Everyone knows Honda’s RC213V is no armchair ride. But why? Best man to ask is Takeo Yokoyama, HRC’s technical manager who works with Marc Márquez, Cal Crutchlow and now Alex Márquez
What engineering concepts went into building the 2019 RC213V which dominated last season in the hands of Marc Márquez but sometimes made life difficult for Cal Crutchlow and Jorge Lorenzo? And what kind of a bike is Honda building for the 2020 MotoGP championship?
Takeo Yokoyama can answer these questions like no one else. The HRC engineer joined Honda in 1996, starting out in the production chassis department, designing chassis for the CBR600 and other road bikes.
In 2004 he moved to HRC, where he worked on chassis design for the RS250 GP bike and MotoGP machines. He became HRC’s technical director in 2013 and technical manager in 2018.
Your biggest improvement last season was horsepower. Where did all that extra power come from – the intake redesign that we know about or from inside the engine?
It was a little bit of everything: the intake, changing the throttle bodies and a lot, a lot of changes inside the engine.
If you look at our 2018 cylinder head and compare it with this year’s cylinder head the difference isn’t massive. But there are hundreds of other small details. If you look at our parts list you’d be surprised – almost no parts were carried over from the 2018 engine.
Honda has always been big on reducing internal friction, so was that as big as the combustion changes?
It’s always both. Every year we try to reduce friction and we also try to get as much from the combustion as possible. Of course it’s always difficult to gain more power everywhere, so if your target is to gain more on top, then you have to sacrifice power somewhere else.
It seems like you made a big decision for 2019: let’s make Marc’s life easier, by giving him more speed so he has to take fewer risks…
How we discussed it was like this: if you split the whole track into different areas, starting from upright braking, then going into the corner, edge grip, traction area, upright acceleration; in all of these areas tyre grip is the limit.
Of course, in upright braking the limit is also the rear lifting, but once the rider is in the corner the tyres – front and rear – are the limit.
In these areas the rider does his maximum. He is trying to manage the situation by moving his body and by changing his operation of the front brake, the rear brake and the throttle. But when the rider is upright accelerating and once the wheelies stop, after this even the best rider in the world can do nothing.
So this is where we had to work – on the speed in fourth, fifth and sixth gears – once tyre grip is not the limit anymore and once the traction control and wheelie control aren’t the limit anymore.
This is the area where we have to help as much as possible, because in the other areas we know we have Marc, who can manage different situations in the best way.
The Michelins are very delicate when it comes to bike set-up, so how much do you work on matching torque delivery to tyre character?
Like you say, the Michelins are a bit more delicate. As long as you handle them in a good way the potential of the tyres is so high, they are so good in terms of lap times and consistency. But once you are out of the range of how to control the tyres then it’s a disaster.
So like everyone else we work very hard to study the character of the tyres. From the control side, especially from the electronics, we try to get the best optimisation to get the maximum from the tyres.
Also the riders – and Marc is especially good at understanding this – need to understand which throttle opening to combine with which lean angle and how much load they need to put into the tyres to get the maximum potential from them. So it’s a combination of job from the riders and the engineers.
The 2018 and 2019 RC213V bikes looked a bit different because you ducted air through the steering head, not around the frame, but their overall layout looked similar. So how do you explain the fact that riders said the 2019 bike was more aggressive to ride and Marc had to lean further to make it turn?
Our main focus for 2019 was to get more horsepower, especially top-end horsepower, which means we didn’t change chassis geometry so much. Centre of gravity, weight distribution and all these features were very similar between the 2018 and 2019 bikes. So basically the bike didn’t change so much, but it’s true, from rider feedback it seems like the chassis character did change. Of course, part of the reason is stiffness around the front end, but I don’t think this is the only answer.
Presumably your engineers tried to replicate the stiffness of the 2018 chassis?
That was the starting point in the wintertime. Then, depending on rider feedback, we continued to change stiffness around the front, the rear and the middle of the chassis, because that’s what we always do: adapt the bike according to rider feedback. So if you compared the stiffness of our latest 2019 chassis to the 2018 chassis it’s not the same, it’s quite different.
How many frames did you use during 2019?
I don’t remember exactly, but something between seven and ten. Sometimes we bring a frame to a test and after one or two runs it can be discarded.
How many did Marc actually race, because presumably he likes to keep his chassis the same for as long as possible?
Yes, especially when riders feel not so bad on the bike they don’t want to lose that feeling. Marc maybe used four different chassis during the season.
Does Cal use the same chassis?
Cal uses something a little different and only raced one or two different chassis. But Cal tried even more options than Marc, because often we bring something new to a track and we ask Cal to try it first, especially when it’s more experimental.
Presumably the change in chassis feel you mentioned came from the increase in horsepower and torque?
Yes, a lot, a lot, because it’s not only the amount of torque, it’s how the engine generates the torque and the behaviour of the torque. If the reaction from the engine is different, then the requirement from the chassis is also different.
Cal talked a lot about his issues going into corners, was that related to negative torque?
Yes. In the end, the engine-braking side and the acceleration side are the same, because now everything is controlled by torque, so when we speak about torque the only difference between acceleration and deceleration is it’s plus or minus. How we control both is very similar. So if we have some difficulty on the acceleration side, say throttle connection, then we will also have difficulty with the negative-torque side, which is engine-braking.
