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# Moving inside the arc - Page 2

Quote:
 Originally Posted by Ghost Maybe you are skiing too slow and your skis have too big a turn radius and your snow is too soft. I just did this last Saturday. The cm does not hit the snow. Without further action, on 13-m skis on snow hard enough for the sidecut to make a difference, arcing, the increased tipping angle due to the legs attaching the cm to the skis causes the turn radius to be high enough that centrifugal force MV^2/R (about 3 or 4 g's at about 35 mph edit: I think speed was closer to 25 mph, could have been as low as 20 mph I didn't have GPS on me) and the down-slope component of gravity prevents any further falling despite the fact that all the force is on the outside edge. Now if you counter a bit more so you can angulate (I think that's the best way to describe it)a bit more you can get that cm down there and then bring the turn radius back down to join it.
Ghost, my suspicion is that in your testing you did not have much weight on your inside foot when you began relaxing the inside leg,,,, or,,,, you increased your angulation as you began to topple to the point of quickly becoming well balanced on your outside foot. It's very easy to do.

If I'm understanding you correctly, and the downhill component of gravity is a fly in your ointment, you're developing your edge angle too late in the turn cycle. Tip more aggressively above the falline. There gravity will be on your side.

Or, if I have it all wrong, then congratulations,,, you've just invented a new transition. To initiate a transition, ski through the turn with equal weight on inside and outside ski, then simply relax the UPHILL/INSIDE leg. The edge angle will momentarily increase, then the forces will quickly step up to hurl your body across your skis and into the new turn. We'll call it ILR (Inside Leg Relaxation)
I think you're onto something here Rick, and it isn't a new transition. If I recall correctly at the apex of the turn, skis are parallel to the fall line, I'm pulling 3 gs, all of my wieght is on the outside edge, none on inside ski, and the stool just wouldn't topple any farther.

If I'm balanced on the outside edge at 3 gs, then the cm won't drop; it's balanced.I can drop quickly before pulling those gs if I want to see 3.5 gs, but that's not the task. The task is how to increase edge angle and decrease turn radius from a balanced position in a hard turn.
OK, Ghost, now we're making sense. No, the body won't topple via relaxing the inside leg if you're fully balanced on your outside ski. You need to do something to change your lateral state of balance. That happens through changing your angulation.

Next time you're skiing, try this; Develop those maxed out angles your talking about early in your turn, well before the falline. Then as you come into the falline riding that angle, aggressively drop your inside shoulder and tip your torso into the turn and down toward the snow. Remove all counter as you do it and square up to your skis. If you do it right you should feel an instant balance change to your inside foot. Then quickly relax your inside leg. Your edge angle will increase. Be ready to quickly re-introduce angulation when you get tipped as far as you want, to avoid eating snow.

The other, better alternative is to start tipping immediately upon turn initiation, and keep tipping until you reach the ultimate edge angle you want for the turn before establishing total outside ski balance. Remember, as long as we're tipping, we're not in a state of balance equilibrium.

Also, most people will not be 100 percent outside ski balanced. There will be at least a fractional amount of weight on the inside foot, if only resting on the snow. It's enough to adjust tip angle via relaxation of that lesser weighted foot. A reason you might want to experiment with shifting at least a tad of your weight to your inside foot through your arc. Try it and see if after the fact angle adjustments via ILR are easier. Exaggerate to 50-50 to really test it.

Good luck.
Quote:
 Originally Posted by michaelA Actually... this depends entirely on the sidecut of the ski and the speed of the skier. We don't know for sure whether the skier will topple inward or outward until we understand the exact speed and resulting radius caused by the increasingly tipped ski. It's possible to design a ski such that we can easily fall to the inside for typical turns (straight profile) and equally possible to design a ski such that we invariably fall to the outside for typical turns (very shaped profile). Many people like certain skis more than others for just this reason. When a ski seems extremely easy to turn and is super easy to balance on (laterally) then this 'perfect ski' (for you) probably has the ideal sidecut for your typical speed and for your personal biomechanics. for this reason alone, people with long bodies and short legs will seldom like skis favored by people with short bodies and long legs. .ma
Michael, the shape of the turn, amount of sidecut, and speed are already baked into the balance equation cake when you're skiing along through a turn in a particular state of balance. If the point of balance is anywhere between the feet, and you remove one of the feet from the balance platform, the body will immediately become out of balance and begin toppling toward the removed foot. That's how the well known OLR works, and it doesn't matter what ski is being ridden,,, it works.

