You turn the skis - vs - The skis turn you

[cantunamunch]

False dichotomy. Both happen every time there is a 'turn'. We can demonstrate this by putting our skis on and sitting on a tire swing with our legs hanging free.

If the way we use language makes us think Newton's third law can be violated, then the fault is in the way we use language.

 

[karlo]

I think that the answer depends on what turn is, and what type of turn it is. What is it when "we" turn? Here, I will define it as the COM traveling in a an arc, any arc.

Rotary turns, not carving, barely on edge if at all:
We turn the ski, by rotating it with our legs, rotating our legs at the hip. In the course of that, we will or will not turn. If its pivot slip to pivot slip, then we do not turn; hence, the question of whether the skis turn us or we turn ourselves is moot. If we allow the skis to carry our COM side to side, then the vectors of travel, which include downhill travel, means we turn. Because we allow the skis to carry our COM side to side, we turn ourselves, not the skis.

Short Turns by Carving, without rotary.
We do not turn the skis. The skis turn themselves, because we have placed them on their edges and the shape of the ski, sidecut plus bend, turn the ski, as their designer intended. Whether or not we turn, like the Rotary case, depends on whether or not we allow the ski to deflect our COM side to side. If not, we do not turn. If so, we turn ourselves, because we allowed the skis to deflect our COM

Medium and Long Turns, Carving, no Rotary:
Same as short turn, the skis, with their side it and bend, turn the skis. (We tipped the skis, but if the skis did not have side it and/or could not bend, they would not turn.) For medium and long turns, it is impossible for the COM not to be deflected or carried side to side, so we turn; we cannot not turn. We chose to make a medium or long turn, so we turned ourselves, not the skis.

Do I think about it when I ski? Yes. I carve more than using rotary. I think of making the skis turn by tipping them on edge, but only in terms of setting up the conditions in which the skis turn themselves. I always think where I want my COM to go. I have full control of that. I turn me, not the skis.

I teach kids. I do not discuss that topic. My main focus is control of speed; fall-line-awareness; using a turn to control speed. Kids are not going to make turns that do not turn them(COM travelling in an arc), unless they simply go straight down the hill, in which case they are neither making turns nor, in my view, skiing. Kids will always think they are turning the skis, or not turning the skis. In the case in which the skis turn "on their own", not by the kids' volition, they will simply think "I fell".

Never heard of this term before.

 

[karlo]

The more edge we employ relative to rotary, the more the ski will deflect away from the fall line with the result of causing the skier to turn

Except the carved turns banging straight down the fall line in which the deflection of skis is kept tight enough, by the skier, such that the COM does not get deflected. Any deflection of skis is within "legs'-reach"

 

[Steve]

This is a bit of a semantic thing, but I think 4ster's wording is best. It's not the skis that turn us, it's the forces that turn us. As he said we manipulate the skis, we put them in the right position and they turn due to the reaction of forces.

It's like asking does the hammer drive the nail or do we?

 

[mister moose]

The question is unresolvable if you get into philosophical instead of physical. This is where thinking, intent, and control come into the discussion.

If you stay with physical, I think you can be more definitive. I agree with cantunamunch, Newton's laws don't change on the ski slope or on this forum.

So lets start by defining "turn".

1). Turning is a rotary action about our vertical axis. We can do this standing still, and we don't need skis to do it. Whether we rotate at the neck, shoulders or hip, we do it ourselves. We also can apply rotary to our skis. We can turn our skis while in the air. Other things will happen, but we can turn our skis about an axis. We generate the force, ie our muscles generate the forces at work. We turn the skis.

2) Turning is a deflection in the direction of our velocity. This is different. This is the case of using external forces. Whether you cause it by tipping the ski, rotating the ski, or grabbing a passerby, you are using external forces. Many are arguing technique, what you employ to deflect the mass. That doesn't matter. The forces employed are still external. In Karlos's "leg reach" example, there is no deflection of the mass. There is no rotation of the mass. You are changing the path of motion of the feet, but you are traveling in a straight line. Traveling in a straight line isn't turning, is it? It's only turning parts of you. and even then it is a turn to a limit and a return to equilibrium... Not the same. You might turn the steering wheel in a car, but the car changes your velocity and changes your direction. The velocity of your mass changes direction from the forces transmitted through the car seat. The skis turn us.

 

[Uke]

4ster and others,

The ski is just a tool, I agree. It is the tool that lets me go where I want to go. Without it on my feet I would be unable to go where I want to on a ski slope. Can anyone tell me how they would turn without skis on. 4ster brings up forces that move us around. Those forces wouldn't exist nor would we be able to direct them in a useful way without the ski. Seems to me that what is being said is 'skis don't turn me but without skis I couldn't turn'.

