfect conditions in Mugello will be enough for the GP11.1 to turn on the pace? It was great to see Hayden's effort rewarded somewhat, qualifying ahead of Rossi would have been a small consellation prize for not getting the update as early as he would like, and a point being made of it at the pre-event presser.

Karel and Cal - great to see these guys up at the pointy end too!

Bring on.. ...Saturday!

Total votes: 233

Hayden would have the GP11.1 if he hadn't lost an engine earlier. Because of the engine restrictions he has to wait until Laguna Seca I believe.

Total votes: 220

From what I understand, a hard/stiff carcass construction heats slowly b/c the relative lack of carcass flex reduces friction (inside the tire) and reduces operating temperature and the rate at which the tire comes up to temperature. A softer carcass flexes more which increases friction and heat. AFAIK, MotoGP bikes have reached the point where hard carcasses are required to support the bike as it corners, particularly during corner entry with heavy trail braking.

I know my description is a highly simplified model for MotoGP tire performance, but imo, if Bstone make the tires softer, the bikes will be slower. If the tires hold less speed through the corners, the fuel computer will interfere even more than it does already. The riders will push even harder into the corners to save fuel. They will crash just as often, imo. Even if the crashes are more predictable, I'm not sure that will make the sport any safer.

Get rid of 21L. Going in will not be as important as getting out. The 81mm 1000cc 4-cylinder engines will be more controllable than any two stroke or 990cc engine regardless of how much or how little traction control a team runs.

Total votes: 226

Essentially your correct (regarding the cause of differential tire heating). From an academic standpoint, however, the softer tires heat up due to the increase in mechanical work being applied to them, not friction.

Total votes: 223

So some of the flexing work that would otherwise be done by the chassis or the rider is done by the tires? Is that the gist of it?

Total votes: 211

Assen has four left-hand corners, but effectively it is only three. The silly new Strubben corner is a hairpin and so incredibly slow that you don't put any heat in the left side of the tyre, especially because it tightens at the end. Therefore the bikes are just being picked up and accelerated from a sort of standstill, not a nice widening exit that heats up the side of the tyre. This makes the Ruskenhoek (halfway the track!) effectively the first left-hand corner, and it's a fast one. We've seen a lot of nasty first-lap crashes there over the years since they messed up the Northern loop. Now it has caught out Capirossi, among others.
As a rule, it is a bad idea to put left-hand hairpins in a track that goes clockwise. You use up 180 degrees of precious left-hand corners (which you have 360 degrees less of) without working the tyre. Instead, a clockwise track should have right-hand U-turns.

Total votes: 221

Stiff carcasses jam the tread, and cause the tread to slide and heat up while keeping the carcass cooler. A soft carcass, allows the tread to grip the road more, reducing slip and keeping the tread cool while flexing and heating the carcass.

Total votes: 234

will be interesting to see if simoncelli's enthusiastic approach to close quarters racing works on spies, im expecting a pretty good race between these two.
is the forecast for saturday warmer? if it is i suspect lorenzo and stoner will look a lot better during the race.

Total votes: 226

I have complained for a while that bridgestone should make their tires a bit easier to get heat into. But it was because of teams like Suzuki or riders like Elias having such issue with the tires that I said it. I really do hope to see bridgestone make their tires more chassis friendly so we can see more people up front and let riders ride more like how they choose vs how they need to.

Total votes: 230

The spirit of the rule seems to be taking a shoeing by HRC in this particular case, if indeed they are the team rejecting what appears to be a sensible proposal to try and eliminate the problems caused by cold temperatures.

What's worse..Ducati using parts that have been tested in the 2012 bike tests this year, or Honda denying their own and others a wider safety margin by rejecting the Bridgestone offer because they think they will lose an advantage?

While I wouldn't dream of wishing injury on any rider, maybe it would have served Honda right if the riders who crashed in QP were unable to line-up for the race.

Total votes: 232

The Yamahas were running pretty well today, too. There's no proof it was Honda denying the soft tires.

Total votes: 211

If you wouldn't dream of wishing it on any rider, why would you say it in the first place and then continue on with a it would serve them right? I think there was only 2 crashes in QP and one of them was Capirossi who unfortunately will not be lining up on the grid. I guess you meant the FP2 crashes and in particular the HRC team.

