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Speed + Carving + High Gs and inertia = airborn launch

post #1 of 15
Thread Starter 
Hi pros, I posted a similar question in the general forum with many great responses but would appreciate your insights and advices in the event that you did not see that other post.

Basically when carving a high G turn my edges engage so forcefully that I am literally ejected from my path, sometimes tripping outwards (wipe out) and sometimes inwards, within my course (which is not so bad). My concerns have been prompted by my newly purchased race stock SL skis, with even more energy via liquid metal. Until now I have been using all mountain carvers and race stock GS skis.

My technique leaves much to improvement there is no doubt, I have very little race training.

I see skiers, including WC skiers, who are not nearly as physically strong as I am (when fit I squat 550lbs), yet handle these forces with no problems. Your suggestions and or insights. Thank you.

Oh, if this means anything, my edges are meticulously sharp, tune them frequently, base 1, side 2 on the carvers, and 1,3 on the GS skis.
post #2 of 15
Richie-R,

Between the other thread and this one I’m still not quite clear on exactly where you’re being popped out of your turn and in what way. Would you mind providing a little more info?

In particular . . .

1 ) Are you being ejected from both Medium and Short radius turns or just Short turns?

2) exactly where in the turn? (this matters). If we use a clock face on the snow in front of you (6:00=start, 3:00=apex, 12:00=end)
-At what hour does everything seem OK
-What hour does the launch start
-What hour is control/snow-contact lost?

3) (If OK to ask…) How big are you, how fast are you going, and how much do you weigh?

4) Does this happen unexpectedly during a series of Linked Turns - or only when going from Medium to smaller turns?

5) Is your *whole body* being ejected UPward - or is it just your legs being ejected up & Inward, thus bending your knees and perhaps creating a suddenly greater degree of angulation?

6) How steep of a slope is this happening on?

.ma
post #3 of 15
My thoughts on this all lead down to your pressure control management! I applaude(sp?) you on on your squattting skills but strength isn't eveything here! The WC racer has learned how to manage the forces that are created thru the turn over many years. michaelA has some good questions for you that need answers.

One question I have is -Why a race stock ski? They are going to give you a ride! It's all about anticipating the energy of the ski for the next turn,and using that energy to move you down the hill and through to the next! Ok I am rambling now!!

T
post #4 of 15
Thread Starter 
Quote:
Originally Posted by michaelA View Post
Richie-R,

Between the other thread and this one I’m still not quite clear on exactly where you’re being popped out of your turn and in what way. Would you mind providing a little more info?

In particular . . .

1 ) Are you being ejected from both Medium and Short radius turns or just Short turns? Mainly short turns, but also medium if enough speed is involved.

2) exactly where in the turn? (this matters). If we use a clock face on the snow in front of you (6:00=start, 3:00=apex, 12:00=end) 2:00
-At what hour does everything seem OK 6:00
-What hour does the launch start 1:00
-What hour is control/snow-contact lost? 12:00

3) (If OK to ask…) How big are you, how fast are you going, and how much do you weigh? About 5' 11". During short turns about 20-30mph, medium turns maybe 45 mph (I am just guessing). Weight fluctuates alot but last time I was weighing about 200lbs

4) Does this happen unexpectedly during a series of Linked Turns - or only when going from Medium to smaller turns? Not during linked turns

5) Is your *whole body* being ejected UPward - or is it just your legs being ejected up & Inward, thus bending your knees and perhaps creating a suddenly greater degree of angulation? Usually just the legs, but if I stiffen up, the body as well.

6) How steep of a slope is this happening on? NASTAR slope usually

.ma
Quote:
Originally Posted by tcarey View Post
My thoughts on this all lead down to your pressure control management! I applaude(sp?) you on on your squattting skills but strength isn't eveything here! The WC racer has learned how to manage the forces that are created thru the turn over many years. michaelA has some good questions for you that need answers. Yes clearly its my form.

One question I have is -Why a race stock ski? They are going to give you a ride! It's all about anticipating the energy of the ski for the next turn,and using that energy to move you down the hill and through to the next! Ok I am rambling now!! Well, I want to learn and be capable of handling the best. I amde the mistake of not getting a race stock boot, now it looks like its what I shoud have gotten; too soft.

T
Thanks again guys
post #5 of 15
Richie,
From your answers...
Not in linked turns: Take a few turns to establish a rhythm when transitiioning from a longer turn to shorter ones and be more patient tactically. Think of a car trying a sharp turn at 100+ MPH. It would be easy to roll it using that tactic.
The clock face: If things are too difficult during the last third maybe you need to think about being more active earlier in the turn. Don't leave so much work for that last part of the turn. Extend the absorptive phase by starting it earlier in the turn. The forces are overwhelming you and more strength is not the answer. A better finishing stance is. FYI flexing the legs that late can and probably is dropping you aft and inside. Which jets the skis, or they pop vertically, or squirt forward (instant acceleration).
In the other thread I suggested a coach. Why? Well you are looking at making some tactical changes and wholesale technique changes. Neither are impossible here but it is really hard to show you a 3 dimensional example since the computer screen is 2 dimensional.


