Getting Rid of Excessive Inner Ski Tip Lead

A snowHead

skimottaret, If you believe that your inside ski and outside ski prescibe two identical radii arcs (as you appear to subscribe to, and is indeed the correct theory) - then the characteristics of the completed arcs will show a wider track at the apex. Kind of like a cresent moon shape. Thinner at the ends, and thicker in the middle.

What rjs said earlier, and what I have found demonstrable time and time again - this shape will occur on the snow (next time you are on a chairlift on a cold crisp morning, look at the shape of the tracks left by good skiers) as an outcome. Without the intent to diverge the feet.

Because we all know what happend in reality, when we try to diverge stiff GS skis that track well, don't we. Toofy Grin

edit: woohoo. 26 pages Laughing

A snowHead

skimottaret, the crescent moon or banana shape of the tracks as they start narrow at the beginning of the carve, widen at the apex, then converge again before starting he opposite carve . . . which makes them look like the inner ski has a larger turn radius than the outer. Lesson 'two' will clarify as soon as I've completed the illustrations Twisted Evil

Well, the person's real but it's just a made up name, see?

Masque, I have a question about your first examples. What happens if you set both skis at 45 degrees, as opposed to one at 45 and one at 46?

Also - I'm not clear yet on the justification on needing to project upwards to measure? After all, aren't we concerned about the tracks left in the snow, rather than the vectors of the forces of the skis that left those tracks?

And I'm still unclear on how you managed to produce arcs with equal spacing AND of the same radius?

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veeeight, How many times do I have to explain to you (and this is getting just a little tiring) If you try to define a three dimensional action using just the trace result of that action in only two dimensions, you have already produced a false result by not using the whole system to calculate cause and effect. Your photo of your test equipment leads me to believe that you aren't even working with a pair of skis to measure the forces involved. On the basis of your arguments so far you are circling the drain in a cul-de-sac at the end of a road with no foundations.

It's obvious you're having problems because you are incapable of visualising that the true radius of the arc is not measured at the snow surface, why should it be?

Ski angles? Just be a little patient and I will release your inner monkey (seriously Blush

)

Anyway, snowHeads is much more fun if you do.

little tiger, Hurtle, Yoda,

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Cambridge dictionary - same Twisted Evil

Then you can post your own questions or snow reports...

Masque, by projecting your radius measurements upwards at right angles to the ski...

..... all you are demonstrating to us is that the inside leg is shorter than the outside leg... Laughing

(which we knew anyway is necessary to ski on an inclined plane)

Every other ski tracks measurements that have been taken in countless studies have measured the tracks on the plane in which they have been created!

Again - we are concerned with the resulting tracks left in the snow - not at which angle they were imprinted.

Plus I (and no doubt the other 2D prophets on here) still have problems with your arcs being indentical and parallel.

After all it is free

beeryletcher, little tiger, you're both correct and wrong depending entirely on the grammatical construction of the sentence. 'with a' and 'with a pair of' are both correct within the context of drawing or tracing the outline of a circle . . .

Pedantry requires a better, if not complete, grasp of the relationships within the grammatical construct . . . try harder . . . and stop distracting me, I'm busy Confused

veeeight,

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Are you really saying to me and the collective world that the radius of an arc drawn on paper will vary and depend on which angle my pencil is held at to the paper??

Shocked

Why don't you do a reverse self-check on your first measurements. Using the same method that you derived 500.35 units and 496.01 units, go to the extremes (90 degrees to the plane, and 0 degrees to the plane) and see if the number spat out make any sense? That would be a sensible self check, would it not?

I am still puzzled by your findings of parallel and identical radii on a 2D plane. Does this not concern you?

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veeeight, OFFS rolling eyes

The arc on the paper is the result of a four dimensional action. A pencil can be held at any angle to the paper to create paths that are identical and if those paths are identical radii they cannot have the same centre-point of rotation, they will be offset, unless of course you are drawing partial arcs of a single circle . . . that's not a pair of skis, that's your hand with a pencil. . . . once again . . . your logic is flawed to the point of farce. When skiing, the interface between the ski, snow, gravity and movement influences the result far more that the scraping of a pencil lead across paper does to the hand holding it.. If you can't find a congruent allegory, don't attempt to use one rolling eyes

Your reverse check takes us to standing still or straight-lining the fall line and while probably creating parallel tracks there is no turn involved so the relevance of your conjecture is valueless.

