2023 Silverstone MotoGP Report

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Aleix Espargaró put all of the right pieces together at Silverstone to earn just his second MotoGP victory. (Aprilia/)

Our expectations of Aprilia came true this weekend with Aleix Espargaró's Sunday win at England’s fast Silverstone circuit. But given wet weather and the special nature of that track, which lacks many opportunities for lower-gear acceleration, the win cannot be seen as a change of status for the Noale factory.

Other riders commented that Aprilia goes well at Silverstone, and that rain—most especially mixed conditions—produces unique results. Some riders are known for their rain performances, while others are cautious.

“I’m very happy to be back on top,” Espargaró said, before commenting on hurdles that prevented him from taking a similar step earlier in the season. “I made too many mistakes and lost too many points. I’ve had good speed, many Fridays and in many sessions I was very close to Pecco, but it doesn’t matter. You have to be fast on Sunday.”

Francesco Bagnaia led a significant chunk of the British Grand Prix but suffered from reduced grip late in the race. (Ducati/)

This time he was, remaining near the front with obvious grip to spare and passing the leader, Francesco Bagnaia, on the last lap at turn 11.

“My plan was to overtake Pecco in turn 3, but in turn 2 when preparing the overtake, I did a highside and lost ground.

“I saw that Pecco had a lot less traction than me.”

Espargaró zeroed the gap to win by 0.2 second over Bagnaia (Ducati), with Brad Binder (KTM) 0.680 out of first. Fourth and fifth were Miguel Oliveira (RNF Aprilia) and Maverick Viñales (Aprilia), all within 2.1 seconds. Three Aprilias in the top five! Jorge Martín (Pramac Duc) was sixth.

Maverick Viñales looked strong in Silverstone. He finished third in Saturday’s sprint race, and fifth on Sunday. (Aprilia/)

Espargaró said, “There are days in my career when I felt I had something extra, that moment when I felt invincible. Sure, there haven’t been many, but today it was like this. I started well and then I easily reached Pecco’s tail. Then it started to rain. I lost confidence for a moment but then I saw I was strong.

“I had traction and I waited until the last lap to pass him.”

Bagnaia said, “We started with the soft tire because the conditions weren’t the best.

“Then it started to rain and I could not understand how much I could push.

“I tried to control everything and stay in front, but I saw that Aleix was with more traction and I was losing time in acceleration. I tried everything but it wasn’t enough.”

Thanks to journalist Alex Whitworth, Espargaró gave actual setup basics. “We made the bike a little bit shorter and quite a lot higher, to try to generate more grip, to…make the bike transfer [more weight to the rear].”

This is good old dirt-track science. In dirt track, grip is constantly changing. Riders know that when grip is falling, more weight must be shifted to the rear tire during acceleration, or the tire will spin rather than drive. Shortening wheelbase and raising ride height produce this shift. Remember this the next time you hear someone repeat ancient nonsense suggesting a low center of gravity is the key to handling.

Espargaró continued, “After qualifying we made the front even softer.”

Aleix Espargaró and some other riders, like KTM’s Jack Miller, were rather open about bike setup used in the wet conditions experienced at Silverstone. The move? Shorter and softer. (MotoGP/)

The stiffer the spring and damping, the greater the thump a bump delivers to both the bike and tire footprint. Therefore you run as soft as possible under current conditions, maximizing so-called “mechanical grip.” Normally softness is limited by the danger of bottoming the suspension or dragging hard parts on the pavement in midcorner. Rain changes this limit by reducing grip, which in turn means reduced cornering lean angle, allowing softer suspension to work without bottoming.

Always bear in mind that an increase in tire grip makes greater lean angles possible. The higher the lean angle, the more cornering force compresses the suspension.

Why not just increase suspension travel, as was done during the long-travel revolution that began in 1974? Because having 5–6 inches of travel front and rear (125–150mm) allowed bikes to assume exaggerated pitch attitudes, especially during braking. Therefore, beginning in the early 1980s, GP suspension travel decreased again—sometimes to as little as 4–4.5 inches.

A special problem of long front travel is that initial brake application can dive the front so fast that the bike acquires “pitch momentum” which when stopped unloads the rear wheel. The result can be tail-wagging (as seen in MotoAmerica’s King of the Baggers racing), or even snapping around, out of control.

Alex Márquez earned his and Gresini’s first-ever sprint victory on Saturday. (MotoGP/)

Jack Miller (KTM) finished eighth in Silverstone and was equally forthcoming. “I’ll say it. Our bike is 30mm shorter. When it goes from dry to wet we are 30mm shorter, which is a massive step on a MotoGP bike. But it seems to work like that.

“If it’s not completely wet (rain came near the end on Sunday), we don’t need all that [weight] transfer.

