Sean Warman's Concepts - Page 4

 Teton go drop a ball off the deck of the halfpipe.

 CT, I do believe that every time we turn on skis we are using edging movements which include releasing edge angles as well as increasing edge angles.  For that matter, every time we turn on skis we are using rotary movements to some degree, remember managing rotary movements includes a whole spectrum, and pressure control movements.

Back to the "dynamic" fall line discussion.  Imagine if you will, holding a ball between your feet and making a 40 mph gs turn and releasing that ball at edge change?  Where would in go?

For those here that believe "modern" skiing and expert skiing is all edge and pressure and no rotary, I believe Tetonpwdrjunkie could take you many places at Jackson Hole or I could take you many places at Squaw, Mammoth, Alpine Meadows, etc., where you could not make even your first turn without using strong rotary movements.  I would be more than happy to put money on that bet too!

Great day on the slopes today!  

Yup.  That first 180 degree, 2 m radius  turn at 4 mph is a biotch on the SGs.

It's not that modern skiing and expert skiing has no rotary (meaning twisting the skis via direct application of torque through the boot-ski interface); all good skiers are adept at using rotary movements, but only when and where they are needed.

That's actually a good example of only one real fall line.  Whether manmade halfpipe or natural gully (Dick's Ditch, portions of Primrose Path @Snowbird, etc.etc.) the mechanics of turning are dramatically different depending upon whether you're headed up or down a wall or, even starker, above the lip.  Worrying about multiple fall lines doesn't help learn to use that terrain. 

People will talk about line in the pipe as part of managing speed among other things, but that is different from fall line.  (People used to the pipe will generally talk simply about walls to simplify things, with one fall line down the pipe in the case of a manmade halfpipe, but that is because they already know how to manage the walls.)
Edited by CTKook - 3/14/10 at 7:36pm

No argument there!

I like the phrase "momentum induced trajectory" because it is pretty self evident what it means!  I still believe the sensations associated with accelerating straight down the static fall line and the sensations that occur briefly, when the edges are released in a high speed turn, are very similar.  Therefore the "dynamic" fall line correlation  seems to jive, for me anyway.  

I also agree that these two terms should be understood separately.  One includes induced momentum divergent to the static fall line and one begins from any static point.  As soon as the ball gains momentum and is acted upon by an outside force tangent to the pull of gravity, it's trajectory will diverge from the static fall line thus "momentum induced trajectory".  It seems pretty straight forward and applicable to any discussion between instructors to gain a clearer understanding as to why skis pass through flat at different angles to the static fall line depending upon momentum induced trajectory.

Sorry for the delayed response, Bud.  Just back from a multi day trip to Snow Basin.  

Sure there are various ways to turn, steering and carving being the two biggy families of them.  Both require edge engagement.  When carving, the sidecut determines the range of turn shapes possible.  When steering the sidecut determines how much supplemental steering power is needed to produce a particular turn shape at any given edge angle.  Sidecut is an important determinant component of turning.  That's why, in addition to edge engagement, I referred to it.

Bud, please don't look at my presentation of a different perspective on a technical topic as PSIA bashing.  It's nothing of the sort.  I have great respect for much of the teachings of your organization, and have defended it in discussions with those who would universally condemn it.  That said, do understand that no organization is ever at the pinnacle of refinement.   Thinking they are is the source of apathy that brings a fall.  Great organizations are always reinventing themselves, and it's no different with PSIA.  I've personally watched the process take place within the ranks of PSIA for as long as I've been skiing, I've seen it take place in my time here on Epic, and I see it taking place today.  In fact your Messiah Bob is doing his best to drive that reevaluation of thought on a regular basis.  Bravo!  The evolution of thinking that allows these needed changes in technical philosophy and teaching methodology can only come from those with the capacity to think outside the box of current wisdom.  Those who blindly follow the steps laid out for them will never contribute to the long term health of any organization.  Because of that I encourage you to at least consider what I say.  Discard it if you choose, but don't disallow yourself the freedom to even consider new ideas, and certainly don't criticize people for presenting them.  

As far as promoting my product, I use my website here on Epic as a means of helping people.  I have many resources there that can help learning skiers clear their confusions about the specific technical questions they have.  The articles or glossary entries on my site have the potential to help people of all levels, and they have done so for folks here at Epic on many occasion.  Many questions get asked here repeatedly, and by referring people to the materials on the website that relate to their questions I can address those questions without having to reinvent the wheel each time.  I've found it very helpful in trying to help people in the limited amount of time I seem to have these days.  It was actually one of the reasons I created these resources.  After 8 years and countless hours of answering the same questions over and over here at Epic, often driving me to the point of burnout, my website is proving to be a great tool.  I welcome any of the pros here feeling that same "been there done that" thoughts to utilize it too.  