And, all skis are easy to balance on if you have the skills. A better plan than looking around for a ski that seems easy to balance on, is to build your skills so that ANY ski is easy to balance on.

Different body types don't need different skis, they just need to use different angles and positions to achieve balance. Doesn't matter what skis their on, it will always be the case.

Matching the ski to the speed only applies to helping shape the turn needed to ski at those desired speeds. So, choose a slalom radius ski if you want to carve, but don't want to do it at mach schnell. If you like higher speed carving than break out the GS cuts. But it has nothing to do with balancing on either of those choices. Either can be easily balanced on once good skills are developed. And it has nothing to do with how your transition will work. OLR works regardless,,, so does ILE.

Oh wait,,, sorry,,,, I just noticed you weren't talking me, you were talking to Rock. Or is that my nickname now?
Oops, sorry about the 'Rock'. I just type HyperText Markup Language (html) directly into the editor rather than using the buttons to create quotes. Danged bandaid on the O/I finger right now...

While I understand what you're saying above you actually talked completely around the specifics I was trying to point out. Forget your two-footed skiers for a moment and instead picture a one-legged skier carving forward on flat terrain with a specific sidecut at a specific speed who is in perfect lateral balance for the angle their CM & skis are at (just picture them with pure 'banking') ...

-If this skier now angulates (rather than just inclining the CM more) then they will automatically be out of lateral balance and will topple to the Outside. This is because they now have an edge-angle at the ski that produces a smaller radius than when they were formerly in balance. Since speed didn't change, the CF will now be greater, pulling their CM to the Outside.

- If our one-legged skier manages to incline their CM a few degrees without angulating (say by raising the Inside-Arm suddenly) then whether they end up out of lateral balance to the Inside or Outside would depend entirely on the sidecut of the ski.

A large-radius sidecut ski might not diminish its turning radius enough at that speed (and new angle) to support the new angle of the CM (so they topple to the Inside). A small-radius sidecut ski might diminish its turning radius too much at that speed (and new angle) and cause the insufficiently inclined CM (and ski) to be driven back to the original in-balance angle (driven to the Outside). Lateral momentum created by this might be enough to cause them to topple even further to the Outside (past being in lateral balance).

Of course, none of this considers effects caused by flexion/extension and by the canging slope angle under the skier as they progress through the turn (which complicates things further).

---
I would agree that with two legs/feet we have many more options and any good skier makes use of these options all the time. All I'm saying is that we should spell out exactly what's really going on and keep it clear which skier-actions contribute what effects in their actual turn. A Lateral Balance concept that depends on two-footed interaction is not the same as Lateral Balance concepts in and of themselves I just think we should avoid blanket statements that mix the two up.

Quote:
 Originally Posted by Rick Different body types don't need different skis,...
I'd also agree that different body-types don't 'need' different skis - but I think different body-types can benefit greatly from skis appropriate for that body-type and the usual speeds that skier likes to travel. I think sidecut can make a *big* difference in how well a ski will perform for each given skier's body type and usage pattern.

.ma
Good stuff Weems.

Our SSD was always saying "ski against the ski, not on the ski". Weems platform is another way to think about this same concept.

Also within this framework, moving inside the arc is not a goal in and of itself, just part of what we could/should do to build the platform needed for the current speed/slope etc

The leveling of the shoulders (reverse angulation?) also fits in well with the platform.

