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# Ski technique - Page 30

Quote:
Originally Posted by razie

Yeah... so this skier is on average 5-6 times lighter in transition than at the apex. Yet some here still, after 50+ failed arguments, all easily proven false, want to claim that is heavy.

Yes, Razie, I gave you that out.  If you are defining heavy as the apex of the turn, then certainly the transition will be light.  Though, this is not what Phil or CTkook meant, because they know there is no centrifugal force during transition.  If it's a simple misunderstanding of words, then fine.  2/3 of maximum weight as a mean is heavy enough especially given that it's distributed.  We're not proving that every transition is heavy, only that some are.

Here's a quote from Rick posting right here on Epic, so you can see it's not just the people dumb enough to keep arguing with you that understand these things.

" Metaphor, for what purpose are you trying to unweight in the first place?

Up unweighting and down unweighting were pervasively used techniques in the pre shape ski days to allow the skis to be easily pivoted/redirected coming out of the transition (Pianta Su).  Now a-days, arc to arc turning is more feasible in more situations, and in those turns unweighting is not necessary.

And,,, just for clarity,,, release does not equate to unweighting.  OLR and ILE just transfer pressure from one ski to the other, they don't eliminate it.  Unweighting does eliminate it. That's it's purpose"

Razie, go lick your wounds and come back another day, and maybe you'll win next time, but this horse is dead.

Quote:
Originally Posted by The Engineer

...  We could post lots of videos showing weighted transitions, but how do you prove it's weighted 2/3 or 1/3 from the videos?  ...

I agree with this statement insofar as I'd be off by a reasonable margin trying to guess exactly how much weight is born during transition.  I disagree however insofar as, outside a certain margin of error, I believe it's possible to clearly tell whether weight is born during transition, or not.

For instance, here,

we have extensive footage of a pretty good skier who's clearly not trying to "float" every transition.  Moreover, I have a very high degree of confidence that her coaches weren't all over her for her failure to show "float" during her transition, either as a goal or an outcome.  They would however have been all over her if the preponderance of these turns had shown floated transitions.

In this regard I would recommend to viewers, for instance, 2:44 of the YouTube where she gets a bit back and loses contact.  Even the very best skiers in the world sometimes do this, it's not a criticism, but if the default movement pattern were instead to lose contact and "float" the transition, and to only have pressured skis right at the gate as Razie for instance has expressly advocated, she wouldn't be racing no more except for fun.

We can do this with real video all day, because these are the movements racers use.  People with on-snow experience can tell that these aren't "floated" transitions, no matter how much social expectations within an internet forum might try to claim that they are or that float is either a goal or outcome of high-level skiing.  Racers do also skid and drift and stivot and pivot and show plenty of unweighted transitions when they have to, but it's simply slower as a default.  Float is cool, freecarving is cool but neither does freecarving require float, and in fact one good test for someone in terms of recreational freecarving is whether they can make overlapping cuts consistently in a way that is inconsistent with float.  But if a recreational skier enjoys a style of carving where they float every transition, that's great, they just shouldn't feel they need to do that because "racers do it."

We have complete "unweighting" in the turn force direction, with the amount of unweighting in the vertical direction adjusted for desired vertical trajectory.

The words stay heavy in transition are directed to a particular purpose (coaches do that), the purpose being to stop anyone from doing the old school unweighting move they would do to faciilitate pivoting the skis.  Not sure how many racers would need that instruction, but apparently lots of ski instructors do.

Quote:
Originally Posted by CTKook

.... they just shouldn't feel they need to do that because "racers do it."

CTKook, do you coach racers?

