The Conversation That Changed How I Understand Skis: Jurij Franko on the Birth of Modern Ski Design

Okay, well, thanks for joining me today, Yuri, on the Global Skiing Podcast. I must say, I noticed some posts from you on the Facebook forum Elite Skiing probably a few years back, just noting that the kind of comments you made intrigued me and made me think this guy knows something about skiing and more than the average person. Knows about skiing. And lo and behold, a little bit more research, I find out that you were actually around— I guess, if— tell me if this is correct— in the, the early developmental stages of shaped skis. Is that right?

Yeah, actually. So the story is a bit more complicated, but okay, let me put it this way. I was original author of mathematics to prove that Chapskys are okay.

Really? So it was almost— it was— so you were— it was kind of your hypothesis to prove that?

Yeah, yeah. So I have explained that also in this webpage Seth Messiah is setting up. Uh, so it was A long time ago, when I started in ski business as professional. Before that, I was just skiing as a racer or afterwards as a ski patrol and that kind of stuff. But in '80s, late '80s, I got a job in Elan. I always wanted to work on sailplanes or on aeroplanes because flying is my main hobby.

Yeah, okay.

I couldn't get a job there in this department of Elan, so I got a job in ski department. So it was one step closer to my goal.

Yes, yes. So, so I, I just thought I'd start out with that introduction because I wanted to hook people into why they— why I think they should probably listen to what you've got to say today. But if you rewind back and maybe set the scene with a little bit about your, I guess, your upbringing or your, your skiing background. You said you used to ski race, so maybe if you want to just tell us a little bit about that. So, which possibly, I guess, fueled a little bit of interest and, I guess, understanding of, of how skiing works before you kind of, I guess, applied the physics and engineering side.

Yeah, okay. I was skiing as a kid till I was 15. Nothing special in racing because I was in competition with guys like Boris Strel, who was my classmate, and he was actually the first winner of world championship medal for Slovenia, or Yugoslavia at that time. So I was far behind. Better than us.

You had some competition.

Yeah, yeah. Or for example, Bojan Križaj was also, let's say, competing at the same time when we were kids. We were together. So I knew that there are guys who can ski much better than I did.

Yeah.

But of course, racing is one thing and the other thing is also understanding what is going on.

Yes.

So, and I didn't pay attention at that time about skiing. As all kids, I just took it for granted what the coach said that was true, and that's it. Yeah. And later on, studies, physics, I was, I say, always involved in science or studying physics, not very good at it, I must admit I had problems with mathematics. But I finished my studies okay, and then I went into business. After a few years, I ended up in Elan as head of laboratory. So that means I was in charge for measuring all skis, all the equipment they were producing in Elan. Mm-hmm.

And back then, can I ask, because I guess I came to skiing a bit probably later, definitely later than you. So back then, was Elan possibly— was it one of the major ski manufacturing— I mean, I don't know if it still is one of the major ones. Can you fill us in on a little bit about where Elan was in terms of, I guess, its competitiveness or like research development side of things in the whole ski industry?

In late '80s, Elan had Stenmark, so— Ah, right. We had everything.

Yeah, okay.

So we were, let's say, quite high in this industry. On one side, on the other side, of course, business is something else. It's not— all about racing.

Yes.

So Elan as a company was not very successful as a company, as organization, and there started my other business also later on in my career. So at that time, let's say, we were working together with Andrei Robic. Andrei Robic was, he's now in I believe he's 85 now. I still have contact with him. He was author of all skis for Stenmark.

Wow.

Yeah, okay, and he is, let's say, he supported us youngsters in developing new ideas. He's still very open-minded. He's— and he had a certain reputation because of his achievements. So we had quite the support.

Okay.

At times we could be involved in new ideas, in crazy things.

So how did, how did this start? Like, was it, did— was it someone like Stenmark? Was it, was it you who suggested you thought skis could could be made differently. I mean, is it worth maybe starting out with how a ski actually works? What the mech— like, what, what order would you say would be better to talk about so we get a better understanding before the evolution of, I guess, carved skis coming along?

The key point was when I came as a physicist in Elan, I started asking questions. What's the theory behind it? And what is going on and so on. And Andrey, as the key figure in Elan at that time, he simply said, I don't have a clue. So that's where it all started.

Got it.

I read all the literature, everything about skiing, and nothing really made sense. Huh. You know, somewhere in the path, I found it contradicts Newton's laws or some common sense. Yeah, yeah. So I said, this is something wrong. And later on I discovered it's a simple rule everywhere in every industry: if the army or military was involved in history in that industry, then everything is known, so the theory behind is done.

I got it.

If it was not involved they, they don't have a clue. Okay, building on the experience.

Got it.

So, and that's the situation with ski industry at that time. And the question was, why, how can we make a ski which will not skid? So skidding is braking, so slowing the skier down and so on. And So we made, uh, so at that time they made different experiments, for example, skis with, uh, double, uh, edges. So on every side you had one steel edge and another one on top of that.

Wow.

You have double grip.

Wow.

Of course, this was not working. Okay, and then, uh, I have 3 kids. So at that time, my boy, my middle kid, was 2 years old. We were on holidays. He was not sleeping. He was crying in the night. I don't know why, but I was half asleep, and then I got an idea. Uh, the problem The idea is, what is skidding, in fact? Or another way around, what is not skidding? So, it's a little bit complicated, but if you imagine a point on the ski slope—

Yeah.