“It was like it was almost overloading the rear and that was what brought the rear [tire] temperature through the roof from the beginning.

“I was suffering for grip and just couldn’t get it working from the start.”

Conditions in FP2 recalled 2018 when on the repaved surface poor drainage allowed pooling of water on the circuit—enough to produce aquaplaning. Oliveira said, “Should there have been a red flag in FP2? Yes, for sure.

“With those crashes where you aquaplane, you do once the corner in the same speed and you don’t crash. And the lap after, the bike just spins on you for no reason.”

Power brushing removed some of the accumulated water.

Aquaplaning is a special case of a plain bearing, in which the rolling object is a crankshaft journal surrounded by oil. When there is too little time for the liquid to be pushed out of its way, the journal (or tire!) climbs onto the liquid and friction drops nearly to zero.

Enea Bastianini, Marc Márquez, and Fabio Quartararo struggled on Sunday. Bastianini ultimately crashed out after coming into contact with Márquez. (MotoGP/)

With Honda and Yamaha out of contention, MotoGP continues as a European series. In Saturday’s sprint race Franco Morbidelli’s Yamaha was the highest-finishing Japanese bike, in 15th place. Joan Mir’s Honda was 17th. In Sunday’s GP, 14th through 17th places were taken by Japanese bikes.

Takaaki Nakagami (LCR Honda, 16th) said, “For us it’s like there is too much safety.”

He explained that engineers had adopted a strategy “to be more safe” in electronics settings as a result of some big high-side crashes.

Fabio Quartararo said Yamaha’s new “big aero” fairing was “interesting” but put it aside, explaining that extra engine power is consumed in generating the downforce that can allow increased acceleration without wheelies. In later races, on tracks with more lower-gear acceleration, Yamaha may benefit from such a fairing.

Marc Márquez was referring to just this benefit after losing one wing in a first-lap contact with another bike. He said, “Without one wing I was losing a lot under acceleration.”

Quartararo lost his front fairing after coming together with Mooney VR46 rider Luca Marini on Sunday. (MotoGP/)

Supposedly the new minimum tire pressure regulations and penalties went into force at Silverstone, but on a random basis. Luca Marini (VR46 GP22 Ducati, seventh) said, “I understand from the tire when the pressure is higher than 2 bar (29.4 psi), given that they start to lose performance, causing me to lock up more at the front and close in midcorner. In my opinion the target is too high.” Michelin requires a 27.6 psi minimum.

This is the problem for riders, who know from experience that lower pressure increases footprint area, with a useful increase in grip.

Marini seemed resigned to such things. “Maybe we can change something for next year,” he said.

A consideration for any tire maker supplying racing tires is avoiding negative publicity from an on-camera tire failure. The lower the pressure in a tire, the more it flexes under load, and the greater the heat generated. If an especially hard-worked band of the tread becomes hot enough, the result can be blistering or even chunking.

On the other hand, the race sanctioning body knows that viewers want to see races won on the track and not by rule book lawyers arguing over when a certain tire pressure sensor was last calibrated, and by whom.

Isn’t it embarrassing for the tire maker to publicly show such limited confidence in their product?

Brad Binder fended off a hard-charging Miguel Oliveira for the final podium spot on Sunday. (MotoGP/)

A published interview with Aprilia’s race tech chief Romano Albesiano by Matt Oxley in Motor Sport throws a little light on a long-standing handling problem: the effect of rear suspension geometry on corner entry.

We know that in the early 1990s progressive teams discovered that by correctly setting the height of the swingarm pivot, the old problem of squat-and-push during off-corner acceleration could be controlled. But what about the effects of reverse chain tension and engine-braking on rear suspension during corner entry? On another occasion Albesiano referred to the few lines of software used to soften the “clunk” as the rider begins to move the throttle, taking up the backlash in transmission engaging dogs.

Front and rear suspension spring balance is set in practice, but for what condition? Entry? Midcorner? Exit? A best compromise all the way through may gain you a tenth. A tenth in half of 10 corners, times 25 laps is 12.5 seconds at the flag. Adjustments to engine-braking, aero downforce, and use of the rear brake all have effects here. Aprilia’s tail-mounted, T-shaped wing was said to have had a surprisingly strong effect. On what? Near the limit, small effects are magnified.

Haven’t we been hearing for years about mysterious problems with rear grip during braking and in corner entry? Albesiano revealed little other than his interest in this area. Time for some digging.

Now with half the races yet to come, the championship points are as follows:

1. Bagnaia - 214
2. Martín - 173
3. Bezzecchi - 167
4. Binder - 131
5. Zarco - 122

Will Bagnaia increase his advantage in coming races, as appears likely? Or can a David arise from the ranks to challenge Ducati’s Goliath?

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