until Abu Dhabi Autonomous Racing League


Why Yamaha is giving both its MotoGP riders arm pump

by Valentin Khorounzhiy
5 min read

until Abu Dhabi Autonomous Racing League

Three years ago, a likely Spanish Grand Prix victory for Fabio Quartararo went begging when he slowed dramatically with a severe case of arm pump - which led to surgical intervention after the year, and ultimately wasn't enough to derail his run to the 2021 MotoGP title.

But arm pump - a condition officially known as Chronic Exertional Compartment Syndrome, which describes muscles swelling up and having blood flow cut off as a consequence - struck him and Yamaha again at Jerez three years later, not as severely but also with not anything like a win at stake.

And what will be disheartening for Yamaha to hear is that this time it affected not just Quartararo but also team-mate Alex Rins - and that both pointed to the bike as the culprit.

The M1 didn't have the most competitive of weekends at a track where it used to shine, although Quartararo did mount an unlikely podium bid in a sprint race of ludicrous attrition - before this was overwritten by a post-race penalty.

On Sunday, both Quartararo and Rins were more around where they'd been expected to be - albeit with Rins in 13th getting a currently-rare edge over Quartararo as the latter spent the last few laps, per his description, "cruising" due to the arm pump.

"It wasn't a surprise," Quartararo said after taking 15th. "It's happened many times this year. But it was never really a limit.

“When you feel good on the bike, you don't have it. When you feel not alright, you have it. And in some races I had it - but not that much and not that early. But it's part of our challenge."

Quartararo effectively rolling off  - going into the 1m40s range in his final lap - meant he finished 3.5s and two places behind Rins, except Rins himself had also felt an onset of arm pump while shadowing Quartararo during the race.

"When he started to gain some tenths [on me], it's because I was done,” Rins said. “But then, I don't know from where, I took some power, some strength, and I was able to catch him, I maintained the laptimes.

"But yes, it's since the first race in Qatar that I'm having problems with the arm pump."

Rins has had arm pump surgeries of his own in his career, but the bigger commonality here is the bike - with both riders emphasising just how much they are having to force an M1 they currently see as unruly.

Once seen as the go-to bike on the grid in terms of rider comfort, the Yamaha has lost all of that according to Quartararo - and Rins has largely concurred since his arrival after having previously raced the Suzuki and the Honda in MotoGP.

"It's so difficult to turn the bike," Rins said earlier in the Jerez weekend. "Maybe it's coming from the engine, from the inertia... we don't know exactly. What is true is that we're struggling a lot.

"We are exiting [corners] not on the correct line, so... we can't prepare the next corner. And everything is more difficult."

He provided an example later in the weekend: "Like, exiting from Turn 4, we are out of the line to prepare the next corner. Exactly the same happens in Turn 8, Turn 12. Turn 12 is a high-speed corner - when the others are braking straight and then going left [for Turn 13] we start to brake [leaning] on right, then we brake [leaning] on left, then we go in."

All of those corner sequences are fairly fast changes of direction, physical at the best of times - and they proved too physical for both riders on Sunday given the state of the M1.

"I try to give my maximum, you know," said Rins. "When the bike doesn't work in the best way, I try to supply [compensate] with my riding style, the way I know. But it's difficult, it's tough.”

Quartararo also suggested he'd exacerbated the arm problem with some changes on the bike in that day's morning warm-up.

But he described the Yamaha overall as "much more aggressive".

"When I have to turn, I have to pull the bike a lot. It [the arm pump] is not what I really expected, and not that early in the race.

"I had Pedro [Acosta on the Tech3-run Gas Gas-badged KTM] and Aleix [Espargaro on the Aprilia] in front, I tried to fight with them, but I could clearly see the difference. I think it's great information, for the few laps I could see.

"This is one of the tracks that I think is right now one of the worst for us - because the turning is our weak point, with the grip, and in this track you need both. I expect Le Mans to be better, because it's more about braking, and I will feel better on that track."

Both riders were in good shape to conduct a productive test day on Monday following the race - logging a combined total of 157 laps and trying a variety of items including a new aero set-up, a new chassis and a new swingarm.

Quartararo found the "really different" chassis a slight improvement in terms of corner entry and front feedback, while Rins felt it may be a bad match for his riding style.

And as for the aero - which Yamaha was hoping to homologate for racing soon - both went down the middle with their comments.

"When you look at the bike with this new fairing, it looks spectacular. The numbers on the windtunnel are so different, very different. But on track, I was expecting a little bit more," Rins said, despite then suggesting a tangible gain of around 0.1-0.15s.

Both, however, indicated that Yamaha's turning problem - the thing that made their arms swell up in the Spanish GP - was nowhere near being solved.

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