Will Honda race its Kalex MotoGP chassis at Le Mans?


Honda tried its new German-built chassis during last week’s MotoGP Jerez tests, so the next step is to race it, possibly this weekend. But what engineering secrets is Moto2 dominator Kalex using to make the RC213V faster?

Bradl testing the Kalex RC213V chassis for the first time at Jerez

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Honda’s MotoGP project has been in a hole for a while. Without the superhuman talent of Marc Márquez – with whom the company won 12 riders’ and constructors’ titles in seven seasons – Honda has struggled to get close to the front of the pack, let alone the podium.

Álex Rins’ victory at COTA last month gave hard-pressed HRC and Honda bosses a rare glimmer of light in this long tunnel through which they’re travelling. Jerez last week was back to reality with bang: Takaaki Nakagami was the top Honda on Sunday, in ninth place, while new Repsol recruit Joan Mir hit the ground twice on Friday, in both the sprint and GP races and once more in Monday testing.

Many people suggest that Honda is in this hole because it has followed Márquez’s development lead. But this is nothing new: the company’s policy has always been to build a motorcycle that will do the ultimate lap time and then hire a superhero that will make it do that lap time: Mike Hailwood, Freddie Spencer, Wayne Gardner, Eddie Lawson, Mick Doohan, Valentino Rossi, Dani Pedrosa, Casey Stoner and Márquez, for example.

Sometimes Honda engineers got it right, sometimes they didn’t.

The RC181 that Hailwood rode in the 1960s was a pig, a fast pig. The NS500 triple with which Spencer won Honda’s first premier-class title in 1983 was a sublime, game-changing motorcycle. The early NSR500s that replaced the triple were nasty, evil things, which Spencer, Gardner and Lawson somehow wrestled to championship success.

Then Lawson, his engineer Erv Kanemoto, Doohan and his crew chief Jeremy Burgess helped HRC transform the NSR into a superb race bike, which everyone wanted.

The divine RC211V, which dominated MotoGP’s 990cc era, was the same. Then things got tricky again. The 800cc RC212V that replaced the 211 took four years to get right. “It wouldn’t even go in a straight line,” Pedrosa told me once. Finally HRC got the bike sorted, signed Stoner and was back on top again.

Kalex RC213V at Jerez 2023

The Kalex RC213V is wheeled out at Jerez last week. This bike has a new aero package, with larger diffusers in the fairing lower

Mat Oxley

The RC213V is related to the 212. It’s a razor blade of a motorcycle, which takes big balls to tame. Márquez’s huge successes on the bike simply turned that problem into a non-problem.

Honda won 69 MotoGP races in Márquez’s first seven years in MotoGP (Marquez, 56; Pedrosa, 9; Cal Crutchlow, 3; Jack Miller, 1) and has won four in the three seasons since, all but one with a barely fit Márquez on board.

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Incidentally, HRC did try adapting the RC213V to create more corner speed for Pedrosa, but whatever improvements engineers made in this direction they found the changes destroyed the bike’s best points and reduced overall performance.

Last year HRC got Kalex to make a swingarm for the RC213V, which Márquez used at the last few races, and now the German company has created an entire chassis for the bike.

Either this is a sign of HRC desperation or a more open mindset. If it’s the latter then it’s a good sign, not a bad sign. Look at KTM. The Austrian company has gone from zero to hero since hiring its latest group of staff from Ducati. MotoGP has never been more hotly contested, so you must get knowhow wherever you can get it from.

And anyway, the Kalex RC213V isn’t a first. In 1968 Hailwood equipped his RC181 with a British Reynolds chassis, in 1980 Honda commissioned an NR500 chassis from British company Maxton and in 1988 HRC allowed Burgess to modify an NSR500 chassis at HRC’s European base.

Márquez probably best summed up the RC213V’s current issues at the end of last season. “I don’t have front feel, the bike doesn’t turn, then no grip, so no acceleration,” he said.

Test-rider Stefan Bradl, who won Kalex’s first Moto2 title in 2011, added, “The front turns but the rear doesn’t want to turn, so the whole bike doesn’t work together. We always have to fight to get what we want – braking, turning and so on. And because things aren’t smooth and working together it’s easy to make mistakes”. Hence all the crashes.

Aero MotoGP

Alex Baumgartel designing a Kalex chassis on the Siemens NX CAD program, used throughout the automotive and aerospace industries, to measure chassis stresses in all scenarios

Jörg Künstle

Kalex was the obvious place for HRC to go. The tiny German company – which employs less than ten staff – has dominated Moto2 for more than a decade and if Kalex wins Sunday’s French Moto2 race it will become the second most successful intermediate-class constructor, after Honda.

During this period it has won more than 160 Moto2 races with around 40 different riders, including current MotoGP men Pecco Bagnaia, Enea Bastianini, Marco Bezzecchi, Bradl, Fabio Di Giannantonio, Pol Espargaró, Augusto Fernandez, Raul Fernandez, Jonas Folger, Luca Marini, Alex Márquez, Jorge Martin, Franky Morbidelli, Nakagami, Álex Rins, Maverick Viñales and Johann Zarco.

That doesn’t happen through luck or chance. Kalex knows what it’s doing and has created chassis that all kinds of riders can ride to victory, because chief designer Alex Baumgartel isn’t only a brilliant engineer, he also understands the human side of motorcycle racing.

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“Car racing is the complete opposite – it’s all data, more or less,” says Baumgartel, who previously worked in car racing, designing drivetrains and suspension for Opel DTM cars. “I enjoy bikes more because this ‘black hole’ that the rider calls feeling is super-interesting.