Not skidding is that every point on the ski edge goes through the same point on the ski slope. Yep. That's pure definition. So, if you make a radius of 10 meters, so every point on the skin must lie on that radius. And that's, the result is then geometry. Yes. Put some mathematics into it and you get a sidecut. Yes. It's, so it took me about 30 minutes to make all the math work. Uh-huh, uh-huh. And that was it.

And then onto, into the, into the labs and start?

No, just, just so persuading Andrei first to support me to make a prototype. And then we just went out to the ski slope and it was working.

So, you know, because I, I don't know if this is a myth or something, but Had snowboarders already put sidecut into snowboards, and were they carving already?

Yes, they did. Yeah, I was just explaining my way of thinking at that time.

Got it.

Yes, yes.

It was not, let's say, oh look, they have sidecuts, let's make it on the skis. Yeah, it's not like that.

You'd come across that you had the, the, it's like, how can we make a ski that does not skid.

This is—

it must go through all points of the ski, must go through a point, and then you were okay. So you went from that angle.

Yeah, because as physicist, I must have a, let's say, background in mathematics. So you calculate everything, you not just assume something that happens. Everything must be calculated. Yes, that's a professional deformation.

Yes, yes. Got it. And so then what was the first prototype like? Was it like, what radius did you— was the first prototype?

So first prototype, so actually I have a second prototype here behind my back. Now, first prototype was, uh, 193 centimeters long. Sidecut was about —what was that?—14 meters sidecut radius, because in mathematics actually sidecut is not radius, it's top of the sinus curve. Okay. That's why I don't like to talk about sidecut radius, but it is close enough.

So what— okay, so then what do you, what would you, what is a more accurate way, or is it not accuracy, is it just a better explanation?

Uh, no, it's in mathematics. Okay, for, for every single radius of skiing and for every angulation, you have different shape of sidecut. That's in theory. Yeah, in practice you cannot produce skis inside those tolerances. So, okay, it's, it's just, uh, let's say mathematical trick, not, uh, Reality, in reality, it's good enough to have a radius.

Okay, got it, got it, got it, got it. And so do you think there are any more things worth noting about like how a ski works? Like as in, like what are the elements that need to be present for a ski to turn, whether it's skidded or carved? Either one? Like, are there— what is— what are some of the, you know, physics principles, I guess, that people need to, to understand, have to be present for a ski to turn?

Okay, let me go back into the history again, because after we discovered that carving or sidecut works, we still didn't have a clue what is the physics behind skidding turn. The question is why some skis perform this way and the other ones that way. Some are, let's say, good, some are bad. Where is the key connection between physical properties of the ski sidecut, torsional stiffness, and bending stiffness, and with performance of the ski? For example, the basic question is some skis don't work on hard surface. They simply don't— seems they don't hold. So in my professional deformation, I made measurements. I took— built a special device to pull the ski sideways on the snow and to compare results. So you have different skis with the same angulation angle and pull it sideways and measure What is the force? And would— was the snow—

what sort of snow surface?

It was different snow surfaces. It doesn't matter, actually. Okay. So you just pull and measure and compare. Because feelings tell you that some skis don't hold and some skis hold. And then you measure. And when you measure, there is absolutely no difference. In friction force sideways. Uh-huh. This is the key idea behind it.

So, okay, so let me just re— let me just repeat that again. So a person can feel the difference between different skis skidding sideways, but yet if you use a mechanical machine to measure that side, like skidding, it comes up doesn't matter really what you do with the ski, the same measurement is read. Is that right? If the same angle is against the snow? Yes, exactly. Aha, very interesting.

Doesn't— so we were comparing kids' skis, short skis for children, racing skis for World Cup racers and so on, and all in between. Yeah. And the results were consistently the same.

That would go against what most people would think. Would you agree?

Yes. Yes. And of course it was against what we were expecting.

Cool. Keep going. I like this. It's good.

Okay. So the question is, then what is the difference?

Yeah. It's got to be what? It's got to be the skier then. It's got to be the person riding it, or has it just got to be weight on the ski?

No, no, because if you go on the slope and ski with skis, different skis, you feel consistently the same difference with different skiers. They all agree that this ski is holding better, this ski is holding— is not holding as good in holding, and so on. Yeah, yeah, you get those consistent results. On the other side. So the question is, where is the difference? Yeah. So yes, and in physics we know we differentiate two types of movements of skier. That's translation and rotation. Okay, in translation, so you're going downhill or making curves, you are following a certain path. This depends on the external forces. And external forces are, as we defined, measured always the same. So there probably is not a big difference. But rotation is another question. So it turns out that the skis which don't hold on icy slope, they are not stable enough in directional sense. So that means if you put your center of gravity just a little bit off, the ski will rotate out of the turn and you will have a feeling that it's not holding.

Aha, okay, okay, yes. So the ski wants to— so that's when people talk about like a— the ski having a self-steering effect. It kind of break, the tail breaks away and the ski turns on itself. Yes. Yes. And that's dependent on the alignment of the center of gravity through a particular point on the ski, is that right?

Yes. And of course, when your center of gravity goes off a little bit, that will produce torsional deformation. Of the ski. So that's when the torsional stiffness comes into play, because in this measurement, when we measured torsional stiffness, did not have any influence on how the ski is holding. But when you go off just a little bit in front or behind the binding area, yeah, then you can get huge differences.

