Marc Márquez Starts Strong in Grand Prix of Thailand

Winner after intense tire drama was Lenovo Ducati Racing’s Marc Márquez, with brother Álex on a Gresini Duc second and teammate Francesco Bagnaia third. Returning from obscurity in fourth was VR46′s Franco Morbidelli, who found new speed during the event.

That completes Ducati’s top-four sweep and Marc Márquez’s return as the dominant rider. Ducati is the professionals, with Marc topping qualification, the sprint, and Sunday’s GP.

The rest of the field consists of bikes and riders who cannot consistently perform at top level in all three contests.

There are Ai Ogura and Marco Bezzecchi, fifth and sixth, showing Aprilia’s promise but doing little better than the sixth, seventh, and eighth that a few years ago seemed to be Ducati’s lot in life, race after race.

In seventh was intense, quiet Johann Zarco, on Honda, showing some return to capability after a long time in the wilderness.

Eighth and ninth were the powerful, occasionally successful KTMs of Brad Binder and Enea Bastianini. The KTM company has passed a milestone in debt management and has stabilized.

In 10th, Fabio Di Giannantonio, VR46 Ducati.

Somehow, some way, Jack Miller qualified his Yamaha fourth but anyone hoping for something similar on Sunday had to be content with 11th. Former world champion Fabio Quartararo, also on the Yamaha, from which so much is expected? Fifteenth, speaking as he has many times before of lack of rear grip.

Those who yearn for a moment of weakness from Ducati or a surprise moment of strength from any other make are disappointed. If the others knew “the system,” they’d use it. To get on the system, you must provide three strong setups:

What was Marc Márquez’s “intense tire drama”? It was no problem to lead the race, but he saw his front tire pressure falling toward the minimum specified by Michelin. The rule requires that tire pressure must be above Michelin’s set point of 1.8 bar (or 26.5 psi) for at least 60 percent of the laps, and his screen told him he had already completed seven laps below that pressure. He had to get his front pressure up fast.

Dropping back to second behind his brother, he saw a gratifying rise in pressure from the heat of Álex’s slipstream. In practice, Marc had found three styles that could give the required lap time; now he chose the one best able to maintain front pressure. On lap 23 of 26, he passed his brother and won by 1.7 seconds.

What are these tire pressure rules about? Left to their own devices, race teams discover through experiment what tire pressures give quickest lap times, and they would like to use those pressures unless there’s a compelling reason not to.

The lower the tire pressure, the more heat-generating rubber flex occurs, and the hotter the tire runs. At some high temperature, the tire may blister as the most volatile component in the tread compound generates gas pressure that may erupt, leaving small craters in the tread surface. Blistering has most often been seen at Daytona, where not only are speeds high, but tire loading is increased by the 31-degree banked oval turns. Most feared is chunking, in which the bond between tread material and the tire’s fabric structure weakens, eventually allowing chunks of tread to be thrown off. Barry Sheene’s 1975 accident at Daytona resulted from such an event.

The view of riders and teams is that if lap times continue to improve as tire pressure is reduced (increasing footprint area), they naturally want to pursue that trend to its peak (which is well above a pressure so low that excess carcass flex produces directional instability). But what if a minimum pressure has been imposed by the tire manufacturer? Ideally you’d run the tire right on the minimum pressure. Because that’s too risky, you choose a higher pressure, but how much higher?

Each MotoGP bike now carries a sensor package in each wheel, reporting pressure and, perhaps, temperature as well.

If we start at too high a pressure, in hope of not falling below the Michelin minimum, we find tire grip falling as tire footprint area decreases at higher pressures. The first symptom is wheel locking during braking. Marc Márquez 12 years ago described what happens next. As pressure rises further, the tire “becomes hot and bouncy,” and if the rider doesn’t rest the tire for a lap or two, there will be no saving it. As the footprint shrinks, locking and sliding become more frequent, generating more heat, so pressure rises until the tire is useless. This is why there can be no “jist goin’ fer it” in MotoGP. Without the grip conservation that comes from thoughtful tire management, all is lost.

Race teams archive data, tempting them to write software to predict the tire pressure, but such predictions must have an error bracket: What if cooler or warmer air blows in? What if clouds dissipate to let in powerful sunlight?

Here’s The Big Question: Why would experienced tire engineers design a tire whose best lap time occurs at a pressure that makes decision-makers uncomfortable? We have the Daytona 2009 example before us, when reportedly the Speedway’s lawyers determined that above 180 mph on that 1960s track the risk of tire failure was unacceptable. As a result, the Daytona 200 ceased to be a 1000cc Superbike event, and slower 600s were put in their place. Could it be that race tires are in important respects designed by lawyers?

Every year when the preseason MotoGP tests run, we hope the half-fast teams have found something that will enable them to challenge the establishment. Ducati, by abandoning cherished errors and widening the performance envelope of its bikes, bootstrapped themselves to the top from its usual sixth, seventh, eighth. Once there it developed a series of new technologies that make it difficult to dislodge it. Any team would do the same, if they knew how.

Prior to this, Honda and rider Marc Márquez had been MotoGP champions six times in seven seasons. Surviving his “time in the wilderness,” he has earned his way back onto a dominant factory team’s bike—a tremendous accomplishment.

Any of Ducati’s rivals could notionally come up with improved performance or wider capability at any time. We hope they will. Ominous, however, is Marc’s description of his laps before the pressure warning: “I was cruising, and already I had opened a gap (1.353 seconds by lap 6).”

Where was Bagnaia, now teamed with Márquez on Ducati? He reckoned he had not gathered enough data early in the weekend to make an informed tire choice that would make him fully competitive. This is unlike him, for we all remember the many times he has said he can rely upon his crew to find a solution.

Jorge Martín (Aprilia), the present MotoGP champion, is recovering from injuries. The season begins with questions, and outcomes gradually provide the answers. We are hungry for them.