A drill I would suggest is to get some inline skates and do uphill parallel turns. No diagonal striding allowed. To project your hips and torso uphill you will need to actively absorb the last half of the turn so you have the ability to fall uphill with enough extention left to continue extending all the way to the rise line (when you are facing directly uphill). Film it and have a coach give you feedback about it.
Insofar as the best skis, think application first. If you are racing slalom use the slaloms. They are very specialized tools, you can get them to do all mountain things but that isn't what they are designed to do.
post #6 of 15
Thanks for the refined info. I’m sure your answers will help others mull things over as well. Looks like JASP has already gotten into the same areas I was concurrently writing up. I too think strength is nice to have though not really necessary when dealing with this particular issue.

To me, the key info you’ve provided is the combination of:
- ‘launch starts @ 1:00’
- ‘not in linked turns’
- ‘just the legs - unless a taut body’


'launch starts @ 1:00'
Skiers looking for speed tend to choose a spiral-in turn shape. However they start their turn, the skier straightens-out the turn shape as they progress toward Apex to accumulate speed. Coming out of Apex (maybe from 2:00 onward) the skier rapidly reduces turn radius to complete the desired direction-change creating the Spiral-In shape. (This is sometimes called a ‘Cycloid Curve’ but actually it’s not. A Cycloid Curve is symmetrical whereas the Spiral-In curve is not.)

Reducing turn radius with speed constant increases Centrifugal Force (CF) acting on the skier. A Spiral-In turn increases Centrifugal Force dramatically - often faster than the skier can adjust their CM position to remain in lateral balance over the skis. This seems to fit your ‘1:00 Launch’ model as that’s near the peak increase in CF for Spiral-In turns.

It’s possible you’re holding onto the old turn a bit too firmly - perhaps for speed-control (unconscious or not) or perhaps for an extra bit of direction change. So long as we release edge-angle progressively (after 2:00 or so) and/or un-weight into our new turn we diminish (or avoid) this inherent aspect of Spiral-In turns.


'not in linked turns'
Linked turns tend to demonstrate largely the same radius over a series of turns. It’s generally when making sudden and large reductions in turn radius (Spiraling-In) that we experience the unexpected CF-Ejection thing. Yet it can still happen if we hold large edge-angles too late in turns made on steep slopes with firm or semi-firm snow underfoot.

A person standing upright across a 35-degree slope already has a ‘built-in’ 35-degree ski-to-surface angle. This means the ski’s sidecut is already acting to bend the ski into an arc - with no upper body inclination/angulation needed.

When skiing a steep slope, at turn Apex we might have our skis tipped 30-degrees. If we hold the same body angles and ski-tipping-angle into turn finish on a 35-degree slope we end up with a 65-degree ski-to-surface tipping angle at the end of our turn - the equivalent of a much tighter turn than at Apex.

In effect the slope itself creates the Spiral-In effect when we don’t correctly adjust for slope-angle late in our turns. (This is much less of a problem in soft snow since sidecut is less definitive in turn shape there)

Even if a skier progressively reduces edge-angle late in the turn on steep slopes they might not reduce edge-angle fast enough for the given slope - especially if they’re bracing against the slope late in the turn for speed control. If we don’t reduce edge-angle properly coming out of turns on steep slopes then these too end up as Spiral-In turns.

Just look closely at tracks left on many steep slopes and you’ll notice a lot of linked ‘J-shaped’ turns - turns with a stretched out Entry-thru-Apex while showing a sharply hooked finish. This is a squarish version of a Spiral-In turn.

If you experience this ‘turn ejection’ thing often on steep slopes, this may be worth exploration. Experiment with longer, more progressive finishes that include gradually diminishing edge angles.


'just the legs - unless a taut body'
This is an important thing to notice, implies a lot - and takes a whole lot of analysis to properly explore.

When skiers experience the Spiral-In Turn or the similar effect caused by steep slopes a kind of ‘differential motion’ effect occurs based on muscular tension between upper and lower body.

For the most part, lower body components (foot, lower leg, upper leg, and hip) are laterally aligned perpendicular to the base of our skis whether we’re turning or not. When we Angulate our upper body components are no longer aligned perpendicular to the base of our skis because we’ve tipped the upper body to the side. Any thrust against the base of our skis pushes directly up through the Mass of lower body components - but pushes Off-Center against the Mass of the upper body because the upper body is now to the side of that thrust. Unless we do something to compensate, any unexpected thrust coming up through out feet causes our whole body to Rotate Sideways toward the outside of the turn.

For Spiral-In turns the large thrust against the bottom of our feet increases exponentially due to the rapidly decreasing turn radius. Late in this process the thrust may be so great relative to what we normally perceive that we experience it as a ‘Pop’ or Catapulting sensation.

