 Poster: A snowHead
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| laundryman wrote: |
| veeeight wrote: |
| However if you believe that the two ski arcs start off life as identical arcs of the same radius - then the need to beleive in diverging skis go away. |
The utter incoherence of this sentence is symptomatic of your hazy, even dim, grasp of logic and geometry. Stick to the day job - just don't use cod geometry and mechanics with customers who are better qualified in those fields. |
I take it your misguided belief is that the inner ski prescribes a smaller radius then?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| FastMan wrote: |
| This is a big part of the equation. As legs tip to higher edge angles, feet must separate to keep the legs from hitting together. How that separation is accomplished is at the heart of this topic. There are two basic ways. You can drag the inside ski sideways as you tip into the turn and flex the inside leg, or you can diverge the skis at the start of the turn and let the inside ski track the inside foot into a larger separation by apex. BigE's moon example. |
Consider this, and try it for yourself. Set off down a moderate slope, and do nothing other than edge both skis by the same amount at the same time. Preferably park and ride. Zero rotary/pivot. Examine the resulting ski tracks. You will find that they will look exactly like BigE's moon example, without you doing anything other than tipping/edging.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| veeeight wrote: |
| laundryman wrote: |
| veeeight wrote: |
| However if you believe that the two ski arcs start off life as identical arcs of the same radius - then the need to beleive in diverging skis go away. |
The utter incoherence of this sentence is symptomatic of your hazy, even dim, grasp of logic and geometry. Stick to the day job - just don't use cod geometry and mechanics with customers who are better qualified in those fields. |
I take it your misguided belief is that the inner ski prescribes a smaller radius then? |
No, the fact is that there is divergence and convergence. The problem for your theory is that the basic laws governing time and space in our dimension would have to be changed for you to be right.
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You need to Login to know who's really who.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Masque that is an amazing effort for this late at night - or early in the morning - I'm not sure what time zone you're in.
| Masque wrote: |
| I'm pretty certain that we've all agreed that because the uphill ski is leading the turn it has a steeper angle of inflection to the snow. |
I don't remember agreeing to that  You've lost me - please can you explain to this dumb, non-university-educated ex-ski-racer.
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You'll need to Register first of course.
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| Masque wrote: |
| veeeight, are you capable of discerning a 1º difference between your ski's slope interface? |
Now that I do know the answer to: yes, because he says he can roll his ankles at least that far in his spongy skiboots! 
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'Martin Bell, If we don't look at the 'balls to the wall' pics of your colleagues powering down the hill on alternate legs you'll see that when the uphill leg gets bent more than the downhill and the foot pushes through along the path of the turn to create 'tip lead' it rolls the lead foot over at a slightly . . . anything up to 6 or 7 degrees . . . increased angle of attack depending on your physiology. Perch a but cheek on a chair and place your bare feet on the floor in the positions forced on them as you adopt the leg shape of a carved turn. A swivel chair makes this easy. If you look at the pics of people in a more equally pressured carve you'll see the inner ski lain over at a steeper angle than the outer. It does look to have a common relationship to tip-lead as the greater the lead the greater the angle difference.
We'll be moving on in other instalments to address the many other factors that shape and define the relationship of two tracks in the snow but I thought I'd start with getting mashed veg's head off the snow surface and start realising that a sliding body's measurements need to be taken where they exist above the surface and that the two tracks in the snow are a very small part of defining skiing ability but if you are going to use them then you'd better not pull a string of geometric daisies out of your butt to give your words gravitas.
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| veeeight wrote: |
| I take it your misguided belief is that the inner ski prescribes a smaller radius then? |
Ignoring the gratuitous "misguided", in the special case of parallel tracks, obviously, throughout the turn. In the special case of identical tracks, obviously not. In the general (that is, overwhelmingly common) case, at times yes and at times no. As the skis diverge from the transition, until their angle of divergence is at a maximum, yes. From then, through a parallel position at the apex to the point at which their angle of convergence is a maximum, no. For the remainder of the turn, as the skis move back to a parallel position, yes.
BTW, "prescribe" is what doctors do. The word you're looking for is "describe", though a plain word like "trace" would do. That's the sort of thing that happens when you half remember concepts you only half understood in the first place.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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laundryman,
| Quote: |
BTW, "prescribe" is what doctors do. The word you're looking for is "describe", though a plain word like "trace" would do
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Oh, thank God. I can't tell you how long I've been wanting to post that.