If you go left and you go right on any slope but the easiest beginner hill it is the ski that allows you to do that especially at more than walking speed. In my book that is the ski turning me.

uke

 

[Skisailor]

As a student, who has a history of Z turns that is perpetually trying to fix that, I would tend to think of the skis turning me as a good thing. You still have to create the movement and setup to have the skis turn you but in my mind me turning my skis is me forcing them around. Which is needed and works in certain circumstances and is totally a useful tool to have, but given my focus of not rushing my turns.... for me now, it's a bad thing.

Hi Timymoose!!

I totally understand where you're coming from with worry about forcing them around too quickly for the turn shape you are intending. But I really hate to think you might be throwing out the baby with the bath water, so to speak. Steered turns - which blend rotary action (the ski tail displaces more than the tip) can be a result of actively turning our legs or actively putting them on edge and letting the engaged sidecut turn the legs, but really it's almost always a blend of both.

I hope you don't throw out the the muscular, turning your legs aspect of a turn but instead just learn to modulate the timing and intensity of that action so that it doesn't happen all at once at the beginning - the Z turn.

 

[JESinstr]

Although this thread was started with good intentions, A discussion over the meaning of the word "turn" , in the context of skiing, is somewhat ludicrous.
Comparing turning (rotating) your skis to a ski turn (traveling in forward on a circular track) is not like comparing apples and oranges, it's like comparing apples and rocks.

And if what Mike King said is true about " trainers at Snowmass spent several training days on this topic with, as far as I know, no consensus on the outcome", I fear for our industry.

 

[LiquidFeet]

This thread is generating an interesting hodge-podge of responses. People are all over the place with the phrase, maybe depending on whether or not they have heard it in the context of a technical discussion before. Fun! I like this kind of discussion.

For people who would say that skis can turn the skier without the skier turning the skis, and without the skis carving an arc-to-arc turn, how so?

 

[Skisailor]

I think that the answer depends on what turn is, and what type of turn it is. What is it when "we" turn? Here, I will define it as the COM traveling in a an arc, any arc.

Rotary turns, not carving, barely on edge if at all:
We turn the ski, by rotating it with our legs, rotating our legs at the hip. In the course of that, we will or will not turn. If its pivot slip to pivot slip, then we do not turn; hence, the question of whether the skis turn us or we turn ourselves is moot. If we allow the skis to carry our COM side to side, then the vectors of travel, which include downhill travel, means we turn. Because we allow the skis to carry our COM side to side, we turn ourselves, not the skis.

Short Turns by Carving, without rotary.
We do not turn the skis. The skis turn themselves, because we have placed them on their edges and the shape of the ski, sidecut plus bend, turn the ski, as their designer intended. Whether or not we turn, like the Rotary case, depends on whether or not we allow the ski to deflect our COM side to side. If not, we do not turn. If so, we turn ourselves, because we allowed the skis to deflect our COM

Medium and Long Turns, Carving, no Rotary:
Same as short turn, the skis, with their side it and bend, turn the skis. (We tipped the skis, but if the skis did not have side it and/or could not bend, they would not turn.) For medium and long turns, it is impossible for the COM not to be deflected or carried side to side, so we turn; we cannot not turn. We chose to make a medium or long turn, so we turned ourselves, not the skis.

Do I think about it when I ski? Yes. I carve more than using rotary. I think of making the skis turn by tipping them on edge, but only in terms of setting up the conditions in which the skis turn themselves. I always think where I want my COM to go. I have full control of that. I turn me, not the skis.

I teach kids. I do not discuss that topic. My main focus is control of speed; fall-line-awareness; using a turn to control speed. Kids are not going to make turns that do not turn them(COM travelling in an arc), unless they simply go straight down the hill, in which case they are neither making turns nor, in my view, skiing. Kids will always think they are turning the skis, or not turning the skis. In the case in which the skis turn "on their own", not by the kids' volition, they will simply think "I fell".

Never heard of this term before.

Hi Karlo - yeah we definitely have different definitions going on so it does help to clarify. More later - but I have a much more narrow definition of carving. A true carve for me is riding the arc of the ski - its sidecut - where tail follows tip exactly and does not displace at all relative to the tip. We can only influence this turn radius to a relatively small degree and that will be influenced by the skier's weight and the longitudinal stiffness of the ski - plus the forces we generate through speed to further bend the ski. My daily driver K2s carve a 13 meter arc. I can tighten that up a bit but I'm not calling the 2 meter short turn - even if very edgy and with rotation in the air - a carved turn.

I think some are calling this true carve park and ride, but I define park and ride as someone who is riding that arc without fiurther movement. Like a statue. Riding the sidecut with continuous movement using flexion and extension and with small adjustments in counter and fluid transitions - that is not static park and ride for me. Totally different.

So there is no such thing as a short radius "carve" for me. I would call that a dynamic short radius turn that is a subset of steered turns with a high ratio of edge to rotation.