Regarding your feedback TE: huh?
I have seen you repeatedly make statements showing that you clearly do not know what top coaches say. What do David Chastan, Albert Doppelhofer, Mike Porcher, and Roland Pfeifer say regarding ski technique on the WC? Please enlighten us. With respect to what Mr. McNichol says, you demonstrate a misunderstanding, so even if you had access to the coaches I mentioned previously, it's likely the misunderstandings would continue. I guess this is simply an exercise in futility.
Edited by Pacmantwoskis - 12/30/15 at 8:59am
Quote:
Originally Posted by skiatansky

Quote:
Originally Posted by jack97

Sometimes hearing it from the horses mouth is just as important as seeing it.

Why would Ligety, a multi-million dollar athlete, tell his competitors how he's beating them?

Ssh, it's a secret.  Contrary to what some would have you believe his race skis have camber instead of tip rocker.

Quote:
Originally Posted by The Engineer

Razie, go lick your wounds and come back another day, and maybe you'll win next time, but this horse is dead.

Meh... I was going to let this be, but you had to start with crap like this, eh? You are correct however: this "heavy transition" horse has been dead since you brought it up - it has never lived anywhere except in your vivid imagination... and we've been doing exactly this the entire time:

Like I said - I probably do require counselling for allowing myself to be conned into arguing a non-existent concept.

Quote:

Originally Posted by The Engineer

Quote:
Originally Posted by razie

Yeah... so this skier is on average 5-6 times lighter in transition than at the apex. Yet some here still, after 50+ failed arguments, all easily proven false, want to claim that is heavy.

Yes, Razie, I gave you that out.  If you are defining heavy as the apex of the turn, then certainly the transition will be light.  Though, this is not what Phil or CTkook meant, because they know there is no centrifugal force during transition.  If it's a simple misunderstanding of words, then fine.  2/3 of maximum weight as a mean is heavy enough especially given that it's distributed.  We're not proving that every transition is heavy, only that some are.

But so - I missed this. So you agree the transition is light.

But now you started calling the apex "heavy". The apex is a place in time, on a line, not something that we could you know, categorize as "heavy"...

And in the same breath, you assert that If we call 'light" being 6 times more light and "not light" 6 times less light, that to you indicates that being lighter by 2/3rds on average is actually not light enough, because averages are distributed ???? And you invoke a bell to prove that there is at least one "not light" transition in all of WC racing ? A bell ?

What does that even mean? What does a bell have to do with all this and how does this relate to a dead horse? Oh, I see:

p.s. I heard Phil telling his beginner students there to "feel heavy"... so maybe they're skinny, what do I know.... and he's trying to make them feel better (positive you know coaching thing or other). Or maybe they're all giddy and hopping up and down and he's trying to get them to settle down. Or maybe what Ghost said... I don't know. I don't need to understand the use of one particular word he used once in a 20 minute video, full with other words, more interesting.

Edited by razie - 12/30/15 at 10:34am
Quote:
Originally Posted by Pacmantwoskis

Quote:
Originally Posted by CTKook

.... they just shouldn't feel they need to do that because "racers do it."

CTKook, do you coach racers?

Oh sorry, I wasn't on the ball to help Mr Kook with his understanding.

Here is how I saw a "heavy" notion applied to non-racers in the past: it's a feeling at the end of the turn, of pressure built-up, pressure that you want to manage, you want to reduce and absorb, by flexing... does that jive with your understanding as well? I mean, in a sense, to avoid "being heavy"... I'm guessing that would mean to "be light" to down unweight...?

Edited by razie - 12/30/15 at 11:05am
Quote:
Originally Posted by The Engineer

Razie, go lick your wounds and come back another day, and maybe you'll win next time, but this horse is dead.

IMO Razie won this round. Heck you just agreed that the transitions are light!

Edited by skiatansky - 12/30/15 at 11:42am
Lot's of 'win' in this thread.
Quote:
Originally Posted by markojp

Lot's of 'win' in this thread.