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After a few hours of Apres ski my eyeballs aren't parrallel, is this divergence or convergence?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| veeeight wrote: |
| FastMan wrote: |
| This is a big part of the equation. As legs tip to higher edge angles, feet must separate to keep the legs from hitting together. How that separation is accomplished is at the heart of this topic. There are two basic ways. You can drag the inside ski sideways as you tip into the turn and flex the inside leg, or you can diverge the skis at the start of the turn and let the inside ski track the inside foot into a larger separation by apex. BigE's moon example. |
Consider this, and try it for yourself. Set off down a moderate slope, and do nothing other than edge both skis by the same amount at the same time. Preferably park and ride. Zero rotary/pivot. Examine the resulting ski tracks. You will find that they will look exactly like BigE's moon example, without you doing anything other than tipping/edging. |
So, what do you speculate causes the skis finishing one turn/moon on converging inside/outside ski tracks (that's what moons do), to suddenly debark on diverging tracks for the start of the next turn/moon (that's what moons do).
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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alan empty, so do I What's that saying - never argue with a fool - he'll drag you down to his level and beat you with experience - or something along those lines?
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| veeeight wrote: |
| FastMan wrote: |
| This is a big part of the equation. As legs tip to higher edge angles, feet must separate to keep the legs from hitting together. How that separation is accomplished is at the heart of this topic. There are two basic ways. You can drag the inside ski sideways as you tip into the turn and flex the inside leg, or you can diverge the skis at the start of the turn and let the inside ski track the inside foot into a larger separation by apex. BigE's moon example. |
Consider this, and try it for yourself. Set off down a moderate slope, and do nothing other than edge both skis by the same amount at the same time. Preferably park and ride. Zero rotary/pivot. Examine the resulting ski tracks. You will find that they will look exactly like BigE's moon example, without you doing anything other than tipping/edging. |
So, what do you speculate causes the skis finishing one turn/moon on converging inside/outside ski tracks (that's what moons do), to suddenly debark on diverging tracks for the start of the next turn/moon (that's what moons do).
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You know it makes sense.
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| FastMan wrote: |
| So, what do you speculate causes the skis finishing one turn/moon on converging inside/outside ski tracks (that's what moons do), to suddenly debark on diverging tracks for the start of the next turn/moon (that's what moons do). |
Surely, even you  , know that you can influence a skis direction and turn radius without the need to diverge your feet?
Or let me ask you - can you think of a way(s) to make a ski change course without the need to turn/twist the feet?
Last edited by You know it makes sense. on Fri 14-11-08 11:21; edited 1 time in total
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Poster: A snowHead
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| Quote: |
The uphill ski will always turn tighter than the lower as long as it is measured correctly.
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Well there we go, turning more tightly means a tighter turn radius. How do you get the inner/uphill ski to turn more tightly?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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veeeight, if you are going to cite an example from Epic you should copy it here so people can relate to what you are talking about.
"BigE's moon example" makes about as much sense as most of your other attempts to explain your position...
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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skimottaret, we passed that point where people are actually interested loooooong ago, people are far too entrenched in their views and have resorted to picking me up on spelling and grammar. But I do take your point.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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veeeight, there's a bunch of guys who've helped each other to increase their mutual understanding ... and there's you.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Well I have long ago lost interest in the maths... sadly as it started out somewhat interesting.... I continue to watch the thread as i would do if stuck on a motorway and the fireservice is cutting a victim out of a car wreck...
Your crash was mainly down to not paying attention but there is some bad driving involved, but you are almost out of the wreckage... 
I take a pragmatic engineers view on this not a Phd's arguing a proof. When you take away the "pure" case of a "perfect" set of curves made when skiing with your joints and skis "exactly" in the right position all the discrepancies between the "2D" that you refer to are easily explained. GrahmanN worked out a few degrees of leg angle makes this possible, Masque a few mm's etc. let alone dozens of other examples of slight torque or slight shovel loading, scissoring, etc. that can EASILY explain how a skilled skier can make same radius carved turns.
The odd thing to me is that you still cling to the notion that you and your racers can hold perfect body positions and that nothing changes during the these perfect turns you can make while scribing your "perfect" tracks on the surface.
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You'll need to Register first of course.
You'll need to Register first of course.
