Vortex generators are all the rage in MotoGP, featuring on the latest KTM, Aprilia and Yamaha, so what do they do? Plus other developments spotted in the Buriram pitlane
Next year’s technical rules will reduce the amount of aerodynamic downforce at the front of MotoGP bikes, but they won’t reduce the importance of aero.
“For me, aero will be the key, from here to the infinity of MotoGP,” says factory Honda rider Luca Marini. “We will go much closer to cars, because if you play with aero it makes so much more difference than a new swingarm, a new frame or something like that.
“If you need grip, you can make a good job with the aero and you will have more grip. If you need more turning, and you understand how to make the bike turn with aero, you will find the turning. And with aero you can find more stopping power. Also, finding more power is difficult now, but if you have better aero with less drag, you will be faster at the end of the straights.”
Downforce aerodynamics have only been taken seriously in MotoGP for the last decade, whereas the science has been crucial to Formula 1 for half a century, which is why we are seeing more and more aero details appear on MotoGP bikes, as engineers delve deeper into the science.
Consider the vortex generators on the swingarm of KTM‘s 2025 RC16 (immediately to the left of the Akrapovič and WP stickers in the above photo). These aren’t MotoGP’s first vortex generators, but they are worthy of examination.
The KTM’s vortex generators are bonded to either side of the RC16’s slab-sided carbon-fibre swingarm. They are specially shaped 3D-printed vanes designed to reduce drag by accelerating airflow in specific areas. (Note the silver heat tape protecting the right-side VG from the exhaust outlet.)
The air flowing immediately over a surface – the RC16’s swingarm or more commonly a Formula 1 wing or aeroplane – is called the boundary layer. If this layer slows too much it stops flowing smoothly and breaks up, causing turbulence, which creates drag.
Therefore, the RC16’s swingarm VGs are designed to speed up airflow to reduce drag. The improvement will be tiny, but MotoGP is more than ever a game of marginal gains, so every little helps.
Aprilia RS-GP
Aprilia‘s aerodynamics department is currently the most go-ahead in MotoGP, so it was no surprise when the RS-GP’s fairing sprouted vortex generators at the start of last year.
While the 2025 RS-GP featured two VGs either side of the fairing, this year’s bike features three VGs either side (yellow arrows). Their function is to accelerate airflow across the fairing, to prevent the flow from breaking up and causing drag before it reaches the tail end of the fairing.
Aprilia’s VGs got much less attention at Buriram than their new F-duct (blue arrow), an idea borrowed from McLaren‘s 2012 Formula 1 car, which introduced the idea of the driver physically adjusting aero by jamming his arms into airducts that ran through either side of the car’s cockpit.
The Aprilia’s F-ducts start in the fairing nose, with two inlets funnelling air to cool hot-running electronics, and end through rubber gaiters at the top of the side fairing. At higher speeds the rider can jam his elbows into the gaiters to close off the ducts, thus reducing drag.
The RS-GP bristles with clever ideas like these, plus a chain guide (red circle), designed to prevent the drive chain jumping the sprocket. Aprilia were the first to run chain guides at the start of last season. Why have these guides become necessary? Because holeshot devices allow much more torque to be applied when the lights go out.
Marco Bezzecchi‘s dominant Thai performance was obviously worthy of praise, but his race time wasn’t that impressive: 1.1 seconds faster than Marc Márquez‘s 2025 winning time and actually 0.1 seconds slower than Márquez’s 2019-winning time.
During that same period, Mugello‘s MotoGP race time improved by 14 seconds and Jerez‘s by 12 seconds. So what’s up? Michelin has made two big rear-tyre upgrades since 2019 – the first in 2020, the second in 2024 – while the heat-resistant rear used at Buriram hasn’t changed at all. Also, race conditions were hotter than ever this year.
Ducati Desmosedici GP25
Marc Márquez’s Ducati Desmosedici GP26 looks pretty much identical to his GP25, apart from some cosmetic details – different paint (celebrating Ducati’s centenary) and more exposed carbon-fibre in the seat unit and dummy fuel tank.
Indeed the reigning champion has gone back to 2024 aero, after racing 2025 kit through much of last season. The 2024 aero makes the bike less physical to ride, an important consideration because his five-month-old shoulder injury is still causing him problems.
Márquez always feels better with used tyres – because he can find an advantage there – but more now than ever, once again due to his fitness.
“I feel much better with used tyres,” he said at Buriram. “This was already true last year, but now even more, because with used tyres the bike is less physical.
“I feel good but I’m not riding the bike like I want. In entry I don’t feel good, but this is more my riding style than the bike. I injured the front part of my shoulder, where I need to push more, so I don’t brake in a good position, so I’m also not in a perfect position in the middle of the corner.”