But, it bore out some valuable facts about modern racing technique. Even for recreational skiers, the simple task of thinking about making overlapping cuts on one ski (or simply two skis) is a good takeaway that can help their own skiing, and be a helpful reality check on some of the odd technique advice that is more internet driven.
Quote:
Originally Posted by CTKook

But, it bore out some valuable facts about modern racing technique. Even for recreational skiers, the simple task of thinking about making overlapping cuts on one ski (or simply two skis) is a good takeaway that can help their own skiing, and be a helpful reality check on some of the odd technique advice that is more internet driven.

@razie,if Count Kook hasn't yet driven you to drinking, I applaud you.

I'm convinced Count Kook is just trolling us. There is no way he can seriously mean what he says.

@The Engineer, what you say about ski pressure needed to accelerate a skier along the slope and airtime is slow seems obviously correct to me. But here is what I can't reconcile (besides the numerous clips and pictures of WC skiers). Allow me to define "light" and "heavy" as the strength of the force component perpendicular to the slope pushing on the skier. We feel light and heavy as this force component decreases and increases, respectively. Regardless of my level or how I ski, the time-averaged value of this component must be my weight times the cosine of the slope angle, right?

Allow me to imagine I'm a studly racer. At some point I will be very "heavy" (more than w*cos(slope)).  Therefore, I must be "light" (less than w*cos(slope)) at another point. No? And shouldn't that light or lighter point be at the transition?

Before anyone asks, I hasten to say that I am neither a certified racer nor a practicing physicist. Just a passionate skier who still remembers high school physics.

Quote:
Originally Posted by ChuckT

Before anyone asks, I hasten to say that I am neither a certified racer nor a practicing physicist. Just a passionate skier who still remembers high school physics.

Nobody will ask unless you make claims about WC technique that are far removed from actual WC technique.
Quote:
Originally Posted by Pacmantwoskis

Quote:
Originally Posted by CTKook

But, it bore out some valuable facts about modern racing technique. Even for recreational skiers, the simple task of thinking about making overlapping cuts on one ski (or simply two skis) is a good takeaway that can help their own skiing, and be a helpful reality check on some of the odd technique advice that is more internet driven.

@razie,if Count Kook hasn't yet driven you to drinking, I applaud you.

There is no way he can seriously mean what he says.

It may be a self-fulfilling profecy and maybe that was the plan all along: The more I listen, the more beer I drink, the heavier I get and... oops???

I actually think he is correct just now, perhaps the first time: his advice in this thread is completely in the "internet driven" category, without any references except misinterpreting the one youtube video that happens to mention the H word once in a 20 minutes lesson on getting forward. And his own assertions and mis-interpreting of other videos and internet-sourced texts.

While my advice is "race manual driven" and "multiple book driven" and extensive race-coach and racing training driven, with ample references to a lot of coaching material, including the LeMaster Bible, multiple books and such by the page number etc. Also over 50 supporting photos and snapshots of high level racers and skiers. Including supporting snapshots of myself performing the tasks I actually advise on (hoping that demonstrates some level of comprehension).

If I am to actually add some internet references, I could do that as well... I have grown reluctant though... no shortage of coffin nails lying around waiting to be used, but I now firmly believe that Kook and his followers, whoever still believes any of that, should in fact be heavy through all transitions.

cheers

Edited by razie - 12/30/15 at 7:13pm
Chuck, Your weight is reduced as long as you are accelerating. If you are skiing down a slope at terminal velocity the frictional component adds with the reactionary force to give full weight. If you are heavy at one point, does that mean you will be light at another point? It's all about vector direction. If the increased force that makes you heavy pushes your body up vertically then you will be light when you accelerate back down. This is the up unweight move. But increased pressure from centrifugal force doesn't have to be paid for later in the same way. Also at times when the body is accelerating downward during the turn the skis have lots of pressure from centrifugal force.
If there's a large virtual bump in the turn profile- shape, speed, pitch, then one has to absorb it. Or get air. Even absorbing can mean air or float.