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laundryman, a bunch of guys with pack mentality can/will eventually talk themselves around to anything they want to believe in, by being selective in what they absorb.
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| skimottaret wrote: |
| The odd thing to me is that you still cling to the notion that you and your racers can hold perfect body positions and that nothing changes during the these perfect turns you can make while scribing your "perfect" tracks on the surface. |
Because, as rjs said before, it would be a gross mistake to train this route of accepting less - I have done and seen time and time again, in our training regimes, repeatable clean arcs, without the need to fudge, or pivot, all at reasonably high edge angles.
It would be a poor get out clause and thinking to start accepting that the inner ski has to prescribe a smaller radius for example, in order to justify ski divergence.
Do you believe - holding both feet/boots - straight (zero divergence/convergence) - could result in ski tracks that widen and narrow? I think that this is the crux of the issue - on how widening/narrowing ski tracks are produced without actually any toe-in or toe-out at the boot.
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veeeight, yep, we've talked ourselves around to believing that a ski instructor hasn't overturned two millennia of received wisdom in geometry. Not terribly hard, but we've had some interesting excursions into (for example) proof from first principles and the analysis of turns of the world's top skiers not breaking the known laws of geometry. A nice synthesis of theory and practice. Thanks for setting us on the journey; too bad you couldn't come along.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| Quote: |
I have done and seen time and time again, in our training regimes, repeatable clean arcs, without the need to fudge, or pivot, all at reasonably high edge angles.
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and your "Mark I human eyeball" measuring device is sensitive enough to determine leg angles to 1 degree when your athletes ski past while making these "repeatable" turns?
ps i have backed your assertion that the inner ski does not neccesarily need to transcribe a smaller rad but where we differ is that i think the skier is compensating for (but not breaking) the laws of motion by making subtle (and generally) undectable changes while attempting to make these theoretically perfect arcs.
Lets go back to my post showing an instrumented National Team level skier making GS turns that arent particularily agressive and see how much his joints move about to maintain decent arcs. It brings into context my assertion about small movements making all the difference.
http://uk.youtube.com/v/Z9JLJ0hndmw&feature=user
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skimottaret, when you've played with, and been a party to countless experiments on snow, with equipment like this that provides repeatability with the human variables removed, you kinda get to know which is the correct answer and which are fools chasing false prophets.
As a ski instructor, surely you see and know what happens if you try to carve clean arcs with deliberately diverging skis?
I've said previously - rjs is so close to the nail on the head with regard to intent and outcome of widening/narrowing ski tracks.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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| veeeight wrote: |
| FastMan wrote: |
| So, what do you speculate causes the skis finishing one turn/moon on converging inside/outside ski tracks (that's what moons do), to suddenly debark on diverging tracks for the start of the next turn/moon (that's what moons do). |
Surely, even you , know that you can influence a skis direction and turn radius without the need to diverge your feet?
Or let me ask you - can you think of a way(s) to make a ski change course without the need to turn/twist the feet? |
Of course, there are many ways,,, but that's not the point of my question. Skis that never leave a parallel orientation to each other can not get wider separation from transition to apex, then back to narrower again from apex to next transition (your moon track shape), via means of 2 clean carved tracks. Yes, you can get there with parallel skis, but it involves dragging the inside ski laterally to produce the greater separation.
Personally, as a coach, I don't fret to much over which method a person uses to gain additional apex separation, as long as the business ski (the outside ski) is doing what's it's suppose to do. I think all people are doing here are trying to explore and understand the options.
Same with the smaller inside ski radius need thing. It's pretty obvious to most that in carving a half circle with skis parallel at all times, the outside ski has produced a larger radius half circle than the inside ski. For some who have come to understand that, it's an interesting discussion exploring ways of making that radius difference happen. There are a couple options.
Hint, think about this;
- Did Stenmark carve turns?
- Did he use knee angulation, and ski A-framed?
- Did he at times while doing this ski with his skis parallel?
- How did he accomplish this maintaining parallel skis feat?
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You know it makes sense.
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cathy, 
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Poster: A snowHead
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Posters, Poseurs, Punters and Gurus.
We are approaching the 1,000th reply, a snowhead First and a New World Record (yes I have check with Dr. Ross McGwirter)
Who will dare to make that record-breaking post, to set history? Who amongst us has the Gravitas, the Knowledge, The Bombast and the sheer Nerve to step up to the mark and make the Defintive and Deciding Post on ..er.. what was it again? oh yeah, How Much to Tip when Skiing.
