MotoGP

Analyzing the MotoGP Michelin Tire Test

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The departure of Bridgestone and the arrival of Michelin as the official tire supplier to MotoGP is an extremely delicate operation, in terms of marketing, tire development, and motorcycle set up.

Bridgestone have paid a lot of money for the exclusive rights to MotoGP branding with their tires for 2015; Michelin have done the same for the rights from 2016 onwards.

Neither company wants to tarnish their brand or see the value of their investment diminished, either by rider comments expressing a preference one way or another, or by lap time comparisons showing either firm up.

This posed problems for the Michelin test, held on the fourth day of the Sepang MotoGP test. After the factory test riders had tried the Michelins at the first Sepang test, it was the turn of the MotoGP regulars.

To avoid any comments which might favor one factory or another, Bridgestone imposed a blanket ban on riders or team members speaking to the media after the test.

All Bridgestone branding was removed from bikes and leathers, and no visible Michelin branding was allowed, even down to the manufacturer’s logo on the tire sidewalls.

With major money on the line, the PR gag-order was enforced rigidly, and observed religiously. No official times were released, nor made unofficially available by the teams.

A range of times have seeped out from journalists present, but given that only a few laps were timed by a few people out of practice with using a stopwatch (or its modern equivalent, the smartphone), those times can be taken as guidelines only.

Perhaps the biggest problem was posed by the requirements of tire testing. The riders have just completed three days of testing, building speed and confidence on their 2015 bikes with the latest generation of Bridgestones.

They have put in a lot of laps in extreme heat, and are running out of reserves of energy, despite their almost superhuman fitness levels. Their minds and muscle memory is completely attuned to the Bridgestones, so putting them onto a different tire with different characteristics poses a major risk.

The riders are focused on pushing hard, and expecting a particular feel from the tires, front and rear. It is potentially a recipe for disaster.

And so it proved to be. Several riders went down heavily at Sepang on Thursday, destroying some expensive machinery in the bargain.

Jorge Lorenzo and Andrea Dovizioso crashed in Turn 3, a fast and furious corner; Jack Miller and Aleix Espargaro fell at Turn 5, where the track drops away.

Damage was extensive, Lorenzo’s bike being almost completely written off, and Dovizioso’s Ducati GP15 – the only one at his disposal – getting properly knocked about.

As the two riders who crash least in the paddock, that Dovizioso and Lorenzo should go is rather worrying, and points to a serious problem. But then at this stage in tire development, that is exactly what is to be expected. Fortunately, everyone walked away from the crashes, though the same could not be said of their bikes.

Michelin had brought a fair stack of tires for the riders to test. They were given four different front tires, and three different rears, with a focus on construction and profile rather than compounds.

Compounds, Michelin boss Nicolas Goubert told Speedweek, will come at a later stage. For the moment, it was important to get the basic shape, strength and construction of the tires right.

Tire sizes are all 17-inch, rather than the 16.5-inch tires used until now for the Bridgestones. The reasons for this are simple: Michelin feel the knowledge gained from using a standard size used in road tires will transfer more directly into production. Though the tire sizes are different, the outer diameter is exactly the same, the difference coming in the height of the sidewall.

The tires used at the test are more or less the same as Michelin have been testing since late last year, though they did bring a different profile for the front tire to the test. The old tire was more of a V shape, while the new tire is more rounded. The V profile was more agile in turning, but the rounder profile was more stable in braking. According to Michelin, the riders overwhelmingly preferred the new, rounder front.

Michelin told Speedweek that the general feedback was that grip from the rear was good, but this was causing problems with the front. This appears to have been the cause of the crashes, with all four crashes coming as riders get on the gas and start pushing the front.

Finding they have more grip than expected at the rear, the riders start opening the throttle earlier and more each lap. At some point, the drive from the rear overwhelms the grip from the front, the front tire pushes, then lets go, and the rider goes down. Michelin attributed the crashes to an imbalance between front and rear grip.