This is the primary source for the feeling of ‘Pop’, ‘Ejection’ or ‘Rebound’ that we perceive from our skis as they execute a very sharp turn. Ski elasticity (stiffness & flex pattern) contributes to this - but much less so than the sudden angular acceleration caused by the rapid increase in thrust-intensity from the more-sharply turning ski.

---
With this in mind we should consider how a skier’s upper body and pelvis together have much more Mass than lower body components. we also need to realize that the skier controls how much of the energy directed into their skis gets transferred further up the skier's body.

If while Angulated, we maintain passive tension between upper and lower body then any ‘rebound energy’ directed perpendicular into the base of our skis can be used to ‘toss’ our skis to the Outside of the New Turn using energy provided in the last moments of the Old Turn while our upper body continues moving in the same direction it was already going. Relative to the skier, any upward component of the ‘pop’ can be absorbed internally while the lateral component is used to shift our skis to the other side of our body re-orienting us for New Turn inclination.

If we stiffen upper/lower body connective muscles then any ‘pop’ will be partially directed into our upper body Mass offering a variety of potential outcomes. This gets complicated since every outcome depends on an *exact mix* of muscular tensions, degree of angulation, rate of Spiraling-In, execution timing and a well-synchronized position for our CM.

In general though partial muscular tension is probably the most useful allowing us to direct ‘pop’ from our skis into useful purposes like un-weighting, missing a rock, whole-body reorientation into the next turn, etc. Too much muscular tension between upper and lower body is likely to result in an uncontrolled whole-body rotation toward the outside of the Old Turn (being ejected) unless we are moving closely in sync with the rapidly changing thrust from our feet.


OK, that’s quite a lot of analysis, but it does seem to support your experience of ‘just the legs’ being ejected unless you ‘stiffen up’. Since I was in Verbose-Mode tonight, my typing-fingers are quite winded so I’ll leave it to others to provide training ideas and solutions.

.ma
post #7 of 15
Thread Starter 
Fantastic, that was a great analysis by both of you. Reading the responses twice, I am really understanding what is going on, and how your responses depict it EXACTLY. Since I do not rollerblade, I only wish now I had some snow to use this new found knowledge to change my technique.

Before I get back on my skis this season I will reread all of this and try to be conscious of what is going on to make the necessary changes. I will report back. Thank you all again.

If anyone else would like to add anything I am all ears (or eyes in this case). Thanks
post #8 of 15
Thread Starter 
One last question, how much do you think my boot fit comes into play with my problem?

I am having some unwanted heel lift and my boots seem to be softer than what I should be using. Here is the thread concerning my boot situation: http://forums.epicski.com/showthread.php?t=59599
post #9 of 15
Richie,
After reading your boot thread I would say the two pros gave you a lot of good advice. Mosh does a great job and many of my students are his customers as well. If you have the chance to get out to Aspen go see him. If not maybe he could tell you someone closer to home.
post #10 of 15
Richie, you have been given some great advice - just one suggestion to add: ski moguls more often. The problem you mention may be partly a matter of improving your absorption skills.
post #11 of 15
My first post in anything techical in a long time. I have decided anymore that I am not going to get too technical unless I am looking for my own clarification.

The way I see it is that you are too agressive and want on high edge without waiting for it to happen. Your movements may be originating from the hips and upper body (kind of a dive in type feeling). You end up disconnected from the control at your feet and cannot manage the forces. I call this small mountain syndrome, you want more power out of a slope that just hasn't got it. I am guilty of this myself.

The correction: less is better. Wait for the turn to develop and seek the sense of control from your feet. Let the power develop, don't push it.

From an equipment standpoint, boot collapse will also cause this. Boots not being laterally stiff enough to drive the ski you are on.

If you have a big ego, you will likely blame the boots entirely for your problem. Less is better, is better, no matter how stiff or weak are the boots. Just my two cents.
post #12 of 15
From what I am picking up what you are feeling is what we call un controlled "rebound". So what is rebound? Is it an external from the ski, or is it an internal force. The best description of rebound is basically a pole vault. Basically what happens is when all the force builds up at the end of the turn from a direction change we have a choice, hold on, or let go. if you watch WC skiing you will see that the faster skiers all tend to let go at some point. If you don't and you have the ability to squat over 500 pounds you are certainly able to hang on however by hanging on your straight leg serves to act as the pole. as your center passes over the pole your center of mass is traveling at a rather large tangent to the surface of the snow. So you end up launching upwards rather than parallel to the snow. And what happens in the air is not always complementary to re-entering the atmosphere.

Conclusion a bit of softening it the end of the turn will take the bite out of the pole vaulting.
post #13 of 15
Thread Starter 
Mosh nails it. Pole vaulting aptly describes the most disconcerting air born launching I have experienced.
post #14 of 15
What do I win??
post #15 of 15
Thread Starter 
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