 

[karlo]

Fun!...

For people who would say that skis can turn the skier without the skier turning the skis, and without the skis carving an arc-to-arc turn, how so?

Yes, fun. Much better than reading the Sunday paper and trying to figure out what's true and not true. Well, Labor Day Weekend, I've had breakfast, I've taken the dog out to walk 2 miles and played fetch with him, and until my son gets his a$$ moving and finishes breakfast, my day is on hold. So what better place to spend that time than here.

Let's consider an extreme case, absolutely straight straight skis. Put them on edge and we carve a straight line. We, our COM,, will not turn. We will go across the hill with a downhill component, straight across. Now, rotate (turn) the ski with our legs, to turn the tips downhill, we can create a new trajectory, a turn. A continuous rotation, through the fall line, across the hill the other way, we have completed a full skiing -turn. In this example, to me, the skier both turned the skis and turned him/herself, with the assist of that other force of course, gravity.

Tipping a shaped ski, to me, that's different. To me, as soon as we rely on the ski's design to turn, the ski turns us. But, then, there is the philosophical point of view that includes intent, as Mister Moose points out makes the question tougher. If the shaped skis were not a gift, not handed to us by the resort rental shop, nor not used per an instructor's or coach's instructions, and, instead, are deliberately chosen by ourselves, for its shape, its stiffness and torsional rigidity, to enable ourselves to arc the ski in specific ways, then did we turn ourselves?

A true carve for me is riding the arc of the ski - its sidecut -

So there is no such thing as a short radius "carve" for me. I would call that a dynamic short radius turn that is a subset of steered turns with a high ratio of edge to rotation.

Yes, if the ski can't be bent much, I agree. But, then, when I'm teaching, and I teach kids at a level at which they are learning to parallel, I use more flexible skis so they bend more, and can give me a shorter turn, a carved-turn radius that is shorter and can be done at slower speeds. But, absolutely, if ski bend is taken out, we need to use rotary to shorten the turn... and, then, I think we help the skis turn us! We and the skis are a team. Better yet, we are one. See my entry in Pugski Word Contest. For that species, the skis are to it as our feet are to us.

 

[4ster]

Let's consider an extreme case, absolutely straight straight skis.

Do these imaginary skis have camber?

 

[HardDaysNight]

My daily driver K2s carve a 13 meter arc. I can tighten that up a bit...

A 13m ski tipped to an angle of 45 degrees, certainly within the ability of a decent recreational skier, will carve a turn with a radius of approximately 9m. Tip it to 70 degrees and that is reduced to about 4.5m. Beyond a certain speed, skidding the ski has the effect of opening the turn radius not tightening it.

 

[Bad Bob]

You turn the skis.

You initiate the turn. Even in the purest of carved turns the skier causes the ski to function. A competent skier will skid, slarve, swivel, pivot, carve, or a mix there of. The ski is a tool that functions upon your input that will be mitigated by the environment and conditions you are in.

The ski can only act with input.

 

[mister moose]

You turn the skis..The ski can only act with input.

This is control, decision making,not physics. Tipping and pressuring is not turning. The skis turn you, they change the direction of your velocity.

 

[Mike King]

Although this thread was started with good intentions, A discussion over the meaning of the word "turn" , in the context of skiing, is somewhat ludicrous.
Comparing turning (rotating) your skis to a ski turn (traveling in forward on a circular track) is not like comparing apples and oranges, it's like comparing apples and rocks.

And if what Mike King said is true about " trainers at Snowmass spent several training days on this topic with, as far as I know, no consensus on the outcome", I fear for our industry.

This thread is generating an interesting hodge-podge of responses. People are all over the place with the phrase, maybe depending on whether or not they have heard it in the context of a technical discussion before. Fun! I like this kind of discussion.

For people who would say that skis can turn the skier without the skier turning the skis, and without the skis carving an arc-to-arc turn, how so?

There's no reason to fear for the industry. A lot of the issue is semantics, as so often is the case in the ski industry. Clearly, skis do not turn themselves -- put a ski on the snow without a brake or restraint and it will likely seek the fall line and proceed downhill without turning. There are, however, degrees of causing the skis to turn having to do with dirt. That's more of the issue and the cause of semantic problems. And @LiquidFeet noted the same by observing the diversity of responses in this thread.

Mike

 

[François Pugh]

Does this phrase resonate with you?
Do you ever think about these two things as you ski?
Does your teaching ever reflect anything embedded in this phrase?
If you take lessons or take part in training sessions, do your coaches ever refer to this phrase?
If yes, what does it mean to you and how to you deal with it?

Thanks for opening up an interesting discussion.

On the face of it, this expression implies to me a demarcation point in skier development. It reminds me of a skier level description I came across on the web, and at first I thought this was it, but upon further reflection I realized the demarcation point I had read that resonated with my early development was actually "use tipping the ski as your MAIN means of turning.

