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# Where does TURN begin and end? - Page 2

For clarity, I go with the edge change as the transition from one turn to the next. When I am doing short turns, I think of fall line to fall line for a cleaner and seamless edge change.

RW
That means the turn is defined only by what the skis are doing.

I imagine that "release" is equivalent to the moment that the edge angle changes to flat.

The problem with these definitions, is they ignore the path of upper body -- the actual thing being turned or released.
Big E,

Quote:
 The problem with these definitions, is they ignore the path of upper body -- the actual thing being turned or released.
Please explain this, arn't the two quite related?

RW
The release and turn? Sure -- but release can mean release of the center of mass (CM) from it's arc. The skis can continue in their arc quite independently of the no longer turning/deflecting CM. This is quite different from release of edges.

So, how we define turn end is very dependent on which path we are viewing. Sometimes turns do end as you suggest, but not really that often. A traverse would maintain the same set of edges, but all turning has stopped, the CM is no longer being deflected by the turning skis -- the paths of the skis and CM are the same.
Did all the turning stop or did the turn just become exceptionally big? If the CM is no longer being deflected, why is it traversing instead of going down the hill, as it will when the edges are released into a side slip?
Put a ruler on the tracks left by the edges and you see they form a straight line.

A traverse is not a turn. Not even a special case of a turn.

I should say the CM is being deflected in a new direction. That would be more precise.
Perhaps there lies the confusion and inefficiency of turns? The difference in timing of edge change vs. upper body deflecting in a new direction?

I would naively thought if edge release coincide with CM being deflected in the new direction is when a turn is "well executed"?
Yeah, BigE, I wouldn't really call it a turn either. Just trying to fathom the difference between that traverse and dialing in the minimum smidge of turning. Maybe its that more precise new direction.
Quote:
 Originally Posted by Max_501 I'm not saying this is wrong, just trying to understand it. If I'm in the first turn (ie. skis are still on edge arcing up the hill), how can I be in the 2nd turn?
In a turn using inside leg extension to topple the mass into the new turn the turn is borne much before the current turn has been completed . Skiingman is correct in his statement in this scenario but I like BigE's statement that the turn begins with the deflection of mass.This deflection can begin to happen in the fall line.
So it depends on what type of turn you are beginning.Tale of Three turns shows this . Also Ricks post in Physics of the Turn also explain this.
Quote:
 Originally Posted by at_nyc Perhaps there lies the confusion and inefficiency of turns? The difference in timing of edge change vs. upper body deflecting in a new direction? I would naively thought if edge release coincide with CM being deflected in the new direction is when a turn is "well executed"?
There is no question that when the new edges engage, that the CM will start to be deflected in a new direction.

Many things are cleaned up if we simply acknowledge that the purpose of a turn is to change the direction of the CM. Turn start and turn end are then completely obvious.

So what about all the talk saying that the new turn starts when the old turn ends?

IMO, just teaching comments desgined to get some sort of response -- usually to make a smooth change from one turn to the next. But, perhaps a rather poor way of saying it, if you consider that many will rush to the new set of edges or twist the skis impatiently since the new turn is supposed to start immediately. And then what of "neutral"?

Again, that's something that speaks to the relationship of the CM and base of support (BOS) or the skis.

Neutral is usually taken to be the point where the CM is directly above the BOS and the edges are not engaged. So the CM is not being deflected in a new direction. This means that neutral is not part of a turn at all. Which is fine -- it is part of the transition.
Well yes. The turn can be described as when the cm first experiences an acceleration that is not in line with it's current direction of travel. That's how I view a turn. However, with my background of mostly following the fall line and turning in order to follow it or get around obstacles, I found myself confused by many threads until I realized that most of the instructors used the definition I posted up earlier.
I understand the definition that you posted earlier as being the result of the instruction to "complete the turn".

This is the speed control sort of turn that students are encouraged to make. Along with the instruction to "complete the turn" comes the instruction to make the turns "round", and to "turn the feet" to do so. In that way speed will be continually scrubbed during the entire turn. The theory is that you will be able to safely explore the mountain with this versatile turn style.