“You read the rider’s eyes to know if the bike is working or not; the look he gives you is more important than what you get from the datalogger. And we have to remember that when a car racer gets into trouble he goes into the gravel and the mechanics clean the car, but when a bike racer gets into trouble he feels pain.”

Everyone knows that a certain amount of flex is important in a racing motorcycle chassis, because at high lean angles the suspension becomes very inefficient, so the chassis must laterally flex, so the bike flows over bumps and imperfections in the asphalt, which aids grip, which the bike need to turn.

Baumgartel takes the flex concept a step further and we have to assume he’s used this in his RC213V chassis.

MotoGP Kalex frame beams

A batch of CNC’d right-side outside Kalex frame beams, almost ready for full assembly. No parts are bent or heated (beyond minimum welding) because this destroys consistency

Jörg Künstle

“Flex is a tool of steering,” he explains. “How the chassis bends under certain loads gives a self-steering effect, which makes the bike turn more easily. Imagine the frame and swingarm curving like a banana. With the centre of gravity more or less in the centre the chassis makes a curving line through the corner. This helps turning because something curved will turn a corner better than something straight, which forces all the turning through the front tyre, which can overstress the tyre.”

And we all know that the RC213V front end needs fixing, because it doesn’t give riders much feeling.

Of course, it’s not as simple as making the bike bend its way around the corner.

“All race bikes are softer than road bikes in the lateral plain, to achieve flex at high lean angles,” Baumgaertel continues. “But they also need to be stiff enough to allow fast changes of direction and to avoid wobbles that can reduce tyre contact. The task is to separate lateral stiffness from longitudinal stiffness, with the frame, swingarm and forks.

“We play with the way we shape the frame and swingarm, tailoring wall thickness from 1mm to 5mm. You have to make the frame without any weak points in the stress areas.”

Obviously, the Kalex RC213V chassis looks more like an RC213V chassis than a Kalex Moto2 chassis, because it needs to fit around an RC213V engine, not a Triumph 765 engine. And a MotoGP bike can reach 225mp (363km/h) against a Moto2 bike’s 185mph (298km/h) and achieve 2g of deceleration thanks to its carbon brakes.

“MotoGP bikes need more trail and wheelbase because of their higher speeds and their braking performance,” Baumgaertel explains. “When you’re leaning into a corner with nine bar of brake pressure and the rear wheel in the air, you need a bit more trail! Also, their corner speed is little a bit less than in Moto2 because the bikes weigh more and use slightly wider tyres.

Kalex Moto2 chassis

A Kalex Moto2 chassis on the bench at the Kalex workshop in Bobingen, southern Germany

Jörg Künstle

“Wheelbase gives you tyre grip and control – a shorter bike should have more grip, but when it loses grip it will do so more aggressively, while a longer bike will be more controllable.”

A MotoGP chassis has many jobs, but let’s super-simplify things by dividing its duties into three phases: corner entry, mid-corner and corner exit.

“You can make a big difference to the rider’s rear-tyre contact feeling during the entry phase by adjusting lateral and torsional stiffness in the swingarm. If you’ve got a super-stiff swingarm the rear will get very snappy when it steps out, because there’s no damping in the side forces.

“The mid-corner phase, when the rider is about to release the front brake and hasn’t yet touched the throttle, is the key point. It’s only a few metres of track but this is the moment when most of the turning is done. If this phase is precise and well controlled, the rider can prepare a good exit. The aim is always to reduce the time between releasing the front brake and the first touch of the gas.

“Then if everything is right the rider uses constant throttle for a few metres to start the rear tyre spinning, which takes him into the next phase: pick up the bike and use full throttle. We need to make compromises with chassis stiffness to make this phase sweet, controllable and easy to handle. But getting the drive spin right when the rear is stepping out isn’t easy because it’s a non-steady state of loadings.”

These are considerations that Baumgartel has put into his RC213V chassis, which is different in all kinds of ways that we can’t even see from the outside. The geometry is similar, the swingarm pivot is very different, but most importantly we know nothing about alloy thicknesses, twist points and the other crucial details.

Kalex staff with MotoGP chasis

More than half of Kalex’s staff! From left, owners Klaus Hirsekorn and Alex Baumgartel, then Michael Ferger, Lucas Bertele and Matthias Kanth

Jörg Künstle

The big question now is will Márquez – assuming he’s fit to ride – and Mir try the chassis at Le Mans this weekend, or at upcoming races? The Kalex RC213V made its debut at last week’s post-Jerez tests and feedback was good, so why not give it a go? After all, Honda has little to lose at the moment.

However, there is a problem. Riders now get three practice sessions on Friday and Saturday, instead of four, due to the sprint. And riders only get Friday’s two sessions to determine their place in Q1 or Q2, which can make or break your weekend. For example, Fabio Quartararo probably destroyed his entire Spanish GP by failing to do a time attack in P1, so how can anyone test a whole new chassis on Friday, which might put them 15th or worse on the grid?

Perhaps Honda could evaluate the Kalex in Saturday morning’s 30-minute free session, which doesn’t count towards Q1/Q2, but that’s not a lot of time and then they have just ten minutes before qualifying, so it’s all a big risk.

This highlights the problems of MotoGP’s new format, because it substantially reduces a team’s ability to make improvements to its motorcycles. Thus it preserves the status quo: when there’s less and less testing and less and less practice it becomes more and more difficult for a manufacturer to dig itself out of a hole.

Is this good for MotoGP? I don’t think so. Because how long will struggling factories like Honda and Yamaha stick around when the odds are more than ever before stacked against them when they’re trying to dig themselves out of their respective holes?