I don't see how one can end a high g turn without absorption unless the transition- well the bottom of the turn, is drawn out due to the particular line followed. There's usually not a lot of space on the steep pitches of a world cup gs. Thus usually retraction. Higher up- flatter section usually, one can be heavier. Not as much of a virtusl bump.
Quote:
Originally Posted by The Engineer

Chuck, Your weight is reduced as long as you are accelerating. If you are skiing down a slope at terminal velocity the frictional component adds with the reactionary force to give full weight. If you are heavy at one point, does that mean you will be light at another point? It's all about vector direction. If the increased force that makes you heavy pushes your body up vertically then you will be light when you accelerate back down. This is the up unweight move. But increased pressure from centrifugal force doesn't have to be paid for later in the same way. Also at times when the body is accelerating downward during the turn the skis have lots of pressure from centrifugal force.

Let's use the plane of the slope (assuming it's perfectly smooth) and its normal as our 3D frame of reference. At any instant, the net force on the skier along the normal axis is Fsnow -Weight*cos(slope angle). Fsnow is the normal component of the reaction force from the snow. Integrating this force over time gives us the velocity of the skier in the normal direction. Since, the skier doesn't dive into the ground below this plane or fly into the air , this integrated value will fluctuate around zero and net to zero. No?

That means the time-average normal force is Weight*cos(slope angle). A skier can't be "heavier" than this all the time.

Quote:
Originally Posted by ChuckT

Let's use the plane of the slope (assuming it's perfectly smooth) and its normal as our 3D frame of reference. At any instant, the net force on the skier along the normal axis is Fsnow -Weight*cos(slope angle). Fsnow is the normal component of the reaction force from the snow. Integrating this force over time gives us the velocity of the skier in the normal direction. Since, the skier doesn't dive into the ground below this plane or fly into the air , this integrated value will fluctuate around zero and net to zero. No?

That means the time-average normal force is Weight*cos(slope angle). A skier can't be "heavier" than this all the time.

You store up energy in your momentum from the Fg*sin(theta) portion of gravity that can then apply a force to increase your pressure.

In that light, according to your question it seems to me that the time averaged force can't be more than Fg (gravity)(see below), but I can't see any reason why it couldn't be more than Fg*cos(theta).

Edit: After thinking about it more, you can have a time averaged force on your skis greater than Fg. Let's say that you are on flat ground with no friction going around a circle. As long as there is no friction you will keep going around the circle and experience centrifugal force that depends on your angular velocity. So, for all time you can have a force greater than gravity. Once you build up that momentum it can create centrifugal force going around a curve that doesn't use up energy, so it doesn't have to be paid for later.
Edited by The Engineer - 12/30/15 at 8:31pm
Quote:
Originally Posted by Tog

If there's a large virtual bump in the turn profile- shape, speed, pitch, then one has to absorb it. Or get air. Even absorbing can mean air or float.

I don't see how one can end a high g turn without absorption unless the transition- well the bottom of the turn, is drawn out due to the particular line followed. There's usually not a lot of space on the steep pitches of a world cup gs. Thus usually retraction. Higher up- flatter section usually, one can be heavier. Not as much of a virtusl bump.

You can absorb so that you reduce the centrifugal force but still have a force greater than gravity. A perfect active suspension going over bumps would absorb in spots and extend (sound familiar?) to keep a constant reactionary force equal to gravity.
Edited by The Engineer - 12/31/15 at 9:53am
Quote:
Originally Posted by ChuckT

Let's use the plane of the slope (assuming it's perfectly smooth) and its normal as our 3D frame of reference. At any instant, the net force on the skier along the normal axis is Fsnow -Weight*cos(slope angle). Fsnow is the normal component of the reaction force from the snow. Integrating this force over time gives us the velocity of the skier in the normal direction. Since, the skier doesn't dive into the ground below this plane or fly into the air , this integrated value will fluctuate around zero and net to zero. No?

That means the time-average normal force is Weight*cos(slope angle). A skier can't be "heavier" than this all the time.