That's 2 fer naught, you've been sounding stupid for a little while . . . you're now providing tertiary proof. Now go away and have a think about what you're actually trying to provide proof to while I stay busy on related matters.

snow reports

This thread gives the impression of one where a single poster is successfully trolling every other poster. Even if veeeight isn't doing it intentionally, that's effectively what's happening here. 26 pages of time and effort has been spent arguing with someone who demonstrably here and previously is not going to get it. Even if he does.

You know it makes sense.

Are we any closer to a conclusion here? Or perhaps the snow, fresh air and mountains are simply enough?

Otherwise you'll just go on seeing the one name:

SMALLZOOKEEPER, what I want to know is, when skiing powder, what happens if I diverge my inner ski at the start of a turn? Toofy Grin

A snowHead

A snowHead

Well, the person's real but it's just a made up name, see?

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My god, I haven't been following this, but 26 pages!!!! Shocked

It looks like the original question has strayed and now we are into semantics and geometry, that's got to be par for the course for BZK Laughing

So are you lot taking bets for how much longer this will last, is there a prize for guessing the final thread length? - I'm going for 32 pages!!

Anyway, snowHeads is much more fun if you do.

I'd put money on ski tracks almost never forming a true arc of a circle anyway, so its all a bit moot Twisted Evil

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rich, this has been covered somewhere in the previous 25 pages. For any given point on an arbitrary curve, the "radius" becomes the distance to the centre of curvature. "Radius" is a convenient shorthand for that concept.

Then you can post your own questions or snow reports...

Probably been said before - but I suspect there is one special case (other than straight-lining) where the tracks will be parallel and identical viewed perpendicularly above the individual part of the track at which you are looking - but not if you look at the tracks as a whole from any single point. The case would be when you are on banked surface (like Berms on a MTB) where your speed and the track is aligned so that there is no lateral force needed to maintain your line and your centre of mass remains directly perpendicularly above the centre line between the skis at all times.

But that actually isn't really turning at all.

After all it is free

Here beginneth the SECOND lesson -or- Why your inner monkey needs bananas

Ever seen a baby stick its big toe in its mouth, and as a passing thought wonder if your girlfriend can do the same? . . that just means you're a sick puppy and should be concentrating on why this relates to skiing. . .

When out ancestors finally got tired of falling out of their trees and began spending most of their time wandering around and getting lost in tall grass, their need to stand up and see their surroundings was quite paramount and eventually part of our evolutionary development as the pelvis and hip-joints of those who could stand tall enough to see, run fast enough to catch, or alternatively avoid, the fur covered, be-fanged beasts that can hurt so much yet taste so good . . . survived and out-bred those that turned out to be just bait. Thus we evolved to be able to walk and run very efficiently on two legs.

But God's never let us forget that at one time we shared our arboreal cousin's ability above ground and while they can't rotate their hips forward to walk upright without waddling, we can still splay our knees and climb a tree.

That's not the end of it though, as it turns out, bipedal efficiency requires us to be able to adjust our lateral vectors through our contact point with the ground, i.e. It doesn't matter how fast you can run in one direction, if you can't turn, you're going to get eaten. And to turn efficiently without stressing or breaking your hip joint it needs to be able to rotate just like our little hairy brethren. . . which ultimately leads us to why our inner monkey needs bananas. . .

The starting point:

Stand crossways in a doorway with your back against the frame and so that your parallel feet straddle the threshold at hip width apart. Actually, this is a bit of a measurement issue as most people think that 'hip width' is at the widest part of their ass. . . it's not, its at the hip joint interface itself, which is two to three inches inside that, so when you stand there as an adult male your feet will be about 13 inches from centre to centre-line, you ladies can add an inch or three. So far so good as, if you sag your knees, you will be emulating your position as in a straight schuss down a very gentle slope. If you're in neutral balance you should find that your weight is passing through your feet just in front of your ankle, mid-way between your heels and the balls of your feet. The size of your gut and ass will have an small influence on this, as will your gender, but it's not big enough to concern us at this level of discussion.