The right way to take this expression is, IMHO, on first glance interpretation, and not to overthink it. Where is the effort? If you are putting a lot of effort into turning your skis, so that they can effectively turn you then you have a lot to learn. If on the other hand you make minimal effort giving your skis proper input, and relying on their design to turn that minimal input into maximal turning force you have figured out a lot more.

As a decades-long experienced carvaholic, I am surprised at the number of folk who have a gross misunderstanding of what is possible with a pure arc-2-arc carved turn. Sure, set up and initiation are important and make things a lot easier, but you can always (if you know how) change your turn radius on the fly, and are not limited to what you originally intended at initiation. Nor does the radius of the ski fix an inflexible turn radius. Yes, the are still limits; you will not pure carve arc-2-arc 2 m turn on an 30 m ski, and you will not make a pure carved 40 m turn with a 13 m ski. You can still alter the turn radius of your turn and make a pure arc-2-arc turn at a range of speeds and a range of radii from slightly longer than the turn radius of the ski (thanks to its flexibility) to much short than same. I thinks some of the misconceptions stem from only skiing in soft snow, and some from only skiing in hard snow, but that's just, like, my opinion man.

I once found a high school student playing with a toy plastic skateboard, instead of paying attention to his lessons. The toy was ingenious. It effectively mimicked the action of trucks on real skateboards. I wish we had a plastic toy ski with exaggerated side cut we could play with on a hard carpet-like surface. That toy would illustrate how to carve a turn, and show the radius of that turn on a hard surface would be smaller than the side-cut radius, and depend on tipping angle.

Even a straight ski would be bent under load when skied in soft snow, and tipping it would cause a turn.

In truth it is always a bent ski's edge and base that cause a turn due to steering angle of the edge/base with respect to current direction of travel. Whether we rotate that edge to a steering angle and let the edge turn us, or tip the ski and allow the resulting steering angle and edge to turn us (integrated piece-wise along different portions of the edge), it is still the edge/base of the ski that turns us with the force generated between the snow and the ski.

The problem with the original on the face of it interpretation is that in certain circumstances, e.g. deep snow rockered wide skis, it is just as easy to swivel to a bit of a steering angle and then before tipping, while in other circumstances, e.g. typical groomer with a bit of snow on it it is easier to tip first and forget about the swivel. Swiveling a flat ski is easy (especially with a lot of rocker) and swiveling a highly edged ski is hard, timing of tipping and swiveling is important! Realizing how tipping a ski changes it's effective steering angle as it moves forward allows us to save energy by not needing to work to turn (swivel) the ski, but to let the ski's design allow a minimal tipping effort to make the ski turn.

That's the beauty of skiing, there is always another way to do something, and more degrees of freedom.

 

[JESinstr]

There's no reason to fear for the industry. A lot of the issue is semantics, as so often is the case in the ski industry. Clearly, skis do not turn themselves -- put a ski on the snow without a brake or restraint and it will likely seek the fall line and proceed downhill without turning. There are, however, degrees of causing the skis to turn having to do with dirt. That's more of the issue and the cause of semantic problems. And @LiquidFeet noted the same by observing the diversity of responses in this thread.

OK I give!!!! But just to add a little sanity to this thread, would it not be appropriate to first define the term "Turn" and then proceed with the stated topic?

 

[Skisailor]

A 13m ski tipped to an angle of 45 degrees, certainly within the ability of a decent recreational skier, will carve a turn with a radius of approximately 9m. Tip it to 70 degrees and that is reduced to about 4.5m. Beyond a certain speed, skidding the ski has the effect of opening the turn radius not tightening it.

Karlo and I were talking specifically about short radius turns. Not 20 foot arcs. And I must admit, not being a race coach but being an instructor of recreational skiers whose goals are generally about skiing with more control and with less effort in big mountain, off piste terrain, neither I, nor literally any of my students, are in the habit of being on significantly cambered slalom race skis nor of practicing tipping to 70 degrees. So . . . . I stand by my original statement.

 

[Skisailor]

Meant to add:

We have to remember that a 4.5 m radius is still a 9 m diameter turn (about 30’) and can only be generated under the assumption that you are able to create that 70 degree edge angle throughout the WHOLE turn - from edge change to edge change.

Even with a recreational skier tipping to 45 degrees we are talking an 18 m diameter.

My 13 m radius ski makes a 26 m diameter (about 78 foot) arced turn which I can tighten up a bit at speed.

But I'm not teaching ski racers. So my question would be what do we do if we need a 180 degree 10 foot diameter turn? It will not be a carved turn. It will be a steered turn with a high degree of rotation added to the skill blend.

That was my main point with Karlo. A true short radius turn is not a carved turn - we were clarifying each other's definitions.