Marc managed it well, until he slid off at Austin, and then you worked to fix the problem, but presumably it stayed an issue all year?
If you also ask our riders what they think about throttle connection, maybe they’ll say they’re not as happy as they could be. So it’s both sides – acceleration and braking.
If the engine has more torque, for sure the rider’s job is harder. He may get more corner-exit speed but he will have to work harder with throttle control, body position and fighting the bike.
Do you think we are in an era in which the bikes are harder to master because the spec electronics don’t smooth everything out?
For the Honda I think, almost yes, because every year we increase power and torque, so it becomes more difficult to manage the bike’s behaviour. But also, the Honda has never been that easy to ride.
If you look at the Yamaha it’s always been a smooth, flowing bike. But even with factory software and Bridgestone tyres the Honda was always dancing!
Ducati’s Davide Tardozzi and KTM’s Pit Beirer say an easy bike is no longer good enough to win the championship, they say the rider must fight with the bike.
I’m not convinced that the rider must always fight with the bike, or that a smooth bike cannot win the title. What I can say is that it is not in Honda’s DNA to make a smooth MotoGP bike.
So Honda’s job is to win races, not to make life easy for the rider?
Exactly. We’ve spoken with Cal many times, especially when he came to Honda from other manufacturers, and he requested an easy bike. My argument was, okay Cal, we can try to make an easier bike, but I’m not sure it will make you faster.
In the end I said to him that with a Honda MotoGP bike you have to fight and that’s why we pay you!
Marc crashed much less in 2019 – from 27 crashes in 2017 and 23 in 2018 to 14. In 2019 What are the reasons for this?
There are several reasons. First of all he doesn’t need to squash the bike on the brakes and go into the corners like an animal, because he has more horsepower. The bike is faster in fourth, fifth and sixth gears, which makes his job easier going into corners. Also, he can think more about how to save front-tyre life and how to keep good grip to the end of races.
That’s two reasons, but also Marc improves as a rider, year by year. He feels the bike and the tyres a lot, he understands everything that’s happening, so when he’s in an on-the-limit situation he can make his saves a lot more.
He had 14 crashes last season, but if you count all the saves he made, maybe it’s more like 30!
But if it’s not a crash it’s not a crash! You also worked on the front end to give more feedback, is this why he saves more crashes?
Marc gets good feedback from this year’s bike, or at least good warning. For normal riders we need to give them a nice-turning bike, but all Marc needs is some feedback from the tyres and he manages the rest. As long as he gets some warning from the tyres he will make the bike turn.
Was the idea of looking after Marc’s injured left shoulder a factor in your development for the 2019 bike?
Of course, the situation for every rider is easier if he doesn’t crash too much. When the surgeons opened Marc’s shoulder and Alberto [Puig, Repsol Honda team manager] told us how bad it was we were worried and we were more determined than ever that we must take care of the riders.
But honestly speaking this worry didn’t affect bike development so much – we already had the idea to increase horsepower before this.
What are your development priorities for 2020?
On the engine side we won’t stop working on improving combustion and friction; we will keep going like always. At the same time we want to make the bike… I wouldn’t say easier… but this year we faced many problems and we realised that we sacrificed so many things because our main target was top-end power.
We realised the sacrifices we made compared to the 2018 engine, so these are the points we want to fix for next year, without losing any power, of course.
You’ve talked about the increases in torque and negative torque, so you’ll presumably change the chassis balance to compensate?
Yes. We have to change the chassis side: geometry, weight distribution and so on.
Márquez is different, so do you see HRC building one chassis for him and others for everyone else?
With engine development we have to go in one direction because of the regulations. On the chassis side we are open and we have no problem with going different ways, rider by rider, if it’s necessary.
But during 2019 we tried many different chassis – softer and harder at the front, rear or middle – and frankly speaking I didn’t see our three riders [Márquez, Crutchlow and Jorge Lorenzo] take many different directions. There were slight differences, but nothing dramatically different.
Márquez raced with a carbon-coated frame in Austria, is this is a development direction you’ll continue?
It’s one of the tools we can play with. The good thing about carbon fibre is that we don’t need to make a completely new chassis, we don’t need to start from billet machining, which takes a long time.
With carbon we can add one ply here, two plies there, so when we see that something isn’t correct in the stiffness at the front, middle or back of the chassis we can react more quickly.
Can you remove the carbon fibre?
Yes, sometimes we do.
Suzuki uses an aluminium/carbon-fibre composite frame all the time. Might you do the same or is it just an experimental tool?
It depends. We will keep changing chassis stiffness and trying things forever. And if one day a carbon-fibre coated chassis works really well then of course we’ll continue with it.
Is the carbon coating only about stiffness or is it about changing the flex and reflex character of the aluminium frame?
You can say either reflex or damping. When you use different materials and especially when you mix them together then the character of the transfer changes.
Some people say the reflex character of carbon fibre isn’t correct for a motorcycle…
Sure, it’s different. But you never really know what’s correct and what’s not correct, which is why we cannot stop working.
Source: motorsportmagazine.com