ChuckT, this does bring up another good point.  If the skier is still accelerating down the slope, then the maximum possible weight during transition will be less than 1 body weight, so that 2/3 measurement in the graph discussed earlier could mean that those skiers are even closer to maintaining the absolute maximum amount of pressure during transition.  Sometimes, they may have no more float than they would experience just skiing down the slope.

Edited by The Engineer - 12/31/15 at 7:26am
Quote:
Originally Posted by The Engineer

Chuck, Your weight is reduced as long as you are accelerating. If you are skiing down a slope at terminal velocity the frictional component adds with the reactionary force to give full weight. If you are heavy at one point, does that mean you will be light at another point? It's all about vector direction. If the increased force that makes you heavy pushes your body up vertically then you will be light when you accelerate back down. This is the up unweight move. But increased pressure from centrifugal force doesn't have to be paid for later in the same way. Also at times when the body is accelerating downward during the turn the skis have lots of pressure from centrifugal force.

You don't need up-unweighting to have acceleration, most of it comes from vaulting in high end skiing.

You do realize that what you are advocating is skiing with your CoM at a constant distance from the snow? I don't recall seeing much of that in the WC. I do recall however a study that showed a CoM up and down of about 50-60 cm among the fastest racers. They must be breaking all kinds of laws to be heavy in those transitions. Oh wait, that was also shown. they weren't heavy. (The numbers can be found in the PhD thesis referenced earlier in this thread)

I do see it from time to time from people who overdo a flexed transition, quite common among beginners of the system that CTKook hates so much. Funny, because in essence it he is suggesting that you ski in this way in order to keep heavy with flat skis.

it was not 2/3 it was closer to 0.5 and cos(20)=0.94

Quote:
Originally Posted by Jamt

You don't need up-unweighting to have acceleration, most of it comes from vaulting in high end skiing.

You do realize that what you are advocating is skiing with your CoM at a constant distance from the snow? I don't recall seeing much of that in the WC. I do recall however a study that showed a CoM up and down of about 50-60 cm among the fastest racers. They must be breaking all kinds of laws to be heavy in those transitions. Oh wait, that was also shown. they weren't heavy. (The numbers can be found in the PhD thesis referenced earlier in this thread)

I do see it from time to time from people who overdo a flexed transition, quite common among beginners of the system that CTKook hates so much. Funny, because in essence it he is suggesting that you ski in this way in order to keep heavy with flat skis.

it was not 2/3 it was closer to 0.5 and cos(20)=0.94

I've heard in a number of places that you aren't supposed to bounce like on a trampoline, not just in that Phil video. Vaulting is not the standard for high end racing.

I am not advocating constant COM.

Vaulting and 0.58 weight are not the same thing. It's heavy enough.
Edited by The Engineer - 12/31/15 at 9:49am

@The Engineer, To see things more clearly, I decomposed the force into two orthogonal components, normal to the slope and in-plane which is the centripetal force. I agree with you that the in-plane component does not have to "pay back" per se. However, on ice, I doubt a skier can sustain a large centripetal force without a correspondingly large normal force - she would skid without a sufficiently strong normal force.

Anyway, unless I misread the recent posts, everyone seems to agree that "heavy transition" only means having some pressure on the skis, not really more than 1 G or even close to it. In that case, I have no difficulty believing that WC skiers ideally avoid or minimize the time floating, i.e. complete weightlessness.

As an aside, I always fail to see the point of the trampoline analogy. It may have some pedagogical value, but, besides from the superficial similarity in appearance, the physics bears no resemblance to skiing. Jumping on a trampoline is a transfer back and forth between kinectic energy, i.e. speed, of the jumper and the potential energy stored in the stretching of the trampoline: The jumper decelerates to zero then accelerates again in the other direction. The net force is always in the direction of motion. Not so in skiing. The skiers, good ones anyway, use the skis' interaction with the snow to create forces with a huge perpendicular component (i.e. centripetal) to deflect the motion without reducing speed. There is virtually no potential energy stored in the bent skis like in the trampoline.