Now step sideways without any deliberate effort to control your foot position, it doesn't matter which side. Now look at your feet, are they still parallel and where do you feel the most pressure in the sole of your feet? The vast majority of us will have a slight to moderate turn-out and the wider the side-step, the more pronounced the angle, at the same time you'll find that your foot pressure has moved closer to the balls of your feet. There's nothing unusual about this, it's evolution's way of ensuring your best possibility of survival.

Come back to your stating point with your feet apart and your back against the door frame and take a step the same width laterally and this time, forward by the same amount . . . and hold.

What do you feel? We're not wearing ski boots so we're free to feel the forces induced directly. As before we will have a divergent foot angle and at the same time we'll be feeling increased pressure in the big-toe side ball of the rear foot and across all the toes of the lead foot. Already we have changed the force dynamics of the feet. Whist we are in balance, our feet are performing different tasks to achieve this.

Whilst you're in this stepped position, support yourself of the opposite door frame and sag your knees while pushing your hips forward, what do you feel now? Look down and your lead foot is now rolling over onto its outer edge and you're supporting more of your weight through its toes while your back foot has become more relaxed and may even be flat to the floor. This experiment does not include the centripetal force vector that a carved turn puts into and through your body, increasing the load into your lower or lead leg, it does show that at any point in a turn, your feet and thus your skis are performing as independent parts of a larger machine.

Now, before we move on, there's one more little demonstration. Go back to your upright , balanced, feet parallel apart stance and raise a knee till your thigh is horizontal. Grab hold of the opposite door frame if you need and look at your raised foot . . . I'll bet you a weeks EOSB bar tab that not only are your toes pointing down but also that your foot is turned inward . . . even if you're attempting to raise your knee directly in front of you.

The feet of your inner monkey still want to climb a tree

You're Bananas (Lynne Truss, forgive me)

One of the things we can all agree on is that if we point our skis down a hill it's fairly easy to keep them close together and in what can easily be termed as parallel. It's when we start to turn that things become a little more complex.

Can we accept that for most of us, turn initiation begins with slightly pressuring one big toe whilst gently pushing forward the opposite foot?

OK, we're in the early part of a carve, we're beginning to feel a lateral centripetal force to which we balance by rolling onto our edges . . . let's keep it simple for the moment and just talk about inclination to the slope, ignoring angulation and concurrent rotational and shear force insertions . . .

sorry, nerd induced brainfart . . .

So, we begin to have an acute angle, off the perpendicular, to the slope and since we don't have telescopic legs we have to absorb the increasing angle by another method . . . we lift our foot . . . but since out boots are just a little bit stiff and we can't flex our ankle there's only one thing we can do . . . we push them forward as we are forced by the mechanical constraints of our footwear and upward in relation to our downhill foot.

Interestingly, as the knee raises, your boot encased foot rises in an exponential curve, but to simplify, that just means that the higher the foot is raised, lesser the forward distance from the other. Essentially here is a limit to how much 'tip-lead' you will naturally incur when carving. There's an easy way to emulate this . . . stand next to a coffee table, in yer ski boots if you want to be castrated by your Mum, significant other or the furniture showroom salesman and lift your foot onto it. Once your knee passes the horizontal (in relation to the vertical plane of your body only) your foot is now coming back toward your body

Well, we're in our carving turn now and yet to settle into V8's "park and ride", we're turning across the fall line and having to counteract the down-slope inertial force, we incline further into the slope and by mechanical default the vertical separation of our skis increases . . . Again we're in an exponential curve, this time it's, for want of a better description, pressure through your feet. The higher your speed and/or the tighter your carve, the more acute the angle your ski edge needs to insert into the sliding surface and the further over you go the less you can apply inner ski pressure. Again this is all to do with balancing vector forces and that as you get faster at a more acute angle to the surface, it's more difficult to angulate . . . back in nerd mode . . . Essentially, the more you lean into the hill the greater your 'vertical' ski separation needs to be.