Huh. And we are just purely talking, like, say, in the fore and aft, going off the direction, off this line, this center point. Is that right? Yes. Yes. Not, we're not talking in like the lateral frontal type plane. So, or is that a next thing?

The key point is where your complete force is acting on the ski. Okay. It changes over the course of a turn. Yep. It's very complicated, but intuitionally, so good, good skier has this muscular memory and he can adopt this position very precisely, and he can ski effortlessly because he is fast enough in adopting correct position regarding on the phase of the turn he is currently in.

Got it. So he's constantly— he is so in tune. Every time, if maybe he doesn't line up as well, he will adjust his center of gravity to line up better so that ski holds again. So yes, kind of. So it's constantly throughout different points of the arc, he knows how to line that up and, and, and the feeling that he gets from that. Exactly. Or she— I should say he or she.

Or she, yeah, okay, let's be correct. Yes. Okay, here snowboarding comes into play. Mm-hmm. Okay, so I started snowboarding and I learned you must go forward, backward, and forward and backward on snowboard. That is very easy to determine if you are putting more pressure on front or back leg. Yes. It's very easy. On skis, this is not that simple. No. So, but snowboarding is the same physics.

Yeah.

So I learned from snowboard back to skiing that this is it. And then we made some complicated devices how to simulate that into lab and so on, but it proves that, uh, so snowboard had influence on the ski theory development.

Yeah, cool. So would you say then, like, because I guess a snowboard is— because the feet are wide apart, more spread along the whole entire length of the piece of equipment, have you got a much larger room for error? Would that be correct? Or not necessarily. No, no. Or do you— if— or does the person just sense it more easily? Be like, what— how would you describe that?

Yes, more or less. You— it's more easy to feel what you have done and what is the reaction on that.

Perfect. Okay. Yep. So it's, it's actually a human sensory type of— that is, is the biggest difference. So, okay, so then could you almost assume the best skiers then have the most finely adjusted sensory awareness in their body?

Look, skiing is then more or less like, let's say, in gymnastics. In gymnastics, uh, if you make 10,000, approximately 10,000 good repetitions of the same element, then you learn that element. Yes. So it's all about proper repetition. So first to define what is the proper way, then to repeat that 10,000 times.

That's about it. Okay. So you, you, you do A, you get B, and you do it thousands of times. So then your body automatically knows when, when A happens, B, B will be the result. Yes, yes. Cool. Okay, sorry, I sidetracked you there. Where, where are we up? So you used— learnt from snowboarding to help and then test this?

Yes, yes. And, and then you learn that every device on snow, or for example, even the car They have, so device has a certain response to input. So, in your car, if you turn steering wheel for 10 degrees, you expect for every car to have approximately the same radius of a turn. Mm-hmm. It's the same for skis and for snowboards and for everything, but you don't steer with your your steering wheel, but with your position of center of gravity. So the property of every ski can be described of how fast the ski will rotate when you move your center of gravity for certain amount forward or backward.

Okay, yeah, sure. Yeah, yeah, okay.

A curve which at one point is zero. So at that point you can make a side movement without rotation. And then if you move 10 centimeters forward, you will rotate at certain speed or at a certain rate. Yeah. One or the other direction. Okay. So if you have a racing ski, for 10 centimeters movement you will rotate very slowly. —because it is made for higher loads. So at low speed, it is very difficult to ski with racing ski. And for beginners, because, you know, they are slow, they don't make such big load on the ski, you make a ski which rotates much faster for the same amount of center of gravity movement.

Movement, okay. Yeah, right. Interesting. And so what are you doing with the ski then that makes that difference? Because I know what it feels like, because— but what exactly is it that you're doing to manipulate that? Uh, it's very simple.

Uh, core thickness. Only and only that. Really? Yes, because the bending stiffness and torsional stiffness— so bending stiffness goes up with power of 4 with, uh, core thickness. So if you change core thickness by 10%, yeah, bending stiffness will go up 40-50%. Okay, so in ski production then you have a big problem because you have the skis are relatively thin. Yeah, I can imagine the core thickness in the shovel or tail. Yeah, it's about 1 millimeter. Yeah, so every tenth of a millimeter will produce quite a change. Yeah, right.

And so does it also— the core, not only the thickness, so the core material makes no difference? More or less, no. Okay, it has a small effect?

Yes, it has a small effect. So if you change wood from, let's say, poplar to birch or something, it will make some effect, yes. But generally speaking, when we are talking about ski production, yeah, not about ski experiments and all that stuff, in ski production Your goal is to use as little input material as possible to make as much different skis as possible. Mm-hmm. So, and this can be done for the whole range of skis. This can be done with, uh, 4 constructions, generally speaking. So you have 2 core materials, 2 types of laminates or aluminum or whatever and combination of those and that's it. And you can produce any ski you like. Of course, you cannot sell this concept to the end customer, so you must, let's say, produce some marketing stuff on top of that. Okay.

So, I mean, then what— so when I ski like a cap constructed ski versus a sandwich constructed ski, what is— is, is a lot of it like the feeling difference? Has it got to do with the thickness, or like what is, what is it I'm feeling with the, with those differences?

So you are feeling differences in bending and stiffness, bending stiffness and torsional stiffness. Because the steel edge which is interacting with the snow, yes, the steel edge does not know what kind of core or construction you have on the top. Yeah. Even the, I say, the width of the ski, for example, is not important until you are, uh, you are outside edge is in the snow, because when the outside edge is in the air, what's the difference?

