Bridgestone Press Release: Masao Azuma Explains Low Grip, Hard Front And Soft Rears At Jerez

Bridgestone issued their usual post-race press release after the Jerez round of MotoGP, explaining their choice of tires for the Spanish race. The race weekend had raised many questions over tire compounds and low grip, such as why the Yamahas could only use the soft rear tire, while the Hondas could also use the hard rear to some extent, and how the hard front had only barely managed to cope with the conditions. Azuma gives a clear explanation of the differences, and of why Bridgestone made the choices they did. The press release appears below:

Spanish MotoGP™ debrief with Masao Azuma
Wednesday 8 May 2013

Bridgestone slick compounds available: Front: Soft & Medium; Rear: Extra-soft, Soft & Medium (Symmetric)

This year’s Spanish Grand Prix at Jerez took place under resplendent sunny skies and saw local hero Dani Pedrosa ride to victory ahead of his Repsol Honda teammate Marc Marquez and Yamaha Factory Racing’s Jorge Lorenzo in third place.

The warm and sunny conditions presented the hottest track conditions at Jerez in years, with a peak track temperature of 53°C during the race providing a stern test for the riders, machines and tyres.

Q&A with Masao Azuma – Chief Engineer, Bridgestone Motorsport Tyre Development Department

Track temperatures were the highest they’ve been in recent years at Jerez, but all riders chose the softer rear slick options available to them. Can you explain the reason for this?

“To see track temperatures in the mid 50°C range at the first race of the European season is unusual, but the harder rear slick options we brought were for such a possibility. With such high temperatures, it was expected that some riders would select harder rear slicks for the race, but the greasy track conditions meant riders chose softer rears to give them the highest level of cornering grip. Some riders did comment that the drive grip, that is the grip when the rider picks up the machine from full lean angle when accelerating out of corners, was better on the harder rear slick, but edge grip, which is important at the flowing Jerez circuit, was better on the softer rear option - even in the very hot temperatures. Race simulations in practice revealed that the rate of wear on the softer rear slicks was sufficient for the race distance, and this is why every rider selected the softer rear tyre on Sunday.

“The fact that the wide operating temperature range and durability of our softer rubber compounds provided consistent performance over a race distance is positive for us. We had a similar situation at Austin two weeks ago. At that time only two riders selected the harder rear for the race, but the difference is that one of these riders ended up winning the race! In this case riders could lap at a similar pace with harder rear tyre, whereas at Jerez they could not. We believe this was due to the character of the tarmac and the very high track temperatures in Spain. We will now analyse the data we have from the race to see if there are any lessons to be learned for our future tyre development and race compound selection.”

Front tyre choice was also uniform across the grid, but in this case the riders selected the harder option, medium compound front slick. This seems at odds with the rear tyre selection.

“Just as the layout of Jerez requires a high amount of edge grip from the rear tyre to maintain good corner speed, it also requires a great deal of stability from the front-end under braking and cornering. Also, when you consider that track temperatures at the beginning of last year’s race were 30°C cooler than this year, we must also consider warm-up performance, so our front slick tyre compounds for Jerez were the soft and medium compounds. The high track temperatures we experienced this weekend meant that warm-up performance wasn’t such an important factor and so rider choice shifted towards the harder front slick option to give them the most front-end stability. Even though the track conditions were challenging, there isn’t a big difference in overall grip level between our two front options at Jerez, so riders chose the option that gave them better stability in braking and especially cornering.

“Some riders did comment that they would’ve liked a harder front tyre at Jerez this year, but considering the exceptionally hot weather compared to previous years, I think the balance of our compound selection was correct.”

We are three races into the season and each race has presented markedly different track and weather conditions. Have you learned anything new about the performance of the 2013 MotoGP machines that could contribute to a change in future tyre design?

“We are constantly collecting and analysing tyre data, telemetry and rider feedback as part of our MotoGP tyre development programme. As we know, the machine weight has increased by three kilograms this year, and so we are investigating what affect this change - plus the fact that teams have now had a year to develop their chassis, electronics and power delivery to work with our latest generation of MotoGP tyres – has had on tyre performance and will apply these lessons to the development for our next generation of tyres. After pre-season testing and three races we now have a substantial amount of data with which to start developing the tyres for the 2014 season, which we will present to riders for evaluation later in the year.”

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Well, yeah that could never be proven wrong since it was based on past years' data. But the question is why not bring one extra compound and have it available? I understand lots of subtractions from the available sets are based on cost cutting. No qualifiers, no intermediates and only two, very similar according to Azuma, compounds. Shouldn't this race serve as a basis for rethinking that last strategy?