 Rick said, "When carving, the sidecut determines the range of turn shapes possible."

I would argue the flex plays into a bit too.  De-cambering the ski plays a huge role in the turn shape as well.  Couldn't we take a conventional side cut ski with a softer flex and carve a pretty good medium radius turn?  But you said sidecut determines "the" range of possiblities?   Can't we take a modern slalom ski and make gs turns on them?  Can't we tighten the radius of a turn by leveraging forward on the shovels?  I think pressure application may have some influence on turn shapes possible?

 




 

Bud,
Hardpack:
Sidecut and flex work together.  Flex is designed to be appropriate for the forces expected at the design speed and turn shape.  Sidecut is designed so that when the ski is tipped to, and slightly past, the critical angle needed to hold ski in it's groove/snow-platform while those forces are in play the curve traced by the intersecting ski and hard surface will be the shape that gives those forces at the design speed.

You biggest radius you can get the edge of your SL ski to trace out on the snow is the sidecut radius of the ski when the ski is flat.  Once you start tipping it, the radius of the ski-snow intersection line gets smaller.  You can't make it any larger than its sidecut radius.  Skiing a long radius turn with a mis-matched ski-snow intersection radius happens all the time, but it's not the same as skiing a long radius ski with a ski that can match the turn radius your making.  It may be carving according to some definitions, but it's not edge-locked carving.

If there were no limit on how much you could flex a ski you would be able to get any ski to match the smallest turn shape, but there is a limit to how much you can flex a ski.  Typically the LR radius skis are stiffer in order to carve longer turns at  higher forces and not fold up.

Forcing a longer radius ski into a tighter bend by excessive tip pressure will work, but usually in order to "carve" while doing so you cannot sustain it for an extended turn; you carve with half the ski at a time, shifting your weight back and carving with the tails through that same apex as the weight isn't available for both parts of the ski.  Since your turn, or the over-pressured part of it is so short, you can add some dynamics and make it even tighter.  Most people don't have the skill to carve this way, instead they bend the tip, but don't tip it enough to "carve".  In effect it is a steered turn of the non-edge-locked variety for most folks.

Softsnow:  Different kettle of fish
Area of shovel and tail lead to different loading due to snow pressure, and different rates of compression of the snow underneath when additional pressure is applied, thus shaping the platform.  Flex varies how much of pressure you apply gets to the tip and compresses the snow versus how much bends the tip.  The same abrupt move on a soft flexing wide tip that would sink a stiff skinny ski will tighten a turn.  Since I haven't really skied much deep soft snow in a long long time, I'll let someone else explain it in detail. 

Somewhere in between:
Art meets science.

Bud, Ghost did a superlative job of answering, so I'll just add my response as support to what he said.

The new DVD "Going South" is now available if anyone is interested.

Images and Concepts “Going South” is $25 plus shipping and handling of $4.

To order send a check for $29 made out to Sean Warman at

Sean Warman PO Box 9632, South Lake Tahoe, CA. 96158

Carry on.

Rick and Ghost post #101, 

Then please explain to me why my 19.5 meter radius ski which is very soft in longitudinal flex will carve turns as tight as many 11 and 12 meter slalom skis?  You certainly make it sound as though sidecut is the only factor?

I think my experience with this thread perfectly illustrates the value of Sean's dvd. My eyes started glazing over at page two. I can watch the dvd and in my own relative way go out and just imitate what I see. Its more valuable to my learning style the 50 pages of jargon.
Edited by pdxammo - 4/4/10 at 6:04pm

Ghost,

Of course you are right!  IMO, and it isn't humble, most PSIA guys make things way too complicated.  Warren Witherell had it right when he wrote something to the effect that if you can put a ski on edge, and pressure it correctly, "it will take you where you want to go."  Skiing should be that simple, but most people screw it up just like they screw up a repeatable golf swing.  The fundamentals of balance,  being in a dynamic position, carving (once you can carve learning anything else is relatively easy like "rotary" turns, jump turns, racing stivots or whatever), and having a functional pole plant for the type of skiing you do, hasn't changed since I learned how to ski as a five-year old almost 50 years ago.  Surely better boots and skis changed how we apply the fundamentals, but the fundamentals never change.  Just be in balance, put the damn ski (or skis now that we have shaped skis) on edge, pressure them by the appropriate amount in the right place, and they will take you where you want to go.  

agree and not, I'm not sure what PSIA others are in but, our ski school has several tech team members and dcl's and is run by a two-time national. I have only rarely felt confused and things are typically presented in a understandable and repeatable manner and has improved my skiing greatly. If anything I've noticed this teaching system tries to present ideas in several ways to address different learning styles.

