The highlight of the weekend came on Sunday when Ducati's Marc Marquez made his pass on Aprilia's Marco Bezzecchi to lead from lap six. They drag-raced down the straight, where top speeds of 218 mph were recorded.

Bezzecchi said, “When we went close to each other in the straight, the air was like doing something strange. I wanted to move away from him but sometimes I was coming closer.

“Then I was a bit too much on the left, so I had to brake a little bit earlier and in that moment Pedro came from the right with a good amount of speed.

“Unfortunately I lost {two} places. But it was a fun moment.”

Marc said, “It was an incredible moment. Because with all the aerodynamics, at 300 kph our bikes were being sucked towards each other.
“Then arrived a point where Marco gave up a bit because he was on the dirty side.
“As soon as I led the race, I tried to manage the pace. When ten laps remained, I pushed a bit, opened a gap, and controlled again.

Side-by-side at 218 mph. Old Bernoulli noted in 1738 that the faster air moves, the lower its pressure. High velocity airflow passing between the bikes naturally created a partial vacuum there.

Marc Marquez’s 1.74 second win at Aragon illustrates the extent to which MotoGP bikes and riding styles remain specialized for certain tracks and conditions. At Silverstone, pundits were declaring Aprilia now dominant.

Dirt-track racers have told me that corner-speed can work on dirt so long as there is reliable grip. But when grip becomes spotty it’s necessary to fall back on the inherently safer point-and-shoot style.

Why? A rider using corner speed is gambling that grip will be adequate to sustain the desired trajectory all the way through the corner. If such grip is present, races can be won that way (think of Jorge Lorenzo). But in point-and-shoot, grip is mostly under rider control – braking on the way in, throttling-up on the way out. The speed at the apex—what Cal Crutchlow has described as a V-shaped line—is low, but is so-placed that the rider has room on exit for rider-modulated acceleration to make up for it. Kenny Roberts emphasized that point-and-shoot is inherently safer when grip is limited – because it allows the rider to control how much grip is used (rather than committing to a certain line and entry speed, as with corner-speed – gambling that the grip to which your entry speed commits you is actually present).

Grip at Aragon was poor as a result of dust carried onto the track by wind during dry weather. The upper apex of the usual Saharan dust was just touching southeast Spain – not guilty.

Pedro Acosta (2nd, factory KTM) said, “Without the hard tire I don’t have any grip on the front. (Michelin didn’t bring the hard)

“It’s true that it’s a bit dirty; when you are behind somebody in the back straight, it’s like [a lot of] sand coming up.”

As the front tire pushes air aside, its rolling creates a low pressure behind it, so air rushes in. This scours dirt up from the pavement texture.



Similar conditions have existed at Qatar and Barcelona—with fine dust in the pavement texture, the molecular adhesion aspect of tire grip is partly lost, making it easier to slide, spin or lock the tire. Such increased sliding accelerates the fatigue suffered by the high-grip rubber at the tread surface (sometimes a manufacturer may employ harder rubber under the “grip layer” to reduce heat generation). The result is poor grip and early tire drop.

The hard front of last year was better able to retain its grip despite the special Aragon condition.

Another point, and one not often discussed, is this: on the basis of which sensory data—possibly not consciously received—does the rider lose confidence? In a famous example, Loris Carpirossi felt that his Ducati was “moving around” (i.e. possibly about to lose grip and with it, control) when in fact it was the flexibility of the bike’s footrest brackets.

It seems possible that at least some of Bagnaia’s plight at present may come from something similar.

During the flamboyant racing career of Yvon DuHamel, his team would watch his sliding and wobbling progress around the circuit, then hear him say, upon returning to their pit, “I t’ink it’s maybe a bit better now.”

Yvon was comfortable with both tires sliding. Not all riders are.

Think also of Ben Bostrom, whose bike was always loose, swinging lazily from side-to-side during hard braking, as if at any moment it might switch ends (this has been known to happen). He was comfortable in that state.