But now we've decided that we've turned across the pitch far enough and we're going to turn down the slope into the fall-line. So, a little more force into the uphill ski raises our body away from the stable carving incline and if we're in control, into an opposite carve. During the transition our skis draw together and we pass through a position where our feet and skis are back to being close and actually parallel. The tracks behind us are a banana shape simply because at the root of our ability to ski, we're still monkeys.

Now back to the maths:

But before we go there, we need to have a short sidebar on skis. Hands up those of you that think if you grab a ski at its tip and its tail and squeeze, you're going to get a nice simple, symmetrical partial arc of a circle? Good grief, even the gnawed from a single lump of wood by semi house-trained beavers and then strapped to your feet with reindeer entrails skis have a compound curvature. i.e. They bend in a different way dependent on where you put force into them, as the photo of V8's Heath Robinson pastiche so succinctly illustrates. So what I've done in the following is use a generic ski with a softer tip and a stiffer tail. This should emulate and illustrate the overwhelming class of 'punter' ski that we all know and love.
Our 'punter' is Joe snowHead, Mr. or Mrs. advancing intermediate . .

Fig.1 Simply illustrates that as we stand still over our skis, they spread our gravitational load 'A' over the length of the ski. The whole ski(s) is under load but as it's able to flex, that load is distributed the length but will be concentrated under the centre of that load.

Fig.2 Brings us to the position of Joe at mid-carve. I'm attempting to use a non-aggressive situation as the nuance of a slow gentle carve and the brutality of a high speed GS turn are both equally difficult to define or even justify within the context of this thread about 'excessive tip-lead'. The ski is being acted upon by three primary forces. Joe's mass and the two main points of contact with the snow that're resisting it

and Fig.3 has Joe snowHead sliding along in a balanced carve. Tip and tail are engaged and the rest of the ski is flexing within the side-cut to create the carve. That's pretty much it, Joe's lard + centripetal load is acting through the engaged lead and trailing edges to bend the ski. A chord drawn from tip and tail will give us a basic or mean curvature to define a carve circumference and its radius.

All well and good if you're riding a monoski . . . but he's not, Joe's got a foot in two camps and each has to share the load.

Fig.4

has Joe taking the easy route and simply stepping sideways up he hill to stay balanced . . well that works . . . until he realises that he has neither telescopic legs nor a ski boot with a flex value of 0, Zero, Nada, putting us looking at Joe in Fig.5

This is beginning to work, Joe's got two skis, both equally weighted, and both describing the same circumference arc . . . sweet! Till the arcs cross and Joe goes teat over apex.

- - - -

There's a fundamental problem here, It's called "tip lead". It doesn't matter how great or small it is, as long as it exists within our skiing and both skis are describing the same partial arc of circumference . . . the skis are going to cross and all of us, including Joe, are going to eat snow.

- - - -

Finally, we arrive at Joe snowHead in a stable, controllable carve, skis staying inside paths that don't cross and able to complete a turn into the inception of the next.
He's drawn his uphill ski back until shin pressure on his boot has pressured the tip of that ski more than he tail, simultaneously his inner monkey has rolled the ski over to a much more acute angle . . All before he doesn't realise that he's reduced the load or relaxed to the side/torsional loading on his downhill ski, lengthening the turn.

All this boils down to Joe snowHead being able to carve clean arcs keeping his or her skis from diverging or crossing.

veeeight, not only is your hypothesis so flawed as to be less than a joke, you are also hurting the profession of ski instructing

Shame on you.

Shame on me for being drawn into your ignorance.

*Ski* the Net with snowHeads

Masque, I do admire the work you have put in. I really thought we were in for something groundbreaking!!

On the subject of stance, I am sure the manufacturers of abducted ski boots will be having a giggle even now.