If that's your experience, Bud, then you're probably not carving cleanly.  Most likely some steering or tail displacement is happening.  I could set a slalom course and you'd see what I'm saying in the track comparison.  I'm using the classic definition of carving here, clean rail tracks, and the arc to arc variety.  You can steer/pivot/brush a 19.5 m ski much tighter than a 11 m ski can carve.  Therein lies your likely answer.

Bud, I think you're spending too much time off piste.  

 Actually Rick I did ski a slalom course the other day on my 27m FIS gs skis using steering but I have carved very tight radius arc to arc turns on my soft 19m skis as well.  I am pretty sure I know the difference thank you!

So are you suggesting that if I place an 11m sidecut ski on edge and stand on it going 10 mph it will carve the same arc as when I went 20 mph? or when I levered more forward on the tip, or when I increased the edge angle? As long as the edge is engaged it will carve the exact same radius?

and I think your stretch pants may be too tight!

I caught this post in my new posts this morning and thought it was interesting(we all know how much time I spend posting in the instruction forums, eh?)
Since I'm a bit out of the loop on this jargon, and I have faith in your coaching, skiing and ability to communicate on snow,
I would like to ask this....
Example first:
Chasing chair lift shadows I noticed that I was keeping a decent pace and RRtracks(although not as cleanly as the more accomplished skier that was with us), as I picked up speed, I needed to either go further outside the shadows or go longer in order to keep, what I had hoped would be, RRtracks.

Is this what you're getting at?

A soft 23 m radius ski tipped to 66 degrees will edge lock carve the same shape as 12 m ski tipped to 40 degrees - on a smooth hard surface.

If you are tipping the skis that far onto their edges, then you will note the same 9.2 m size turn does indeed occur.  It might be easier to bend a soft 23 m radius ski into a 9.2 m arc than a stiff SL racing ski., but if weight it properly and use the right amount of angulation and counter, that's the turn you will arc.

Actually, Bud, I have noticed that as I get older my stretch pants do seem to be getting tighter, but that's beside the point.  

Sure, as you go faster more forces exist to drive your ski a little deeper into the snow and bend it a bit more, but that's true regardless of the ski you're riding. Comparing different skis at different speeds is not apples to apples.  On any particular slope, carving any particular turn shape, your speed will be the quite similar, regardless of the ski your on, so to keep things consistent in this comparison discussion speed should not be considered a factor.

The hardness of the snow will determine how deeply the turn forces will drive the ski into the snow.  Yes, a stiffer ski may absorb a small bit more of those snow compacting forces, but on a typical firm groomed slope not nearly enough to compensate for the extra bend derived from an 8 meters radius drop in sidecut.   

Think back, Bud.  In the old days, before the introduction of shape skis, skis also came in soft and stiff versions.  Did you see anyone ripping out nice tight arc to arc carved turns of the sort that is possible today?  I'll answer for you; NO!  We did know how to carve back then, but the skis just wouldn't allow such turn shapes to be carved, regardless of how soft the ski.  When the first GS shape ski came out in the mid 1990's it would carve circles around the traditional slalom skis of the day.  Sure, you can tweak a bit less radius by moving fore on your skis, we did that back on our old straight skis too, but it couldn't compensate for more sidecut.  That's why the shape ski revolutionized racing, and skiing in general.  When it comes right down to it, possible turn radius really is primarily about sidecut.
Edited by Rick - 4/5/10 at 6:22am

Trek, it depends.  As speeds grow you may have been adding edge angle.  A ski on a low edge angle may be able to hold an arc at low speeds, but be driven out of the slight platform it's cutting in the snow at higher speeds by the greater forces present.  The jargon term for this concept is "critical edge angle".  That necessary increase in edge angle will do more to sharpen your turns than the speed itself.  

 Um, If I'm maintaining RRtracks and trying to control speed it would stand to reason that I'll turn up hill more, which would imply higher edge angles are necessary, eh?

That first guy really gets a little too far inside to me. Looks like some could get the inside hip up a little.

 pdxammo, that video was not put up for MA, it was put up to show examples of different turn shapes and the edge angles that are necessary for those turn shapes.

Edge angle is independent of degree of turn.  Degree of turn refers to how far out of the falline you turn (see link).  http://www.yourskicoach.com/YourSkiCoach/D.html

You can use degree of turn, turning uphill as you call it, to control speed while employing a variety of turn radii.  When carving, radius is controlled by edge angle.  

In your post you said you were chasing chair shadows.  I didn't understand until this last post you were also apparently trying to control your speed.  Degree of turn and radius are the two means of doing that, and they don't have to be done in unison.  Want to make long radius turns but still control your speed?  Increase your degree of turn.  Want to control your speed but not turn all the way across the falline?  Decrease your turn radius.  Both will work.  Combine them for maximum speed control when carving.  If thats still not enough speed control to suit your taste, introduce some skid into your turns.  The more skid, the more speed control.  

Make sense, Trek?

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