Quote:
 Originally Posted by weems This is a cool subject, and lots of interesting answers. And I actually agree with most of them (Except that I don't really feel comfortable with the idea of getting my skis away from me. I understand the metaphor, but I don't really use it.) I would only like to add a context here that, in my view, it is not so much that I want to tip the ski up on its edge, but rather, I want the ski to cut a platform/surface out of the side of the slope for me to stand on. You cut, maintain, and get support from the platform as you go. With sufficient pressure and angle of the platform to the slope, the platform will curve in the direction you want to go as you cut it. This is what I called platform management in a post last year. With this in mind, the "getting inside the arc" has a slightly different meaning, in that I no longer think of being "inside" the turn, but rather that I align myself with, and balance on, the platform that I am establishing. Because that platform is at a certain angle to the slope, it will require (if I'm to use the edges of both skis more or less equally) that I increasingly have one leg shorter than the other, since the platform of one ski develops "higher" (virtually) than the platform of the other. So in this context, I'm not getting inside at all, but rather just aligning my stance to the two platforms (different flex patterns for each leg in order to create more or less parallel platforms), and doing so with awareness that the "new" pull in such an arc is not gravity pulling me into the earth, but rather centrifugal force (or whatever you want to call it) pulling me to the outside of the turn. Visually, you see me inside of the turn, but dynamically I feel like I'm just standing on a new slope within the one I'm skiing down. And the new slope changes it's pitch and curve constantly throughout the turn.
Doc,
I would add a word of caution here though. Many skiers mistakenly take that to mean we should block against the skis in a static way. To me it's the difference between finding a static balance point on a static platform and actively balancing on a constantly changing platform. The bus analogy I mentioned earlier is meant to point out this difference. It should also explain what is meant when you read someone suggesting that we need to "balance in the future"...
Michael, I didn't talk around what you were saying, I was trying to provide a dose of reality. If you do something to throw yourself out of balance to the inside you're going to start toppling inside, and if you don't do something to correct that imbalance, via increasing angulation, you're going to keep toppling till you hit the snow. It doesn't matter what radius ski you're riding, the increase in edge angle will not save you.

If you don't believe that, then all I can suggest to you is to try the little experiment I assigned Ghost. Use any skis you like, and do it to the letter, and I take no responsibility for injuries that may occur from slamming yourself into the snow because you have been warned.

You can do it on one foot too. Just do something to throw your self out of balance to the inside, then do nothing else. ILR has not been invented as a transition technique because it does not work.

As far as matching body types and typical speeds traveled to a particular ski,,, you're half right. Match the skis to the current skills and speed preferences, sure,,, but not the body type. Focus on the skills, man. Don't try to cater to skill limitations. Any person has the potential to operate any ski well. Their body type has little to do with it. Positions to establish balance will look different in different people, but each has to go through the process of learning them, and the difficulty of the process has little to do with body type. If differences exist, they have more to do with athletic backgrounds.

Look on the WC, you see many different body types performing at a world class skill level. Each looks different coming down the slope, a byproduct of different body types, but each is performing at a level most only dream of. And many of them perform at that level in multiple events, on multiple types of ski, at multiple speeds, making multiple types of turn shapes. As an instructor I strongly advise you to abandon this ski to body type belief you have. It assigns a perceived handicap to your student right off the bat that will do nothing to help them improve their skills to the point of being able to ride any ski in total comfort and with supreme skill. Getting your student, and yourself, to that skill level should be your sole focus.

I've taken 100's of students to such skill levels. Within those hundreds of students were every conceivable type and shape of body. Those students got where they did by focusing on skills, not skis. The skis mattered little. The development process worked equally well on straight skis as it does now on shapes. Trust me, Michael, with this different skis for different body types thing you're really trotting down the wrong trail.
Quote:
 Originally Posted by Rick Next time you're skiing, try this; Develop those maxed out angles your talking about early in your turn, well before the falline. Then as you come into the falline riding that angle, aggressively drop your inside shoulder and tip your torso into the turn and down toward the snow. Remove all counter as you do it and square up to your skis. If you do it right you should feel an instant balance change to your inside foot. Then quickly relax your inside leg. Your edge angle will increase. Be ready to quickly re-introduce angulation when you get tipped as far as you want, to avoid eating snow.
Making progress. Not how I would have explained it but I agree with the concept of rotating hip-facing direction to enhance ability to change level of cm. If in a hard turn before the fall line, with upper body pointing down the hill from previous counter you square your hip up with the skis instead of just waiting for the skis to catch up with the direction as you unwind you will be able to drop that cm an then reapply the wind up to prevent toppling into the snow. Not need to put the support on the inside leg and then relax it; just keep it relaxed and let the cm drop.