On the subject of your first lesson, the points I raised are still as valid and still need clarifying as the numbers just don't stack up.

On the subject of the second lesson, all you have proved is that skis do ski identical arcs which will on paper cross over - something that was said wayyyyy back on this thread. As to why they don't in real life - surely even you can work this out?! Laughing

There are so many myths and mistakes on your assumption oh how carving works in your second lesson I can't even decide on where to start!

You are not telling me anything new regarding banana shaped arcs, have you been awake for the last 3 pages where I have specifically stated that identical radii will produce banana or crescent shaped arcs due to the fact that the inside and outside ski prescribe the same radii?! And you have just shown us that this occurs as an outcome!

You should really publish this for the benefit of all the coaches out there who are apparently bananas!

Once again - you do not need to diverge your feet/boots/skis deliberately in order to accommodate clean arcs in the snow! This has been proven time and time again repeatedly in the snow!

Are we really any further forward? Are you suggesting that because the paths cross, we therefore have to have the inner ski in a tighter radius, and therefore have to diverge our skis at the start of the turn?

I mean, "roll the uphill ski over to a more acute angle" - are you really listening to yourself type this?!!?!

But hey - well done on your persistance, and good luck with diverging your skis deliberately!

snowHeads are a friendly bunch.

snow reports

veeeight, you're a joke and divergence is perfectly natural and if your mind had more than marbles in it you'll see that not only is the lead or uphill ski further along the turn but has a different shape and set at a different angle to the snow. All you have done in all of these pages is to prove that you can build a machine to bend a ski . . . and Oh look mummy, I can do it again in exactly the same way. Even your wee robot shows the ski in a compound curve.

If you've spent all your efforts to create an artificial justification for a flawed idea . . then all you deserve is our pity. All I've done is use a basic knowledge of the human body and simple geometry to be included in the process of carving a turn. Your stated intent to exclude them is what makes you a joke. Your thinking and your experiment is at the skiing level of 'banging the rocks together' . . and you've yet to realise that you need to move your thumbs out of the way.

As I said before. the fulfilment of low expectations . . . makes me proud and happy to be a boarder, at least your theory works for me. rolling eyes

Masque, well done on bringing the discussion towards Biomechanics and away from pure geometry.

veeeight, all i can assume you are doing now is being provocotive for the sake of it. I shouldnt bite but as each of your points have been shot down in flames you haved shifted your "you against the world" arguements to different areas. Your habit of when you get stuck then dangle out dual statements whilst implying that have "the" answer is most annoying and adds nothing to the debate.

For a while we had you argueing that turns can be identical and parallel, then identical RR turns with identical shin angles prescribing same radii, then during RR turns convergent/divergent tracks (moons) are normal, to the inner radius must be greater than outer, to intent vs outcome, and now your latest holy grail appears to be that Knucklehead coaches/instructors are foolishly patterning active/intentional diverging skis during training. Who ever said that?

You know it makes sense.

You find me a current FIS or K1/K2 coach that actively trains people to diverge their feet/boots/skis at the start of the turn. rolling eyes

You guys constantly talk about cod maths.... there is a prime example of this on this page!

Otherwise you'll just go on seeing the one name:

veeeight, Nobody, I agree with you.. (on this at least wink

) I havent heard/seen any of the senior coaches at our place ever do any drills or training for that, nor have we done much rotary but these things occure when skiing hard, doesnt it?

but as per my last post who here has said that we should be actively patterning divergence? you seem to be looking for arguements when none is presented.

A snowHead

veeeight, the wheel's turning but from the smell, the hamster's dead rolling eyes

Tip-lead, ski diversion and differing edging angles during a carved turn are a result of the human body being built the way it is and the equipment it is wearing. The deliberate action of the skier is to control these and we use the interface of the ski with the snow to stay in dynamic balance by changing edge angles, torsional leverage (angulation) and modifying the forces entering the ski along both its yaw and longitudinal axis. All that you appear to to be researching is the track left by a skier who is acting in 4 dimensions while interfacing with the snow on at least 7 planes of measurement . . . and you're using just the one factor in one plane of a complex machine to extrapolate its overall performance? It's not just bad maths it's bad science.