All of  dom awaits, time stands still as the world watches....
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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beeryletcher, the ice is thin on Gorky Park lake for the time of year
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You need to Login to know who's really who.
You need to Login to know who's really who.
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beeryletcher,
de·scribe (d-skrb)
tr.v. de·scribed, de·scrib·ing, de·scribes
1. To give an account of in speech or writing.
2. To convey an idea or impression of; characterize: She described her childhood as a time of wonder and discovery.
3. To represent pictorially; depict: Goya's etchings describe the horrors of war in grotesque detail.
4. To trace the form or outline of: describe a circle with a compass.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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You'll need to Register first of course.
You'll need to Register first of course.
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trace 1 (trs)
n.
1.
a. A visible mark, such as a footprint, made or left by the passage of a person, animal, or thing.
b. Evidence or an indication of the former presence or existence of something; a vestige.
2. A barely perceivable indication; a touch: spoke with a trace of sarcasm.
3.
a. An extremely small amount.
b. A constituent, such as a chemical compound or element, present in quantities less than a standard limit.
4. A path or trail that has been beaten out by the passage of animals or people.
5. A way or route followed.
6. A line drawn by a recording instrument, such as a cardiograph.
7. Mathematics
a. The point at which a line, or the curve in which a surface, intersects a coordinate plane.
b. The sum of the elements of the principal diagonal of a matrix.
8. An engram.
v. traced, trac·ing, trac·es
v.tr.
1. To follow the course or trail of: trace a wounded deer; tracing missing persons.
2. To ascertain the successive stages in the development or progress of: tracing the life cycle of an insect; trace the history of a family.
3. To locate or discover by searching or researching evidence: trace the cause of a disease.
4. To draw (a line or figure); sketch; delineate.
5. To form (letters) with special concentration or care.
6.
a. To copy by following lines seen through a sheet of transparent paper.
b. To follow closely (a prescribed pattern): The skater traced a figure eight.
7.
a. To imprint (a design) by pressure with an instrument on a superimposed pattern.
b. To make a design or series of markings on (a surface) by such pressure on a pattern.
8. To record (a variable), as on a graph.
v.intr.
1. To make one's way along a trail or course: traced through the files.
2. To have origins; be traceable: linguistic features that trace to West Africa.
adj.
Occurring in extremely small amounts or in quantities less than a standard limit.
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At the end of the day all I'm concerned about is producing the best skiers.
I and countless others on the hill know that that does not come about by getting them to deliberately diverge their feet, and in turn, their skis. I suggest the armchair experts get out of their sofas to actually try this on the hill with some good skis to see what happens. This is truly a case of trying to reverse engineer real life to a so misguided theory.
No one has yet produced a photo montage video from amongst thousands of pictures on the internet of two skis in an arc, where the inner ski is bent more than the outer ski. It just doesn't happen. You do not ski with a tighter inside ski. As a current WC athlete once said during a clinic - "you can't do that". End of.
As for producing a moon shaped arcs - we did this on the hill again yesterday. One turn. Edge the ski, no pivot/rotary. Voila. widening tracks. How many of you have actually tried this on snow, before coming onto here to spout off? Even better - try posting your theory on diverging skis on Harbs forum. Should be good for a giggle!
As usual with these sorts of discussions, time will show whos on the correct track and who isn't. I know where my money is.
You pays your money, and you takes your choice. It's simple. Listen to the false prophets of 2D diverging skis, and ski as you wish!
Last edited by After all it is free  on Sat 15-11-08 11:20; edited 1 time in total
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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veeeight, you keep referring to this moon shape arc theory can you explain further, or can copy some stuff from the other place as i dont get what you are trying to say.
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veeeight, define "bend" . . .
And if you're a little patient I will complete lesson two and gift you a little reality in regard to 'diverging'
HOW long you been doing this??? 
You've
| Quote: |
| been a party to countless experiments (snip) with equipment like this that provides repeatability with the human variables removed |
. . . . Hmmmm . . . you've built a one legged T-000.5 Terminator that (within the limitations of one photo) appears to function on one ski in one plane in a static moment whilst immobile . . . on a variable surface to explain a dynamic system?
This is a wind up and you're taking the p¡ss? 'Cos if you're not you're going to need a ****in' great ladder to get out of the hole you've got yourself into.
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FAQ