They are on a fixed contract, no competition.
Once-a-year updates?
I'm sure that they would argue that they are making good progress on the technology front, but in MGP I would expect continuous evolution, not wait until the pressure builds and do something when forced (i.e. all the rider injuries/bike damage caused by a not-so-good design.)
Things may be better than they were, but if this product was called 'Ducati' rather than Bridgestone, there would be a lot more people calling for change.
For me the post here that said Michelin would not return unless there was open tyre competition, because of the R&D etc. benefits, said it all.
The single tyre approach does seem to work in superbike categories, but for MGP it needs to be 'prototype' tyres on ' prototype' bikes, IMO.

No pressure? Having to make a single tire to suit motos with 20% difference in power? Developed completely new tires last year, new test tires this year and in between test and race at Jerez making a new special wet tire?

These are prototype tires what about Marquez at Jerez test saying braking the Brigdestone in wet is like Moto2 tire on the dry track?

Michelin are sole supplier to CEV Moto2, Formula E and would probably like to be back in F1, so I think that statement about only wanting competition isn't worth the e-paper its written on. They'd probably like to be back in MotoGP also but dont think they'd like fighting with Bridgestone again.

They have provided a tyre to meet different types/power output, with better warm-up, etc. (Plus a CRT tyre). I don't think that last year's tyre was 'completely new', but you may be right.
The key thing here, for me, is that it has largely become a 'production' exercise (admittedly for the whole MGP paddock) not an R&D-focused exercise. It's about volumes rather than ultimate performance.
My main reason for wishing to see competition is not because I think they are useless at making tyres (or developing them). It's the whole one-choice of tyre (not compound) problem that has resulted in bikes being designed to suit the only available tyre, not being free to get a manufacturer to design a tyre to suit their bike. The supposed cost-saving-measure has resulted in untold millions being spent on trying to get bikes to be competitive. The prime example, Ducati, aren't even allowed to get a tyre made/test it by someone else because of the restrictive rules around these 'components'.
To me, those types of restriction are against the prototype principles that MGP should represent. Plus, the alleged cost saving seems as improbable as cost-saving 800's, and the sporting effect similar, or worse.

And I guess its up to Dorna to see if they can introduce tire competition without the teams having much extra cost and still make it attractive for other tire makers to join.

If it costs Dorna even a single extra euro though I dont think we will see any change.

The difference between making bikes suit the tires or making tires suit the bikes is who's spending the money.
Bridgestone has produced a fine spec tire this year. Just imagine, the Jerez race was 30° colder last year than this year and Bridgestone brought tires that worked in the sweltering heat. No doubt, they know their beans and if a team can't get their bike to work in that very wide operating temp. window it's the bike not the tires that is at fault.
The only thing about a spec tire series is that it must be transparently fair. New tires tested, approved and presented to all the teams before new bikes are designed and then the spec is frozen until the next seasons development process begins. Bridgestone's only fault is supporting Dorna's political manipulation of the championship. I will always support open competition but in the context of the current situation in MotoGP Bridgestone is doing a good job providing safe and superlative race tires.

Leave things as they are. Say NO to the past where certain 'special' riders got special tires at the expense of the other riders getting a lesser tire.

The bike manufacturers need to learn how to develop a bike to fit the tires that EVERYBODY else uses. If they can't ...........then keep on losing and quit complaining. Honda dealt with a substandard tire last year(and eveybody KNOWS why that tire was presented) and overcame it thru developing the bike, not getting a 'special' tire to fit their bike.

it seemed like a good idea to me at the time.
The money comes from the sponsors and fans, but the important thing is what is the cost? If you just look at the tyre contract, a single supplier like BS probably look cheaper than 'open' competition. They may even pay Dorna for the privilege.
However the total cost also needs to include the money spent by the teams to enable them to make these tyres usable on their particular bike.
Even Ducati have suggested (I make it no stronger than that as nothing in MGP is guaranteed, so fine is the line between success and failure)that a special tyre might give an answer to their problem. Simply saying Ducati were winners when special tyres were available is unlikely to be relevant as things have moved on.
How close the margin is was evidenced last year by HRC. +3kg and a softer sidewall/compound and the superlative tyre went from that to a pain in the proverbial.
If you are lucky enough to make the right choice on design the tyre will work as well/better for you than the competition. Then it's superlative.
However, if you are >1/10th per lap off that pace then it's an unmitigated disaster. If any other component is such a failure you can change it. if a rider doesn't like a suspension component (or chassis) he can change it. Tyres are probably the most 'psychological' component on a bike. Why is being forced to use the same tyre as everybody else fair? Limit the quantities, make them deliver tyres the week before (i.e. once a reasonably accurate weather forecast is known. I did like the overnight tyre aspect though), or whatever else 'cost savings' are really necessary to avoid one team having an unfair advantage on budget or technology. From my armchair the experts should be able to sort that out, and admit that the single tyre rule was a worthwhile, but failed, experiment. Just like 800's.