Team-mate Pecco Bagnaia had every reason to expect a great Thai Grand Prix – his sprint simulations at the Sepang and Buriram tests were very fast – but it didn’t work out like that.
“There’s less grip than at the tests, so Aprilia and KTM have the advantage in braking and entry,” he said.
But Bagnaia still believes the GP26 is better than the GP25…
“In braking and entry you can brake later and stop bike earlier, so it’s a good improvement for me… more stability.”
Does this suggest the friendlier inertia/engine-braking character of the GP24 engine?
Honda RC213V
Honda’s RC213V had the biggest year-on-year improvement in top speed at Buriram. That was no great surprise, because much of that improvement was already there at the end of 2025, when the RC213V was the fastest bike at a couple of rounds.
Compared to Buriram last year the RC213V was a massive 5mph/8kph faster, at 208.6mph/335.9kph. Honda was able to introduce upgraded engines last season, when they were in the D concessions rank. They are now in the C rank, so no more upgrades.
The Ducati was once again the fastest bike at Buriram, improving 2.9mph/4.6kph to 210.9mph/339.6kph, thanks to work on the intake and airbox. Engines are 2024 or 2025 spec, with no internal work allowed.
Aprilia improved 3.8mph/6.1kph to 208.7mph/336kph, while KTM improved 1.1mph/1.8kph to 207.9mph/334.7kph
Yamaha was the only factory to go backwards, their V4 YZR-M1 0.7mph/1.3kph slower than last year’s inline-four M1, at 204.8mph/329.8mph.
Although there’s no doubt the RC213V has improved significantly over the last 12 months the bike still has a way to go. Last year, its race pace was 0.59 seconds off the winner. This year, Joan Mir averaged 0.62 seconds slower than Marco Bezzecchi before he was sidelined by rear tyre problems.
KTM RC16
KTM left Thailand leading the MotoGP world championship for the first time, suggesting that the Austrian brand has made a big step forward with the RC16.
Reigning champion Marc Márquez wasn’t so sure.
“It’s not KTM, it’s Acosta,” he said.
In fact, there’s little doubt that KTM has made some detailed improvements to the RC16. The bike turns a bit better, which has the knock-on benefit of reducing rear-tyre wear – the RC16’s biggest problem – because the rider doesn’t need to use so much rear tyre to get the bike turned.
Also, Acosta says he feels more comfortable when he’s at the limit, so he’s getting more feedback from the bike, so he can push harder with less risk of falling, which gives a vital performance boost.
And yet his race time – finishing 5.5 seconds behind winner Marco Bezzecchi was actually 1.7 seconds slower than Brad Binder‘s 2023 race time, when Binder finished third, a fraction of a second behind Jorge Martin and Bagnaia.
If the factory KTM team had a great weekend, Tech3 had a disaster, with Enea Bastianini 12th and Maverick Vinales 16th.
The front of Vinales’s stripped bike shows an electronics hub above the air intake, which gathers together sensors from a multitude of data sensors. MotoGP bikes feature more than 500 data channels from engine and chassis sensors.
But it wasn’t all bad. The M1 may be slow but it’s got the neatest side aero on the grid, with its lateral surfaces, diffusers and so on all contained within a single flowing design; a bit neater than Aprilia’s RS-GP and much neater than Ducati’s Desmosedici, Honda’s RC213V and KTM’s RC16.
The Thai MotoGP season-opener was full of surprises, but was Buriram a blueprint for 2026 or a mirage?
By
Mat Oxley
Aerodynamics were crucial to Yamaha’s decision to switch from an inline-four to a V4, because a V4 is narrower (two cylinders wide, instead of four), which leaves more room for aero appendages.
Also note the vortex generators (red arrows).
Quartararo’s race pace was 1.2 seconds slower than the winner’s and the 2021 MotoGP king attributed much of that to lack of horsepower, which is the new M1’s biggest problem. Quartararo doesn’t expect an engine upgrade until May’s French GP, which suggests that it will be a significant redesign, rather than a minor tweak.
“We’re losing about a second a lap – so we’ve got to suck it up and get on with it,” said Pramac Yamaha’s Jack Miller, who ended last year 17th overall on the inline-four M1. “With the V4 it’s easier to change direction – the bike is twitchier. And you can centre yourself to try and use the rear tyre to stop the bike more, taking some of the load from your arms to your legs.
“The way the bike turns isn’t bad and the feedback I get from the front tyre is quite nice. I could feel the limit, especially when we went over 2.1 [bar, pressure]. I get good feedback, so you’re not wondering what’s going on.”