Yeah, yeah, no, nothing acting upon it.

Yeah, yeah, that kind of thinking you have to, let's say, keep in your brain all the time when somebody says you some crazy stuff.

Yeah, yeah. Okay, right. So, and then, so then in a— because I've just recently started skiing a lot more on like race skis that I guess would be like on the make, they're considered FIS style race skis. So it's not the, the high-end kind of like carve ski, but it's actually built for ski racing. And so in that ski, and I really like the feeling far more, like I felt like I was on toy skis perhaps all my life before then. What is like, is it also the type of wood that I'm feeling? Because I know that they're like, say, the Völkl Race Tiger and then the Völkl FIS Slalom Race Tiger, the difference is really amazing. But is it the wood in it that I'm feeling the difference with? Is it a number of factors? And, and is that— is that— that's just changing because I know it's stiffer. Yeah. Yeah.

Okay, so it's almost 20 years ago since I was last time in Fäkel in production, so I cannot answer on that how they are making skis now. But as far as I understand the industry big change. Yeah. So if we are talking about Völkl, they are using a very simple procedure for producing all skis. So maybe they have put some more, uh, glass fiber into the top skis than into the, let's say, less lower skis.

Got it.

But mainly, I would guess, is just the change in thickness of the core.

Yeah, now, now that I think about looking at them, like putting them— yeah, it probably is even a mil, 2 mil thicker.

Yeah, and then you calculate back, it's a power of 4. Yep, so then that—

yeah, right, so really, yeah, multiplies up. Doesn't it? And so even the binding plate then, that's why a ski racing ski will have a binding, a special binding plate.

So function of bonding plate, binding plate is twofold. First of all, it's a razor. So you are a little bit higher than normal. So my personal best in getting higher is 15 centimeters.

Oh my God, you didn't break your legs? No, no, no, of course not.

It's an illusion that this will break your legs. Uh-huh. It's another sad story about that. Okay, let's keep it simple now. So the plate itself It's torsionally stiff and it produces— or result of using a plate is also that the skin in the area of the plate is torsionally stiffer than without. Mm-hmm. But because the holes that hold the plates down are elongated, they don't interfere with bending stiffness. Okay. So you kept the bending stiffness or the line of the ski, but increased a little bit torsional stiffness.

Okay, right. And then the lift just gives you more leverage to tip it.

Yeah. The lift is just, let's say, side effect of the lift is that your ski boot gets on the slope later on at larger angulation angle. That's the only function of the Razor.

Yeah, okay. Yeah. So what happened when you had 15 centimeters? What was it like?

Oh, it was great. I was carving like crazy.

Yeah, I bet. Was it like almost like those, those snowboard, like body carving kind of people? Did you feel almost like that?

Oh, it was, it was very aggressive. I used, uh, for, um, slalom ski, racing slalom ski for, uh, for the base, and then I put some profile, aluminum profile, 15 centimeters high, and on top of that also ski binding, and it was really high. But the feeling, the feeling was so— it was a little bit difficult to skid, but on carving it was you are just like on a Formula 1 car, so you have additional edge grip.

Yeah, okay, so it just felt like it did not want to slide at all?

No, it did not. Yeah, it just carved down the slope as fast as you want. It was the same effect as with short skis, for example. Yeah, but we used to and produce also some kind of snow blades, and their sidecut was also about 7 meters or maybe less. And as long as you stayed on the edge, you could go, I don't know, 60, maybe 70 kilometers per hour. But on the edge. Yeah. The moment you were skidding, you were—

Just dangerous. Yeah, yeah, okay, yeah.

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Now, like, my head is going back to that skidding topic. So center of gravity moves forward or back from that— could you almost just call it the sweet spot? Yeah. So would— like, I'm thinking, right, on a snow blade or very short ski, wouldn't the room for error be smaller than a long ski, or is it got to do with another factor that actually— yeah, is that right? Yeah, that's right.

Because, you know, when you are talking about rotation, you're talking about torque. Yeah, torque is force multiplied by lever. Did I put it right in English? Yeah. So the longer the ski is, maybe the force on the tip or the tail is lower, but because the lever is larger, the torque is larger. Yes. Yeah. And that's the point of the long ski. Yeah. Okay. And when you measure back, if you go back to measurements, you measure pressure distribution under the ski. You can do that, and also many companies do that, and you calculate back torque from that. You have a completely different graph. For example, pressure distribution, or pressure under the tip and tail, is very small— could, could be very small. Yeah, but the torque on the center of gravity is, uh, the largest on the tip and the tail.

Yes, yes. Yeah, yeah. Okay, now in, in our messaging before we kind of lined this chat up, like, you're almost— you were saying there was a couple of myths you wanted to, to debunk. I mean, I think we've maybe started to get into that with how a ski turns, but did you want to talk on that topic, like the big toe? And yeah, that would be, I think, a good good thing to maybe bring up.