Quote:
Originally Posted by ChuckT

@The Engineer
, To see things more clearly, I decomposed the force into two orthogonal components, normal to the slope and in-plane which is the centripetal force. I agree with you that the in-plane component does not have to "pay back" per se. However, on ice, I doubt a skier can sustain a large centripetal force without a correspondingly large normal force - she would skid without a sufficiently strong normal force.

Anyway, unless I misread the recent posts, everyone seems to agree that "heavy transition" only means having some pressure on the skis, not really more than 1 G or even close to it. In that case, I have no difficulty believing that WC skiers ideally avoid or minimize the time floating, i.e. complete weightlessness.

As an aside, I always fail to see the point of the trampoline analogy. It may have some pedagogical value, but, besides from the superficial similarity in appearance, the physics bears no resemblance to skiing. Jumping on a trampoline is a transfer back and forth between kinectic energy, i.e. speed, of the jumper and the potential energy stored in the stretching of the trampoline: The jumper decelerates to zero then accelerates again in the other direction. The net force is always in the direction of motion. Not so in skiing. The skiers, good ones anyway, use the skis' interaction with the snow to create forces with a huge perpendicular component (i.e. centripetal) to deflect the motion without reducing speed. There is virtually no potential energy stored in the bent skis like in the trampoline.
The bent ski is like a spring board and does store some energy, like how a bow can shoot an arrow.  In my opinion, it takes skill to release it without bouncing someone.  That USSA document describes several methods pretty well in their edge release section, starting with the ankles, then knees..., being able to let the COM release from centrifugal force while still edging, independent edging "an indication that edging skills are highly developed."  "This leading or initiation with the upper body is an advanced skill.".  "This "independence of ski edging" is an advanced skill."

Loading the ski and retracting with both legs to bounce to the next turn doesn't take such precise independent edging control, though I enjoy doing it quite regularly.  To stay locked to the snow, I believe it helps if one leg extends while the other leg flexes, and this will require that independent edging.
Edited by The Engineer - 12/31/15 at 1:08pm
Quote:
Originally Posted by The Engineer

The bent ski is like a spring board and does store some energy, like how a bow can shoot an arrow.

If you look at the amount of ski bending, I think you will agree the energy is very small compared to the kinetic energy of the skier. I think there has been at least a thread on this before.

Looking at Graph 6.36 in Reid's thesis, it's clear that the skier is light at transition, much lighter than the maximum force, but not weightless or floating. Let me summarize my understanding to see if I get it right.

1. The ideal is to maintain higher speed for the course. This requires higher centripetal force for the turn at same radius (m*v2/r). This force cannot be sustained, i.e. skidding, unless the normal force is higher, usually much more than 1G for a WC chap.

2. Therefore the COM must accelerate up to generate this normal force to sustain the centripetal force. And then it must necessarily accelerate down. In a carved turn, this happens when the local turning radius is large, no big centripetal force is required.

3. The fastest skiers have their COM move up and down just enough to create the normal force needed to sustain the centripetal force for the course. Less than this, they will skid. More than this, they will be slower. Floating is best avoided when possible.

What do the experts say?

Happy New Year and Good Skiing to everyone!

Quote:
Originally Posted by ChuckT

... Floating is best avoided when possible...

...

Happy New Year and Good Skiing to everyone!

If you're talking racing, yes.

For skills development, working both extremes wouldn't be the worst thing.  I'd mentioned working on carving with overlapping tracks as among other things a good drill.  More or less the reverse would be working on a section of trail where you down-unweight every turn, and a section where you up-unweight every turn.  A summertime analog would be doing laps on a pump track where you jump every roller -- both good conditioning, and your jumps get better, but obviously slow as well.