Total votes: 225

that we had a huge thread the other day where 90% of posters were up in arms, claiming Rossi and Ducati were cheating, despite the fact that the editor spelled it all out for you that there was no infringement, yet Hondas veto on Bridgestones attempt to alleviate a potentially dangerous situation where riders are getting hurt doesn't even warrant a comment by so called 'fans'?...

For a highly regarded site in which you, the poster, are supposed to take much of the credit for that reputation, it is borderline laughable.

In the interest of balance I feel compelled to keep prodding you lot in the ribs.

Total votes: 215

We do not know who has vetoed the decision, nor how many, nor why. Safety is paramount for all riders, they may have some very legitimate reason for not wanting to change. Not every paddock development needs to be a conspiracy. Race day is a little late in the piece to be bringing in rubber of an unknown quantity do you not think?

Nonetheless the difficulties with the 'stones harks back to the early nineties when the Michelins would grip, grip, grip then bang - low orbit, no warning.

Total votes: 227

tweeted this morning that Lorenzo is unhappy with Honda as he feels it is directed at him..

We have 'giants' in the paddock alluding to this, yet you choose to pass it over because it doesn't suit your agenda?..see what I mean about laughable?

Total votes: 213

Steve Parish says it was Marco Simocelli who vetoed the softer option tyres.

Total votes: 196

I think he may regret that decision now...

Total votes: 219

Simoncelli was directed at Lorenzo, as we've all seen in the first lap

Total votes: 229

Well Steve Parish said it was definitely Simoncelli, but speculated that HRC probably gave their OK in the form of: it was his choice and he decided to take it.

Total votes: 233

Bridgestone have made tyres for global warming instead of climate change.

Total votes: 234

It's interesting that two of the heaviest riders, Sic being the heaviest in the field at 76kg and Spies being the third heaviest at 71kg, and both of them being the heaviest by far on their bike, are at the front by a large margin. Meanwhile, the top Ducati rider is also the heaviest on that bike. Abraham is 72kg, five kg heavier than Rossi and three heavier than Hayden. Dovi is the lightest true Repsol rider right now at 54kg, four kg lighter than Stoner and obviously 22 kg lighter than The Sicness, you can't count Hiro.

Why don't the light riders ballast the bikes in order to get more heat into the tires? Of course the balance and placement would matter, but it might do them a lot of good.

Elias has nothing to lose by trying it.

I think the reason it might matter here is because the balance of the track, with such a long distance between the lefts and having twice as many rights as lefts, and Bstone not bringing an asymmetric tire. All the other tracks this year that have an sizable imbalance of left to rights have been supplied with asymmetric tires, but not here. Why?

Total votes: 218

I'm pretty sure they brought asymmetric tires. The replacement tires are just even softer on the left hand side.

Total votes: 208

Correct, the tires are asymmetric, the replacement tires would have had an even softer compound on the left hand side.

Total votes: 244

My understanding is, the hard tires are asymmetric, the right side being harder and the left side being the same compound as is on the soft tires. So the hard tires are asymmetric, but the soft tires aren't. I thought that's what Stoner said in the post QP press conference. Am I mistaken?

Total votes: 199

Why not just take a pound or two of air out of the tires rather than add weight?

A lot simpler, just as effective and wouldn't penalize acceleration for the tiny tots.

Total votes: 227

I agree. Despite the point made by Simoncelli at the start of the season that smaller riders have a fuel consumption advantage, it definately seems the bigger riders have an advantage with the Bridgestones in cold conditions. I guess the difference is a lighter weight rider could always ballast the bike if they wanted to, where Simoncelli and Spies would have to lop off a limb to get much lighter. Still it backs up the argument that there are pro's and cons to rider weight at both ends of the spectrum and no minimum weight rule should be introduced.

I would bet my bottom dollar it was Gresini who have vetoed the softer tyres from Bridgestone. Simoncelli (and Spies) were able to throw the bike at the corners with abandon where the other riders had to be tentative to avoid a cold tyre crash. Gresini would not wnat to give up give up the advatage they have with the current Bridgestones.

Total votes: 217

Except that HRC could probably quickly 'persuade' Gresini to tow their line. I'd be amazed if it was a non factory team at the bottom of this.