I, I always had a problem with, with this. I know I have a feeling, you know, this is my professional deformation. I don't have feelings. I have feelings for my wife and my kids and my dogs and so on, but I, I really don't feel— so my problem in ski testing, I was testing quite a lot in my time was that I didn't feel the difference. And then other testers said, okay, there is a difference, huge difference between that, that ski and that ski. I said, yeah, sure, it's some difference. I felt the same difference, but to me it was not important. Uh-huh. I could ski either way. So in my whole career I had maybe 2 or 3 pairs of skis which were impossible, which I said, okay, that's bad. Yeah. Otherwise, I could ski with every ski. No problem. Enjoy it. Maybe a little bit more, a little bit less, but not a big deal. So that's why this oversensitivity, or let's say making big thing out of nothing, This is what it, let's say, makes me nervous. And then of course all the stories about this tip of the ski is too soft and the ski will not work. I cannot understand that. I cannot understand relation between— because there is, when you calculate, no relation. Yes, you can make a soft— softer tip and softer tail and so on. But what will be the result on the ski slope? There's no linear connection with that. So you cannot prove it mathematically. If I make a softer tip, what will happen is if you make a softer tip, then the pressure on the tail will be reduced. Because of torque? Because sum of all torques on your body is on the ski is always zero.

Yeah.

So either the pressure on the tail is reduced or you will rotate. Okay. Because you don't rotate.

Okay, I see what you're saying.

Yeah, yeah, yeah, interesting. That's why in ski industry there's a lot of myths which don't have logical connection then to basic physics. Yeah. And, you know, like for example, we have changed this core and added stripes of this and this wood. Yeah. Into the core. Definitely this will not have an effect on the ski. The other big story is about vibration. Yeah. The tip is vibrating and that's why the ski is not good. Uh-huh. Okay. So, make a small experiment. Stand on skis and ask your friends to lift up and down your tip of the ski. Yeah. And then tell me if you are vibrating or not. Okay. You see the point? Yeah. Vibration comes underfoot. Yeah. Not because of tip and tail. Yeah. And so on. So there are, it is not enough energy to make all the system to start vibrating. Yeah. Just the tip or just the tail.

Yeah. Yeah. Okay.

The other one is, let's say, the basic one which still persists after so many years. I have loaded the ski and the ski bended. That's stupid. Think of it again. When you stand on the skis with your weight only, it's already bended. Okay? And then you ask your friends to piggyback on you, on your back. Will the ski bend more? Flat on the snow? Or sideways? On the slope? Yes. When you are on the slope, hard surface, hard snow, standing on the— standing still.

Oh, standing still and the ski is flat on the slope? No, it won't bend more because—

on the edge, because you are on the, on the slope.

Yeah. Oh yeah, yeah. Ah, yes. If you're standing still, no, no.

So why should bend more if you are in the turn? You are at the same edging. Yeah. And the same 2G load. Yeah. Okay, so if it doesn't bend when you are still, why should it bend when you are skiing? Okay. Obviously stupid. Yeah, okay. And think again, if it would bend, then the tip and the tail will stick into the air.

Yeah, okay. Yeah. Yep.

So what is holding tip and tail in the air? Yeah, nothing.

Well, so yeah, it can't. Okay, so then what is— so keep—

sorry, keep going. So it's that kind of let's say myths that are still after many years, uh, in ski— in skiing and repeating itself and repeating itself. And internet is just helping that.

Yes. So I guess it's, it's, it's not that the ski is not bending, it's just you're pointing out the mechanism of the bending. Is that correct?

Yes. Yes. Yes. The pressure distribution under the ski goes very smoothly. So you put the ski on the edge on the hard surface without load. There's only two points that contact, uh, contact points of the ski, tip and tail. Yeah, tip and tail. And pressure, you press it down and until you touch the snow surface with the center of the ski the ski will bend. Yes. From there on, it will not bend anymore. Yes. Because the pressure will be transferred from the underfoot straight to the snow surface. Yes. That's about it. Yeah. Yep. If the pressure would be higher in tip and tail, then the ski would bend, but—

Yeah.

No reason the pressure would—

But yeah, increase that. Yeah, okay. Yep. So, so then the explanation for it then is like a ski that bends more through a turn?

No. Or— no? Bending of the skis is defined by sidecut. Yep. Only by sidecut, nothing else.

Nothing, okay.

And the load needed to touch surface with the center of the ski is relatively low. Yeah. So everybody can do it. Yeah, true. He is not strong enough to bend the racing ski. Wrong.

Yeah, yeah, it's a wrong— yeah, yeah, yeah, it's true because yeah, you don't need that much, yeah, load, weight to put the center of the ski touching the snow. Yeah, okay, cool. That's good.

That's— and that's the basic one, and then you go on and on and on. I cannot even number all the myths, but this is—

so, so then I guess, because like, are you aware, like, sort of my thing is I'm very interested in I guess the body and biomechanics and what, how much someone can, I guess, use their body to affect what is happening with the ski. So then if we talk about lining up with this sweet spot along the length of the ski and not kind of, you know, making the tail break away, or I guess having the ability, because not all the time do we want the ski to be cutting in because we want to be able to slow down at points off-piste or avoiding people or make a sharper turn than the radius of the ski. So then, like, how much do you believe in, you know, talking about technique or movements made with the skier having an effect?