I'd be less willing to call you a fool if you had installed a series of strain gauges along the sides of a pair of skis and sent a good skied down a well bashed smooth slope. That would at least give you comparative data to put against video analysis.

What makes your input in this thread so laughable is your thinking that the plane of the slope is a valid single reference. Simple geometry tells us that it doesn't matter. The centre of a skier's turn rotation is the point around which the skier's mass rotates and that's not on the slope surface, though it does have a mechanical relationship with the radii of the two skis. You can project a ski's track radius, which is not the same as a ski's turn radius, up a slope to infinity and if all you do is step that up the hill to make another track, the marks on the infinite hill will stay the same distance apart.

I'm genuinely appalled by the paucity of thought that seems to have gone into your experimental procedure. This is my analogy of what you appear to be doing.

You find a dog turd on the sidewalk . . it's a fresh dog turd . . . and from its circumference you can surmise the approximate width of the dog's asshole . . . add a bit of sniffing and squeezing, you might even get an idea of the dog's diet. What it doesn't tell you is the breed of the dog, the size of the dog, the age of the dog, the pressure of its evacuation, where it lives, or if it was on a leash. But you have a measured, quantifiable amount of dog turd . . . from which you extrapolate that all the next dog turds that look, smell and feel similar . . . are from the same dog rolling eyes

That, from your explanation, is the level that your research is at. That is why we are perceiving you as a joke or a troll, So far you have demonstrated misuse of basic geometry and clearly stated an intent to remove the human variable from a ski's interaction with the snow surface. The next time you come here it had better be to clearly explain how any of your work relates to skiing as a dynamic human sport and within the context of this thread about 'tip lead'

The floor's yours . . . you can shine it or soil it, it's now down to you, I no longer give a fcuk.

A snowHead

skimottaret, exactly. Tacitly, veeeight has come a long way from his insistence that tracks can and should be both parallel and identical: he just throws out bluster, rhetorical questions and delphic hints at divine knowledge to avoid admitting that he was wrong or that anyone else was right.

Well, the person's real but it's just a made up name, see?

You need to Login to know who's really who.

Anyway, snowHeads is much more fun if you do.

skimottaret, are you sure you wouldn't prefer me to add your knowledge of dog poop? I can tell you why you don't see white ones any more . . . Confused

Here's a simple experiment. Put on your ski boots and perch on the front edge of an office swivel chair. Raise the chair to its highest position where your legs are in a soft angle carve position, your feet are flat to the floor and hip distance apart with your knees over the centre of your feet just in front of your ankle.

NOW! Rotate the chair whilst keeping your torso facing forward . . . i.e. facing down the hill . . . look at your feet to see both divergence and a considerable edge angle difference.

This exercise, exaggerates the bio-mechanics involved as there are a lot of balancing and counter-active elements in the carving process that modify this result. Not the least of which is that the more forward separation you have with the inner ski further along the turn track (the visual divergence we see in carving skis that is a mechanical function of two skis separated with tip-lead), the slope geometry automatically reduces the angle of edge insertion of the lead ski into the slope surface (think about it).

Before I go any further with this, I do have to express some personal reservations. The first is that I'm a boarder and have only, as of the '08 EOSB, 29 days on skis. I don't even think I'm qualified to judge the standard of my own skiing, that has to be for others . . . a small number of whom have seen my finely honed ass-planting technique in black bumps . . . But, I do have other experience to bring to this discussion. Many moons ago I was a regional level qualified trampoline coach and district level gymnast trainer and despite the onset of elderly prostate driven night-time ablutions, a fair chunk of physiological knowledge still manages to surface when prodded with the sharp stick of someone's wilful ignorance. Also, My degree was art and not maths so I'm referencing the dim history of a barely scraped Maths A'level. This is what so appals me about some of the argument presented in this thread, If I with my woeful skill and abstract knowledge can observe, de-construct and define part of the skiing process, just what the hell has gone wrong with the instructor training that has left a group of ostensibly highly qualified people constructing experiments that only demonstrate their lack of understanding of the mechanics of the sport they teach?