Racing is an interesting focus, as there are several factors blended together that go into fast runs, of which turn transition is only one.  But yes, keeping pressure as an ideal scenario is obvious enough that it's almost taken for granted in the real world.

https://youtu.be/yFfaeTtl2HY

We're all right! Haha make sure to watch the second run...you'll see almost everything discussed in this thread.
Peace
Quote:
The bent ski is like a spring board and does store some energy, like how a bow can shoot an arrow.  In my opinion, it takes skill to release it without bouncing someone -The Engineer
Not much energy, plus there's usually snow underneath so it's no longer a bow. This was discussed in some detail in this thread like pg 4 on:
http://www.epicski.com/t/119963/why-be-patient-at-turn-transition/90
Quote:
Originally Posted by ChuckT

@The Engineer, To see things more clearly, I decomposed the force into two orthogonal components, normal to the slope and in-plane which is the centripetal force. I agree with you that the in-plane component does not have to "pay back" per se. However, on ice, I doubt a skier can sustain a large centripetal force without a correspondingly large normal force - she would skid without a sufficiently strong normal force.

Anyway, unless I misread the recent posts, everyone seems to agree that "heavy transition" only means having some pressure on the skis, not really more than 1 G or even close to it. In that case, I have no difficulty believing that WC skiers ideally avoid or minimize the time floating, i.e. complete weightlessness.

As an aside, I always fail to see the point of the trampoline analogy. It may have some pedagogical value, but, besides from the superficial similarity in appearance, the physics bears no resemblance to skiing. Jumping on a trampoline is a transfer back and forth between kinectic energy, i.e. speed, of the jumper and the potential energy stored in the stretching of the trampoline: The jumper decelerates to zero then accelerates again in the other direction. The net force is always in the direction of motion. Not so in skiing. The skiers, good ones anyway, use the skis' interaction with the snow to create forces with a huge perpendicular component (i.e. centripetal) to deflect the motion without reducing speed. There is virtually no potential energy stored in the bent skis like in the trampoline.

Well, just to be clear. This discussion started because CTKook and Atomicman claimed that it is a good idea to be heavy in transition, and the way they want to do this is by pushing, including when the skis are flat.

Floating is not weightless, it is a significant reduction of vertical force.

What was claimed was that in High-G turn float is a result of proper movements. Heavy is fast, but it simply does not work in high-G turns with fast transitions.

This is Figure 6.36 from Reid. This is a floated transition, as most are. Anyone who thinks this is a heavy transition must be using a completely different definition of heavy than I am. Alternatively they are smoking some "heavy" stuff.

Your point about using a higher normal force when it is needed is very relevant. I have mentioned that several times in this thread but I don't recollect anyone responding to that.

Quote:
Originally Posted by Tog

Not much energy, plus there's usually snow underneath so it's no longer a bow. This was discussed in some detail in this thread like pg 4 on:
http://www.epicski.com/t/119963/why-be-patient-at-turn-transition/90

I looked through that thread and a number of people had it right, but not Jamt as usual.  I have this technique where I can load the ski through a combination of rotary and tipping to create quite a bit of spring and jump from turn to turn.  I can do it with very little inclination and at slow speeds.  When the ski is bent it pushes back with a force that gives you an extra push when you jump.  You can feel the difference for different skis that are stiffer.  Jamt probably measured the force in the middle with the tip and tail held, saw a small value and ran with it, but you have to move the grip point further up.  Having the ski on the snow makes no difference, if the ski is bent, it's pushing back with force.  When a ski is bent in an arc on edge, it takes pressure to keep it there.  The "locked" edge doesn't hold it in that arc without body weight.  A ski with no snow under the boot can hold your weight, so that's how much force the ski is pushing back to give you a trampoline feeling.  It's a full time job trying to straighten out all of Jamt's bad physics which I don't have time for, so I'm not going to argue this for a thousand posts, but maybe at some point I'll start a new thread with some video, showing the technique and demonstrating the spring of the ski loaded in particular ways.

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