Yeah, okay, so different techniques, that means that, okay, let's put it again in the car situation. So when you're sitting in the car, you can turn the wheel left or right, but you can change your position in the seat and your ability to turn the steering wheel will be changed. Yes. So it's the same with ski technique. Yes. In some body positions you have more influence of how you will adopt your center of gravity position than in others. Yes. So that's why we are, let's say, not standing completely upright but our knees are bended during skiing because then we can change with without changing lean angle, that's— we can change angulation of the ski. So the ski turn goes like this. You go, you start by leaning inwards. I'm talking about carving or skiing. Skiing turn doesn't make big difference. Yes. You tip inwards, so downslope, and you hope that the ski will follow and start to turn so that it will catch you up on the, on the other side of the turn. Yeah, it's like riding a bicycle, it's the same physics. Yes. Now if you ride a bicycle straight and you want to make left turn The question is how you turn your steering wheel. Wheel, yes. Left or right? Right, yes.

Yeah, off balance to fall inside.

Yeah, yes, yeah, it's the same with skiing. So yeah, and then you coordinate how fast, how tight your turn is to avoid falling. Yes. Inside or outside, it doesn't matter. Yeah. And you coordinate that by angulation of the ski. Yeah. Sometimes your speed is high enough, so it adds up everything. If you are too slow and you lean too much in, then you have to shorten your turn, you have to increase angulation, and in that case, you push your knees inside, you increase angulation that way and shorten the turn. Yes. And so on. It's a lot of combinations of movements in skiing involved to perform a perfect turn. Yes. That's why robots don't ski.

Yes. Yeah, yeah, that's right. When you look at the videos on YouTube of robots trying to just do a simple race they can't even make it really past the first gate.

Yeah, yeah, but actually they, they do ski, but they don't. So if they use algorithms, like, uh, let's say mathematical algorithms to predict what will happen, yes, then they don't ski. But I have a friend of mine who is in this kind of experiments. He made different kind of program so holistic way, so with neuron network and that kind of stuff, I don't understand. Yeah, but that robot taught himself to ski. Wow. It started with falling all the time and then slowly improved a little bit. Hmm. Have you, have you seen—

has he got video footage of this anywhere?

I I think I can find it. I have a book, he made a book on this, on robotics. I'm not sure if I can find it in short term, but—

If any, if you do one day, I'd love to see that.

Yeah, yeah, I will ask him to give me this because this is the only way, let's say, complex movements like skiing can be learned. Yeah. So just by trying, falling.

Yes. That's it. Yeah, just like how we learn.

Yes. Yes. Yeah. On the other hand, it is very interesting to see kids, how they ski. I have 3 kids. Now I have granddaughters, 3 of them. They all ski. Mm-hmm. You give them skis, let them enjoy, and that's it. And they will learn how to ski without interfering from ski teachers or whatever. Yeah. They will do it their own way. Yes. But they have all in common. Yeah. Kids will always ski with their center of gravity backwards. But not because they are afraid. Yeah. But because this is the position that releases, so it makes the ski unstable. So he can make a turn whatever he wants, whenever he wants. Yeah, okay.

So center of gravity behind that sweet spot makes the ski unstable. So that's the easiest point to manipulate the ski from. Is that, would that be correct?

The ski will turn the fastest for every— so first of all, they are not using parallel technique but a little bit wedge. Yes, yeah, pizza. Yes, they call it in America. Yes. Okay, and by balancing the center of gravity between two skis, you get, let's say, possibility of steering, but you are always backwards, just move the center of gravity left or right, and that's it, and it will work.

Yeah, yeah, okay, yep.

So it's when you see all types of skiers, all types of ski techniques, it's very hard to discover what is the common point of everything. So that's why it took me snowboarding to discover the basic idea what is going on. Mm-hmm. Yeah, in skis, on skis, on two legs, it's just too complicated to observe.

Yeah, yeah, yeah, definitely. I can understand that. So now, so back to this, I guess, talking about human movement on skis again, because something, I guess I've found is stepping off skis, people that end up coming to see me because they're in pain, so physical pain, their knee or whatever, often the variability and options that their body has to move has kind of been reduced down from what it used to be before they were injured. And so they're kind of stuck in not having as many options to move, and then that has resulted in the body giving them pain signals because perhaps it's, it's wearing out a particular movement pattern, or it's the body's worried that it's going to wear it out or something, and so damage is occurring. So back on snow, my— something I guess I like to think about, or perhaps maybe theorizes that really good skiers have every single joint and option movement available in, in, in all dimensions of movement to their disposal. So then whatever situation comes up, whether it's a bump in the snow or change in snow texture and surface, so that, so that maybe the ski starts skidding or accelerating in front of them or whatever it is, they have all the options, which then they will learn the most efficient one to rebalance or recenter, rekindle, line, align themselves to get the ski working again. Would you agree with that statement, or—

Yeah, so as I said, 10,000 repetitions to learn something. I can say from my own experience, I didn't study from the binding off, so, higher than binding level. I didn't study everything, I have just some ideas, but I can say from, say it from my personal experience, comparing to my wife, we are skiing together, but she depends on me when we go off-piste, that I can read the snow, snow type, Sometimes it's just changing inclination for 5 degrees towards or in the other way of the sun and it will change the snow completely. So after all those years I can read it. Yes. Now I can ski like, let's say, quite good. She's avid skier but she cannot read the snow.

Yeah, so that's a very interesting part of experience.

So yeah, when you are skiing on the ski slope, you see that what kind of snow is coming, what is going on, and you are prepared because you have made your share of repetitions. And the good skiers, they see, they know, they are prepared in advance what will happen. Because reaction time of human body is, let's say, 0.1 seconds. So from input to output, if you are, let's say, avid athlete, but if you are a normal person, it's 0.3, 0.4 seconds. Yeah, yeah. And if you can read in advance what will happen, so you are in advantage.