Total votes: 242

I saw the previous thread on the GP12 vs GP11.1 vs GP11 ..
perhaps it was buried in there somewhere .. and my 2 brain cells
can't find it ..

Does the GP11.1 crank rotate "forward" or has Ducati done a Yamaha
and reversed the engine rotation to reduce the total angular
momentum of the bike (wheels + engine) to make it easier to turn?

One of the long standing complaints was "it doesn't turn" .. getting
the bike leaned over. My perception is that a forward rotating crank
may provide more net horsepower (as it doesn't have hp losses through
a jackshaft that an 'oppp' rotating crank would require to deliver forward
drive rotation to the chain), but its angular momentum is additive to the wheel rotation.
The gyroscopic effect can be quite strong.

I understand Rossi & Burgess wanted a heavier crank to dampen down
the engine response when applying the throttle whilst exiting the corner.

I read the comment on the crank and conrods being different
from GP12 to GP11.1 to get to 800 cc, didn't see anything re rotational
direction.

David - would you please peek under the fairing of the GP11.1 and see if
there is a big Rotational Arrow cast or engraved on the Ducati engine case
indicating crank rotation direction? :-) Inquiring minds wanna know!

notfamousyet

Total votes: 208

Another informative article from Mr Emmett. With the combination of the Assen layout and the temperature it looks like this will be another red herring of a race. I hope that no more riders are injured and the planet heats up in time for the next race.

Total votes: 208

@ Mr notfamousyet

The old Ducati V twins rotated backwards and the final drive was via a sleeve gear fitted on the end of the mainshaft, it being driven by the layshaft through the selected gear of course. Thus there is no need for a jackshaft. I know that this may be clear as mud but I am sure you might be able to find an exploded diagram somewhere to see what I am saying. I have to find the teardown pictures of the desmosedici and have a look at those now.

Total votes: 218

I have a bunch of 916, 749, 848, and 1098 engine parts and there is no sleeve gear as you describe. I also have a bunch of pics from a Desmosedici teardown and the crank to trans to sprocket gear arrangement seems completely conventional.

Chris
http://moto2-usa.blogspot.com/

Total votes: 224

He means OLD, not a 916... jeeessh that's a modern bike Chris. :-) He's talking bevel drive Ducs, proper old ones. Laverda used the same sleeve gear arrangement, in and output both on the mainshaft, via the layshaft. Not so sure it would be a wise choice for a 200+hp bike though.

Total votes: 195

About time Karel Abraham should start getting some credit for his performances. Despite having the rich dad/playboy racer tag he has delivered solid results and seems to be improving each GP. BBC reported he had to sign a contract with his dad's team !

Total votes: 224

Yes he definitely deserves credit. He is having a great rookie season thus far.

I remember when Hector & Karel were creeping up the order, and often sitting in front of the factory machines - it was waved off by other riders as getting a tow. Karel of note cannot simply be overlooked anymore imho. He is doing a great job and is definitely at the right end of the pack. Hopefully he stays there.

As for tows, I was curious to how Gresini would react to Simoncelli and Rossi seemingly slingshotting their way around the course together. It's not the first time and I was probably reading into it more than I should have, but you would think that it's in Gresini and Honda's best interest to see the Ducati of Vale as far back as possible.

But yeah, as I said - I'm likely reading into things too much given the current political minefield that is the MotoGP circus at present.

Total votes: 215

I know Bridgestone only bring two compounds to each G.P. My understanding is this was based on their experience of the track, abrasion levels, mean track temperatures, and weather forecasts. But not all G.P"s are going to fit inside this neat little box are they? Especially not the notoriously fickle circuit of Assen.

I remain very puzzled as to why Bridgestone are not better prepared for these eventualities by having more options available (to choose the two weekend compounds) to use the night before - or even on the morning of practice. Especially in Europe.

Total votes: 207

Bridgestone never wanted to become the only supplier for motogp, it took some effort from dorna to convince them. Bridgestone put some conditions and now everyone is getting what they said they would have brought.

Total votes: 231

Why not put an over under bridge in at the pinched part and turn Assen into a figure 8?

Total votes: 235

Perhaps make it a jump like SuperCross to spice it up a bit? Ha!

Seriously, not a bad idea at all.

Total votes: 214