Jack Miller weight loss: “It feels like I'm in Moto3 again!”

Already the smallest of the Yamaha MotoGP riders, Jack Miller has shed a further two kilograms ahead of the 2026 season.

Miller’s not the only Yamaha rider looking lean during winter testing, with Monster Yamaha’s Fabio Quartararo also appearing thinner than before.

Unlike the Moto3 and Moto2 classes, which use a combined rider and bike minimum weight, MotoGP only specifies a minimum machine weight (157kg).

Therefore, any reduction in the weight of a rider is a potential performance advantage in terms of reducing mass under acceleration and braking, plus frontal area for aerodynamic drag.

However, it must be balanced with having enough strength and endurance to ride a MotoGP bike at the limit for a grand prix distance.

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Marc Marquez certainly looked visibly thinner ahead of his title-winning season at the factory Ducati team, which may have prompted others to try and follow suit.

According to the size and weight stats on the official MotoGP website, Miller is now equal with Marquez at 64kg, despite the Australian being four centimetres taller than the Ducati rider.

At the Buriram test, Jack Miller confirmed he had lost “two kilos” over the winter.

“I started working with a different trainer at the end of last year, December,” he explained.

“It’s been good. I’ve been enjoying the process, just working with a different outlook. I’m an old dog, but it’s never too old to learn new tricks!”

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“It’s was mainly just the way of training,” he added. “Not massive, but a little bit different, more consistent, a little less high heart rate stuff. A lot more controlled, let’s say. A lot more strategic with the training.

“And then diet as well, just trying to eat as clean as possible, especially over the winter.”

“Feel like I’m in Moto3 again”

Although Miller didn’t explicitly confirm that the weight loss was prompted by the lack of top speed from the new Yamaha V4, Miller did joke about “feeling like he’s back in Moto3”.

“I’m trying to get myself in the best shape possible, and I feel the fittest I’ve ever felt coming into a season,” he said. “Losing weight as much as possible to feel like I’m in Moto3 again, trying to make the bike as fast as possible!”

Any extra km/h on the straights will certainly be welcome, with all four Yamahas at the bottom of the speed charts during the final afternoon of pre-season testing.

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2026 Yamaha MotoGP riders: Size and weightJack Miller: 173cm, 64kgAlex Rins: 176cm, 68kg.Fabio Quartararo: 177cm, 69kg.Toprak Razgatlioglu: 185cm, 80kg

Jack Miller, new Yamaha wing, 2026 Buriram MotoGP Test (Gold&Goose).

Aero? “The team were scared after last year!”

In terms of Yamaha’s aerodynamic package for the start of the new season, Miller revealed that the new aero was the “clear choice” and that the old tri-plane design had only been seen on track to ensure enough parts for this weekend’s season opener.

“It was clear anyway we were going to be on that [new design], we were all, I think, unanimously happy with it in Sepang,” he said.

“The only reason I was not using it [on day one at Buriram] was for parts. So we are in the process now of building enough up, but, you know, the team are scared and rightfully so after my season last year…! They know we can chew through some spare parts.”

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“A difficult one for us with so many big straights”

Miller finished the test as the top Yamaha rider in 16th place, 1.004s behind Aprilia’s Marco Bezzecchi.

While Yamaha appears braced for a difficult start to the year on the underpowered V4, Miller put a brave face on the situation.

“Happy enough with pre-season, obviously it’s been busy. Today it was f**king busy. Two long runs… I’m gonna sleep like a baby tonight. But that comes to the territory with the new motorcycle, trying to understand it, trying to develop it,” he said.

“We have clear areas we need to work on, but I feel good on the bike, feel like it’s getting better – working on it, changing little bits here, there and everywhere.

“So looking forward to going racing. Obviously, we know this track is going to be a difficult one for us with so many big straights.

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“We have a clear plan for when the first updates are coming. So the boys are pushing hard, and I’m pushing them harder to, let’s say, shorten the process as much as we can.

“But apart from that, handling-wise I feel not bad. I’m enjoying riding.”

Jack Miller, old front wing, 2026 Buriram MotoGP Test (Gold&Goose).

Yamaha V4: One-second, six months “no small feat”

Told that Quartararo appears less optimistic about the new bike, Miller responded:

“I try to be as positive as possible, and we have, like I said, a clear plan on when updates are coming. I firmly believe that the engineers are working their hardest.

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“To have a motorcycle that was basically built six months ago, only one second off over one lap is no small feat. It takes a lot to reinvent a motorcycle.

“So the engineers are doing a good job, and we will continue to push to try and give them the best feedback as possible and keep working the best that I possibly can.”

The first engine upgrades are not expected until the start of the European season.

Jack Miller, Toprak Razgatlioglu, Sepang MotoGP test.

Razgatlioglu “will get there”

On the other side of the Pramac garage, star rookie team-mate Toprak Razgatlioglu was left at the bottom of the timesheets, 2.1s from Bezzecchi.

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“Ah, he’s working hard. He’s a multiple-time world champion, but at the end of the day he’s a rookie and these tyres, this bike…” Said Miller, who has been trying to assist Razgatlioglu on and off track during winter testing.

“If he was coming in on a bike that is running at the front, then of course he would expect more. But unfortunately for him he’s coming in on a project that at this point in time we are building.

“He will get there, I tried to help him as much as I can with a tow in the first long run and then a tow at the end of the day, much as we did in Sepang. I try to do my best to be a good team-mate towards him and try to help his transition.”

Opening practice for the Thai MotoGP takes place on Friday morning.

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Jack Miller weight loss: “It feels like I’m in Moto3 again!”

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