Yeah, yeah. It's interesting, I think I've said this to one person before on the podcast, but There is a physiotherapist out there, so, and a neuroscientist who talks about one of the main functions of, of our brain is prediction. So, like what you're talking there, it's learning to predict outcomes well before they happen because that makes you feel some level of, I guess, certainty and confidence to do or face whatever is coming coming towards you. So that, that, that story you just said, I guess, illustrates that point. Like, she's not confident in predicting almost, or she can't predict very well these changes and what will happen.

I have an interesting, very interesting story on this prediction stuff. Yeah. Yeah. We have a young dog now in our house, and in wintertime, he was going out to pee. Yes. More or less. And it was wet. And when he was going back upstairs, it was slippery and he fell, hurt himself badly between legs, you know. And next time he went out to pee, it was wet on the bottom of stairs. He stopped, think a little bit, and then he went up backwards. He predicted. Yeah, yeah. And he logically concluded that if he's turned downstairs, then it will not be slippery. Yeah, yeah. So, and it took, it took him one week of going backwards to turn again.

Yeah, yeah.

We are all predicting what will happen. That's right. Making conclusions and logical, more or less logical conclusions.

Yeah, based on that experience.

On experience. And one of the things about experience, when I was working in Elan the second time, it was in late '90s, We were working with Nordica company, which was at that time owned by Benetton, and they hired a guy who was working for Piaggio before. And once I mentioned this is because of our experience, and he had a perfect answer to that. He said, if you are claiming experience then you are proving you don't have a clue. And when you think about it, that's very true. Yeah. So if experience shows this and this and this, you don't have a clue what is going on.

Yeah. Yeah. Because I guess—

Go ahead, sorry. Ski business is close to that. Yes. Yeah. It's based on experience.

Yeah. Yep. Yeah, interesting. So Yuri, I was just thinking, are there any more topics? There's a couple more questions I was thinking of perhaps asking you, but I don't know if there's anything you thought would be interesting to bring up, perhaps from, I don't know, from working in the factory, from the developing prototypes, any kind of, any funny stories or any really bad accidents that, you know, through trialing something or whatever? Is there anything you thought would be worth bringing up?

So, for example, when I lost, let's say, confidence in, or let's say, confidence in ability of ski racers to test skis. Oh, really? This is an anecdote. Yes. So, We had in Elan in late '80s, we had a racer, a girl. She was world champion in slalom in Vail. She won, Matea Svith. She was top skier. You don't get much better than that. Yeah. And she complained about skis. They are not good. They are not good, not good, not good, not good, not good, and so on. Then we made prototypes. 6, 7 pairs of prototypes, and she went testing. And a serviceman who was, let's say, experienced, and he, he knew about those problems, he gave her one pair of ski and second pair and third pair, and she returned, not good, not good, not good. And then he took the old pair which was not good at the beginning, and said, this is something else, this is a very new pair, we tried something special on this. And then she tested, returned, and that's it, that's what I want.

So it had to be, to her, it almost had to be someone put all this effort in and it was special and, and they were really making an effort. Until they made enough effort for her, she wasn't going to say any ski was good. Yeah, exactly. Yeah, yeah. Humans. Yeah, yeah.

Because we are not measuring, we are feeling. Yeah, yeah. Feelings are, well, let's say deceiving.

Yes. Yeah, yeah. So Yuri, one thing I was going to ask Did you delve into ski boot theory or production development research? Like, did you have much to do with that at all, or have you taken any interest in that? Actually, no.

I was in, uh, let's say, working with a company which produces ski boots, but I was not involved in ski boot development at that time. I was in completely different parts of making foot scanner, 3D foot scanner and software for matching shoes to feet and so on. Yeah, yeah. It was interesting project, but nothing to do with ski boots because you cannot change ski boots, whatever it comes out of the mold. That's about it. Mm-hmm. And, uh, there I learned something, uh, let's say, also about feelings, uh, that you cannot fit proper size of the footwear to women. Hmm. The look will always prevail. However uncomfortable the shoe might be, look will prevail.

Look will prevail. So, I mean, because have you heard of David McPhail, or the guy from Whistler who has a blog about— he talks a lot about ski boot setup. And have you heard of him?

No, I never followed ski boots a lot. One of the reasons is when I was testing professionally, I learned that if I want to feel the difference between skis, I have to unbuckle.

Interesting. That— yeah, you got a lot more feeling or sensory feedback with boots undone.

Yeah, yeah, uh, of course I'm doing a lot of tour skiing and tour ski boots are not as rigid as Alpine ski boots. So I learned from tour skiing that I have to unbutton my racing boots to really feel. Otherwise you have, I say, the connection between your leg and the ski, it's too stiff to feel the minor differences in— yes, skis, yeah, properties.

So that's what this guy, I guess, in his blog, he, he's trying to get across to people, is that most ski boots dull this. Or maybe not necessarily ski boots, ski boot fit, custom orthotics sometimes, certain liners, just the the interface is disrupted and altered and sort of deadened through the— through a ski boot. And he's sort of has developed— he went— he did some prototype work to develop a new type of ski boot that interfered less and allowed the human nervous system to sense more what's going on between the snow, the ski, and the skier. And it showed— he, in his work, it showed up that there was a really quite a measurable difference, and muscle activity was heightened in, in sort of postural muscles that adjusted that fore and aft balance. And I guess to me, coming back to your point of that, to make a ski work and to carve is the ability to kind of keep finding that sweet spot and know how to move kind of maybe either side of it to adjust or break it away when needed and lock it back on when needed. So then your ski boot ideally would not interfere with how you sense that.