Does this mean that the Michelins are inferior to the Bridgestones? Not necessarily. Normally, once the front starts to push, then a crew chief would start to modify setup, changing weight distribution, geometry, wheelbase to transfer grip from the rear to the front. Eventually, such changes would get passed on to the factory engineers, who will modify their designs to accommodate the different balance of the tires.

But this is not possible at the Michelin test, as the aim of the test was to evaluate tires, not chase setup. The first rule of testing, as in all forms of engineering and science, is to change one variable at a time.

If the goal is to assess the performance of various tire construction and profiles, you leave the set up unchanged, and switch tires. Only then do you get a usable and consistent set of data. Track conditions might change as a result of the heat, but that is not a variable which you can control for. Everything else needs to stay the same.

The result was that Michelin got the data they need, but at a cost. They had hoped to avoid embarrassment, but broad coverage given to the crashes – the only thing the media were allowed to report on – do not make them look good.

Because of the media blackout, the circumstances of the crashes are not being taken into account. Crashes were frankly inevitable, with tired riders chasing fast times, using a setup that had been optimized for a different brand of tire. There was no opportunity to work on the balance of the bikes or improve setup to handle the different characteristics of the Michelins, because the aim was to test tires, not setup.

Are Michelin to blame for the crashes? That would be very unfair. Michelin needs to test with the factory riders, and they need to test as early as possible, to be ready for 2016. But scheduling a time and a place to do that testing is difficult and costly.

Flying all of the teams to a circuit, with all of their equipment, then giving the riders a day or so to get up to speed would be expensive, so running the test on the last day of the Sepang test is a logical choice. Not necessarily a good choice, but one of the least-worst available.

So what of the times being posted? Nothing official is available, and the different media outlets who were present failed to work together to produce a more reliable list, meaning that different sources show different times.

Broadly, the times are comparable to those set on the Bridgestones, with Marc Márquez and Andrea Dovizioso posting 2:00.1 laps, Valentino Rossi, and Jorge Lorenzo clocked at 2:01.0, Dani Pedrosa on 2:01.5, Cal Crutchlow and Pol Espargaro doing high 2:01s, Bradley Smith low 2:02s. Marc Márquez and Valentino Rossi did a couple of long runs, the pace averaging somewhere in the 2:01s.

What do any of those times mean? It is hard to draw firm conclusions from the times available. They were recorded by hand, and unlike at an official test with official timing, only a handful of laps were timed.

There is not a complete list of every lap posted, to give a sense of what a race pace might be, and to draw up an order. But the times recorded suggest that the Michelins will be competitive with the times set on the Bridgestones, which is exactly what you would expect. Michelin will have used those times as a benchmark to beat. If they don’t do that, they will look bad.

The results of the test also underline that different tire manufacturers have different concepts, and that these concepts remain unchanged over the years. When Michelin left MotoGP, their tires were praised for having masses of rear grip, but lacking the ultimate grip of the Bridgestone fronts. The spate of front ends washing out suggest that little has changed since 2008.

This also highlights the changes that will need to happen for 2016. Setups will change, weight moving forward to assist front end grip, and create a better balance between front and rear. Riding styles will change too, riders moving their faith from the front tire to the rear, and using that to control the bike a little more.

All these changes will make their way back to the factory racing departments, where engineers will try to improve mechanical grip front and rear.

Modified frames and swing arms will travel back and forth between track and factory, in search of the best compromise. Suspension companies will pore over data, modifying internals to accommodate the different damping characteristics.

In other words, it is all going to cost an awful lot of money. Changing tire manufacturers is by far a bigger deal than the introduction of spec electronics. There will be winners, and there will be losers, some factories will get it right, and some will get it wrong, and take time to catch up again.

My own personal thoughts? Don’t bet against Honda. With the most money, the best brains, and the best rider in the world, they will surely be the factory to beat.

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