Marc Marquez also won the Sprint (maximum possible points catapulted him to 2nd in the championship this weekend), and in doing so demonstrated his valuable experience base. Marco Bezzecchi (3rd on Sunday, factory Aprilia) had set a new lap record that Marquez couldn’t upset, running wide disrupting one attempt, then having to make an elbow save during his last try. Riders keep in mind the important difference between the one-lap speed of qualifying, and race pace.



Marquez Saturday morning had gone out to check the usability of the soft rear. As he suspected, it grained as it had at Silverstone.
“…if you start to have that graining, you lose half a second, one second per lap.”

Visually, graining seen from the rear is abraded-off rubber that has re-adhered to the tire as U-shaped lines or beach marks – edge to edge. Today it is associated with insufficient tensile strength or failure to reach operating temperature.

He said, “When I saw that Marco was starting with the soft, it was the only chance, to attack at the first corner.”

If he failed to take the lead, he would risk fatiguing his medium in the ensuing contest, and risk overheating his front in Bezzecchi’s hot draft.

He continued, “I know that it’s a corner where I feel strong, and then when you lead the race, you can control {the pace}.”

How was he able to pass Bezzecchi on Sunday and remain out of reach of the dynamic Acosta to win? Having found his injured arm near-useless at the end of Silverstone (big discussion at Ducati), he announced before practice began that he would in future conserve energy on Fridays.

Another view of conditions came from Fabio Di Giannantonio (P7, VR46 Duc). “Right from the start I had a really bad feeling about the rear.”

Noting he almost never complains about the rear, he said. “{after the Sprint} it felt like I was riding on ice. After two or three braking zones where I was braking normally, I found myself completely sideways. I’d go into the corner all crooked, the bike wouldn’t stop, and as soon as it regained a bit of grip, it would carry me wide, and eventually I lost the front.”



Sunday’s race was harder work for Marquez than the Sprint. This time, he said, “I did a huge mistake today because I forgot the rear {ride height} device. And then when I went out from turn 1 to turn 2, the rear device was activated and loaded again.”

Two riders passed him. “…from that point I just built the pace and it was a nice fight on those first laps.”

He led from lap 6 to the end.

Not enough passing? Acosta added this: “If you stray even slightly off the ideal line, you’re immediately at the limit,” meaning that there was only one clean line. In the Sprint Marc and brother Alex finished 1-2, a second apart. With his front tire pressure rising (the next step is usually locking) Alex wasn’t able to contemplate passing him.

Jorge Martin (5th, factory Apr, and points leader) said, “After Silverstone (where he’d been 2nd)…I expected maybe to fight for the podium, but Friday already I saw that I couldn’t.

“The grip overall was my limit during all the weekend.

“…top-five was the maximum and I took the points (he still leads the championship by 19 points but it is now Marquez in 2nd, instead of teammate Bezzecchi).

Acosta is notable for being far ahead of the other KTM riders. Bastianini, when asked where and how Acosta achieves this, said, “Confidence in the front …plays a role. But there’s also the matter of being able to release the brake.

“In the final part of entry I keep the brake on until the very end, then I go straight onto the throttle. He, on the other hand, has that phase where he manages to release the brake and let the bike go. He’s very good at that.”

Holding the brake detracts something from turning – the front tire can only give so much (Google “The circle of traction”). Acosta may hold line better doing this, and he may have developed a set-up that cues him when the cliff‘s edge is near. So much is not seen.

What’s fascinating in these races is Marquez’s ability to take points from talented younger men on competitive machines. Race-long duels like those made legendary by Giacomo Agostini and Mike Hailwood were only possible because nobody was third and closing. In today’s circumstances, riders avoid such duels because their slowing effect makes opportunities for close pursuers. And so races often come down to a brief period of push-and-shove for position, followed by the winner being the one with the fastest race pace. A dominant aspect of that pace is understanding what the tires are saying.

Misano is next – Sept. 11-13Jorge Martin 256
Marc Marquez 237
Marco Bezzecchi 232
Fabio Di Giannantonio 208
Ai Ogura 203 (absent this weekend)