Yeah, I didn't think a lot about that, but, uh, I see a problem with, let's say, too weak connection. So, you have different snow types, you have different snow conditions, and this also influences how this interface or connection of your body to your equipment works. The problem is only in very hard icy surface. Then, so racers, they have two ways of dealing with this situation of when you get this skid slip vibration. One is, uh, I say, to make the ski very stiff, and the second one is, uh, to buckle all the way to squeeze your feet inside as much as possible. And then as a result, with your muscles— they have a lot of muscles, believe me— make your body from the, from your foot to your hip, rigid system. And this will add mass to the system, and this will change the frequency of vibration. And that's how they deal the system. Yes. You add mass to the system, so if you unbuckle, then there's just a mess of ski and binding vibrating and ski boot. Yes. And your leg, your foot inside is loose, so it will go off their own way. But racers, they do add mass by adding this stiff connection. Yes, buckling up and locking muscles of their legs.

Now, so would you say that almost comes under then the, like, impulse and impulse or, you know, force of one object into another can be changed through the stiffness of the material. So, as in, if you hit, like, for instance, as an analogy, if you try and hit a nail, a metal nail with a rubber mallet, so the material being rubber, as you hit it, some of the energy goes into the rubber because that material is not stiff. And so the nail won't be pushed into the wood as hard. Whereas if you put the same force with a metal hammer against a metal nail, the connection will go through and it will make the nail penetrate through the softer wood. So, is it almost like saying the same thing with a ski racer? They're stiffening the connection with the equipment to make it penetrates.

Yeah, but I would, I would make a little bit different analogy. Use a metal hammer in both cases. Yes. One, one's with a rubber handle. Okay. Yeah. So, because it transfers, so the interface between outside world and your system is the same, so it's still edge. Yes. Icy surface, but in one case, the forces from the interaction go through the system a different way than in another case.

Yeah, okay. And so the, the, so you have to be, if you hit with the full metal hammer, no rubber handle, the person just needs to be stronger to be able to deal with that?

Yeah, yes, so it's larger mass involved, uh, otherwise you, you must separate masses of your head of your mallet and from the mass of your hand and your handle.

Yes, yeah, yeah, from because of the vibration.

Yeah, vibrations are very complicated, so I don't think that I understand vibration. Maybe I'm scratching the surface a little bit of vibration, but otherwise, no way. Guys in aerospace industry, they understand this, this so-called modal analysis. It's very complicated. Yeah. And they have, let's say, media which is air. It's a little bit simpler than snow.

Yes. Yeah. Yeah. Totally. Okay. Well, I, I've really enjoyed chatting with you, Yuri. It's been quite fascinating, helped to sort of clarify some things and, and simplify some things and then also confuse some things for me too, which has been good. Yeah, it's really, it's just made me think. And yeah, I really appreciate your expertise and knowledge on the subject. So, uh, yeah, thanks, thanks very much for your time. I don't know if there's any other parting— oh, that would be my last parting thing, because a lot of ski instructors listen to this. Do you think, as a final kind of takeaway note, what would it be you'd say they should understand? Because I think a lot of the time ski instructors perhaps confuse students through just talking about technique without letting the student understand that really skiing is more about how the ski— I mean, a ski turns through its interaction with the snow like we talked about in the beginning. So would it be getting them to understand that as opposed to getting always bogged down in technique?

But I understand, uh, ski teachers, uh, that's their business. So they, they have to be more clever than their pupils. Yeah, their students. Because, and, uh, let's say making us think more complicated will add to their business. Well, frankly speaking, you don't need a ski instructor. If you are young enough, well, at least athletic enough, you can go out and start skiing on the beginner ski slope, learn by yourself. And any skier, or every type of skiing is good type of skiing as long as you don't hurt yourself. Yeah, it's about enjoyment outside on the snow. In the fresh air, in nature, learning new things by yourself or by help by others, but don't overcomplicate. Uh, this is, uh, I believe skin instructions are too complicated then, but I understand them because they must make money, they must make living out of it. So they learn this and this and this and this and this and this, a lot of stuff which is not necessary. So mainly I would suggest that ski instructions should be as simple as possible.

Yeah, would definitely agree with that.

And because formally I don't have any education in skiing. You know, I don't have any license of ski instructor, any certificate that I know how to ski. Yeah. And I can ski, okay, and at the end point I have changed the way of skiing in history 20, 30 years ago. Yeah, yeah, yeah. Without understanding ski instructions. Yes, yep, yeah.

So that's my point, dude, like, because I've definitely found it just a very valuable thing to just always put, you know, the fact that it's, you know, how this ski interacts with the snow is just, is, is probably the most important thing to understand and keep in the back of your mind at all times.

And sort of, yeah. Referring back to robots which learned how to ski, you learn by experience. Yeah. You cannot learn by theory. Yeah. Yep. Excellent.

All right. Well, uh, I will let you get on with your day, but thanks again, Yuri. If you just hang on the line, I'll just finish the recording now, but yeah, I'm sure the listeners will have really enjoyed that. So yeah, thanks very much.

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