There is a 'window of opportunity' in a carved turn where we can be driving round on our tails with our ass dragging . . . or with wildly separated legs . . . or with tight buns and ankles locked. . . or with screaming muscles in one leg and the ski on the edge of delamination. They are all the result of the pilot's skill, strength, mental attitude and first of all, his or her bio-mechanical control . . or lack of. Twisted Evil

skimottaret, I'm tied up with other matters for the next few days but I will take the time to sit and try to separate and quantify all the forces I experience while carving. I warn you, I do think that there's a hell of a lot going on in carving a turn and while it's easy to say that it's just a mental switch between carving and skidding . . . it's a long reach to the switch for many and if your instruction doesn't understand the steps to the rungs on the ladder . . . . Confused

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Masque, The position that you end up in at the end of your experiment is an example of too much inner ski tip lead. A race coach would work to change this movement pattern.

Assuming that your experimental chair has castors, try another experiment. Return to your starting position then slide it sideways by 30cm. This is much closer to what happens during a carved race turn. The feet do have to diverge, or else they will bump together, but the sensation is of them staying a similar width apart.

Then you can post your own questions or snow reports...

rjs, absolutely agree, skimottaret was asking about different ski insertion angles into the slope, the same thing occurs in your example. What is probably even more realistic is to combine both a moderate lateral movement of the chair (angulation) with some twist of the torso away from the direction of movement. In all three examples we illustrate a similar result with our toes diverging and feet at different angles to the surface. I was using this to illustrate why the mechanical construction of our bodies is a significant part of the skiing process and it's how we deliberately use our natural morphology in the interaction of the ski and slope that allows us to draw our feet closer together, reducing tip lead and insertion angle and at the same time move the force vector point into the inner ski forward, loading the tip, changing the curvature of the ski and reducing its turn radius. The counterbalance to this is that if you increase the load in one ski, you will decrease it in the other . . . you have a fixed amount of mass + whatever centripetal force you are generating . . . and if you reduce the load in your lower ski you will also reduce its curvature, lengthening the turn.

As we see so often in photographs and video of racing skiers in an extreme carve, they want the tightest carved turn they can achieve. You can only do this by loading the downhill ski to the point where the uphill ski is barely touching the surface. Often you see that the large foot separation required to get your centre of mass low enough to get the maximum possible force below the surface point of contact of the ski edge (that's really going to stir the juice between v8's ears), has the inside foot raised so far as to force the trailing edge away from the slope, letting the tip dance around the turn with only the skiers strength and training keeping inside the lower ski (not always as some epic yard sales demonstrate).

After all it is free

Masque, I am pressing you on this as i think, and you point out, that there is a huge lack of understanding on Body mechanics as it relates to skiing. It isnt even mentioned in ski instructor training until the "advanced" levels and the only written info i could find was primarily related to boot fitting and alignment as opposed to what the body can and cant due when trying to make turns. I tried to get some threads going on this subject but there was little interest and i would be keen to hear from our resident physicians and physical trainers on this subject. As they arent in the house that leaves the trampoline coaches wink

I am much more interested in understanding how skiing movements are dictated by biomechanical limitations as opposed to arguing geometry or defining the forces in a turn, that has been done to death and is available in texts. keep your gymnasts brain tumbling on those issues Toofy Grin

I agree with rjs, your example would produce an old skool overly countered position with excessive tip lead, which i had to mention as the point of this thread 20 pages ago has been long lost.... wink

Not done the maths, but to me both of your examples show that on an incline when the inner knee is substantially raised inner tip lead naturally occurs which will generate a higher edge angle on the inner ski in relation to the slope as compared to the outer ski. With a higher edge angle the ski will track a tighter radius even if is isnt pressured. Do others agree?

Damn, more stuff to have to carry in my backpack. Protractor, set square and calculater! Smile

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chris, welcome to geekdom

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Getting Rid of Excessive Inner Ski Tip Lead

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