I also agree with Michael. If your going fast enough and you tip the skis more as you fall into the turn the decrease in radius can be enough to keep you off the snow. Don't forget the closer you get to horizontal, the closer that radius gets to zero an the cos function is pretty steep at the extremes.
OMIGOD..... re-introduce windup = re-introduce angulation.

What a riduculous turn this thread took..... start your own next time!
So, to summarize, it seems that there are several thoughts:

1) Balance atop the changing platform
a) Where you change edge angles with leg/foot action.

2) Balance atop the changing platform
b) Where you change edge angles the by moving inside.

3) Balance atop the changing platform
c) Where you anticipate the effect of edge angle changes through experience.

BigE,
Are you saying we have re-invented the wheel?

I've been reading a lot of your posts this past week or so, and it is obvious, even to an ignoramus like me, that you really know what you are talking about. You have obviously studied this and gone through training. Believe it or not some of us who have had only three lessons, but like physics and enjoy high performance skiing don't know as much. If this forum were just for the know it alls, it wouldn't be of much use.

Rick. It's definitely a speed thing. I fall in too far at slow speeds, but not at typical speeds I like to bend my SCs at. Also facing the outside of the turn more seems to allow better control of angulation to tighten the turn at all speeds I was able to try today. It seems odd that it would work both ways: allow cm to move in without tipping too much at high speed and allow skis to tip without moving cm in too far at low speeds, but it does. I guess the joints work better in that alignment. (I have never studied kinesiology - I can't even spell it without google)
E,
Balancing on a moving platform requires us to use a variety of movements. Galileo offered the idea of perspective to explain all of this. A boat sailing by moves as a unit. A sailor standing on the deck would be balancing on the boat and moving as part of that unit. Varying our stance to dictate our line still requires us to move with the skis. Much like the sailor who is balancing on the boat.
How you choose to do so depends on your school and their prescribed techniques. Bottom line here is that you still need to move with the skis regardless of what they do.
I 'll try to understand what is the summary and how to translate this summary to real skiing. Here is what comes up to mind.
Quote:
 Originally Posted by BigE 1) Balance atop the changing platform a) Where you change edge angles with leg/foot action.
movements starts from feet up?

Quote:
 Originally Posted by BigE 2) Balance atop the changing platform b) Where you change edge angles the by moving inside.
movements starts from body down?

Quote:
 Originally Posted by BigE 3) Balance atop the changing platform c) Where you anticipate the effect of edge angle changes through experience.
Like walking, we don't need to know anything to walk?
Quote:
 Originally Posted by justanotherskipro How you choose to do so depends on your school and their prescribed techniques. Bottom line here is that you still need to move with the skis regardless of what they do.
Agreed on both statements. IMO, teaching ski technique "from the ground up" has many benefits.

First off, as jdistefa put it: Ski technique is about getting the skis to do what you want them to do.

So, in that light, it makes very good sense to teach how to directly manipulate the skis -- tip the feet, move the knees etc. First teach movements that are closer to the snow, and directly impact the platform on which we balance.

The direct focus on what the skis are doing causes the skier to react to the changing platform -- not the other way 'round, where movements higher up the body are the prime movers of the skis. Then upper body movements can be ingtroduced that are supportive of the efforts of the feet and legs. After all, it is the movements that are higher up in the body that we wish to tame when teaching new skiers.

As the student progresses, their focus clearly shifts -- what can they do with the upper body to improve the movements of the lower body? How does momentum help to create effortless skiing? What changes do I have to make to the platform or relationship between the platform and the Center of Mass? ie. what changes to the balance point will support my intent?

To my thinking, ski teaching should start at the lower end of the body. Whether you teach a wedge based progression or whether you teach a direct to parallel approach, it is critical to establish that all movements we make have their effect where "the rubber meets the road" -- at the ski/snow interface. And quite simply, IMO, that's where the new students focus should be placed -- the rest is a consequence of balancing atop that platform.

Experience does help with establishing "directional/diagonal movements" across the skis. But to start with this sort of movement to create edging as a building block of skiing would be unfair -- it links the movement to the speed of the turn, the terrain, and the radius of the ski. Much different movements occur when skiing 12 M / 16 M or 21+ M radius skis.

However, they are ALL related to how the ski/platform behaves on the snow. So, if you do understand how the ski functions, at least to the point where you can sense the required balance shifts, your movements above the ski will have a certain similarity -- as opposed to a drastic difference. There will be much less "gambling" on getting that directional movement just right if the platform is first built by the lower body.
Mmmm... Xmas pictures. A thousand words and all that . Enjoy!

Gee, until now, I'd never realized "Boot Out" was possible on a motorcycle.

.ma
My old boots were beveled from the road; I didn't have knee pucks (just jeans. Yes, road rash happens) and didn't want to scrape my knees off.

The inside hand position is very interesting on biker number 3.
Quote:
 Originally Posted by BigE The direct focus on what the skis are doing causes the skier to react to the changing platform -- not the other way 'round, where movements higher up the body are the prime movers of the skis. Then upper body movements can be ingtroduced that are supportive of the efforts of the feet and legs. After all, it is the movements that are higher up in the body that we wish to tame when teaching new skiers. As the student progresses, their focus clearly shifts -- what can they do with the upper body to improve the movements of the lower body? How does momentum help to create effortless skiing? What changes do I have to make to the platform or relationship between the platform and the Center of Mass? ie. what changes to the balance point will support my intent? To my thinking, ski teaching should start at the lower end of the body. Whether you teach a wedge based progression or whether you teach a direct to parallel approach, it is critical to establish that all movements we make have their effect where "the rubber meets the road" -- at the ski/snow interface. And quite simply, IMO, that's where the new students focus should be placed -- the rest is a consequence of balancing atop that platform.
I use to believe this but I think this approach has the added hazard of creating robotic static skiers. Ski instructor turns if you will. Perfect little feet under a static upper body. All skiing from the feet up. Their CM move inside and in balance all the time. These skiers are also using inefficient upper body movements but they were never taught anything to do with the upper body other than let it ride and keep it quiet. If you don't teach upper body movements you are going to get default movements right from the start.

Is teaching strictly from the feet up a bad idea? No I don't think so but I look at it as an exercise and not "The way to ski" or "the way to teach". To me teaching is all about letting inefficient movements that interfer with CM flow fall by the wayside and letting efficeint movements that allow the CM to flow freely to take over. That includes both upper and lower body movements around a stable core.

I think its very important to have some focus on CM movement right from day 1. The transfer is right there as CM movements are important in everyday walking.

For me the platform is unreliable and the only reliable thing involved is the CM. I have a predetermined idea where I want the CM to go whether its walking, riding a bike or skiing and beginners have this same idea right from day one. I want to use movements to compliment a dynamic CM flow rather than use movements from the unreliable platform to effect movements of the CM. To me this is more of a change in perspective than a fundemental change in the way we should ski.

I guess I come down on the side of CoM centered skiing based around the skiers intent and let the feet do what they need to do the keep up. For me, from the feet up exercises is all about training the feet to keep up not in training the feet to determine where the CM goes. Moving inside the arc should be intuitive controlled by intent but happen in a planned trained way.

If I have a static skier who is skiing with perfect little feet that. I am going to do what I can to upset the apple cart and get the center of mass unstuck and if the feet suddenly do all kinds of things like stepping, wedging, diverging and everything else, I am still thrilled. I can always train the feet to coordinate in the way they should have in the first place.

Again, much of this is a perspective approach rather than a fundemental change in the way we should ski. Maybe I am all washed up at this point with to much zen in my teaching and not enough on total foot movements. I like to think I am well balanced in my approach like Weems sports diamond.
Quote:
 Originally Posted by Ghost The inside hand position is very interesting on biker number 3.
notice he is no longer looking where he is headed, but rather at that inside hand!
Quote:
 Originally Posted by skier_j notice he is no longer looking where he is headed, but rather at that inside hand!
He could very well be headed in that direction.
Pierre,

In either case, there is a disconnect with what is going on..... the foot based approach fails to address the use of momentum to carry the CM into the new turn. This is more and more critical as the pitch gets steeper and steeper.

The CM based approach fails to address the quality of the platform being built and the functional tension required to move with that platform.

IMHO, the key element is to "move with the platform".

That is something that takes more than just experience/time on snow. It takes a good deal of understanding the relationship between CM and platform, and the relationship between the path of the CM and the path of the skis. I'd like to think that focussing on that relationship is one road to expert skiing.
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