The result of incomplete turns is that speed continues to increase each and every turn. The most incomplete show very little deviation from fall-line, and on steeper pitches, you generally have to stop to regain control.

If the fall-line runs from 12 to 6 o-clock, then "complete turns" see the skis pointed at 3 and 9 o'clock. A very incomplete turn would be when the skis are pointed at say 7 o-clock. This speaks only to the direction of the skis, while the definition of "turn completion"/"turn end" refers to the CM.

But there is a link between the two that can be made:

A "complete turn" requires that the skis are positioned across the fall line at 'turn completion'.

The resulting round line is the slow line. This is why instructors are like golf carts. They are often seen skiing the slow line slowly; without either athleticism or energy.
Quote:
 Originally Posted by at_nyc On reading the "ski the fast line slow", I suddenly find myself having trouble visualizing what exactly is the first half vs. the second half of a turn!!! So, where do turn begin and end? I'm having a mental block today!
at_nyc,

Has your original question been answered in a way that you can easily understand yet?
Yes, apart from the very fine definition of EXACTLY the point where it begin and end, which wasn't the original question actually.

But I'm enjoying the drift and the discussion. And I think I got a better understanding of turns overall.
Ok then, let's drift some more. The turn begins when you are not happy with the direction you are heading and do something to change it. For me that something is invariably a movement that affects lateral balance. If I'm traveling straight prior to the turn, that movement directly results in a force that is not tangent to the direction I'm traveling in. Lateral movements of the cm due to lateral force changes are directly related to tipping of my skis which is paramount in establishing these lateral forces. It's a bit of a feed back loop.
Great!

So if you don't change anything in your ski nor your upper body, you'll continue going whereever you were going. Until...

Do I understand you're saying you "initiate" the turn by tipping the ski, which then the "lateral force" of the ski wanting to curve more would move the body so it travels in a new direction... if so,

If I tip the ski too much and my body can't change direction to match the lateral force, I fall over!!!

A turn starts when you start changing your direction of travel. It ends when you stop. No need to make it any more complicated than that.
Quote:
 Originally Posted by Rick A turn starts when you start changing your direction of travel. It ends when you stop. No need to make it any more complicated than that.
Hi Rick, good to see you around. I like your simple explanation.

When I think of direction of travel I typically think of the skis but others here think of the CM. So, has the direction of travel changed when the skis are still arcing but the CM has released and is moving down the hill (as in Bud's rotary finish move)?
Quote:
 Originally Posted by Max_501 Hi Rick, good to see you around. I like your simple explanation. When I think of direction of travel I typically think of the skis but others here think of the CM. So, has the direction of travel changed when the skis are still arcing but the CM has released and is moving down the hill (as in Bud's rotary finish move)?
Does it matter? Usually there is a dead spot between turns but maybe sometimes turns overlap. Is that what you are getting at? I don't think you will ever see significant overlap. I also doubt you will ever need to pinpoint the moment one turn ends or another starts. It's much better to flow from one turn to the next seamlessly.
Quote:
 Originally Posted by Max_501 Hi Rick, good to see you around. I like your simple explanation. When I think of direction of travel I typically think of the skis but others here think of the CM. So, has the direction of travel changed when the skis are still arcing but the CM has released and is moving down the hill (as in Bud's rotary finish move)?
The turn has finished for you, but it continues for your skis. Think of having a dog on a leash. The dog's still turning, but you're not. Thinking of your skis as a dog on a leash is also helpful for quickly released cross-under; your legs go slack just like a leash would.
Another way of looking at beginning and ending is to look at the ski tracks in the snow.

RW
Quote:
 Originally Posted by Lonnie Have you guys ever seen the track skis, but more visually, a snowboard leaves in the snow? Is there a point where the track 'disappears'? Where is that point? Hummm?????
Quote:
 Originally Posted by Ron White Another way of looking at beginning and ending is to look at the ski tracks in the snow.
Hummm, that sounds familiar.....
Quote:
 Hummm, that sounds familiar.....
Sorry, didn't see that.

RW
Quote:
 Originally Posted by BigE The turn ends when you stop deflecting the center of mass (CM/body ) in the direction of the turn. A left turn stops when you stop turning more left. The new turn starts when you start deflecting the CM in the other direction. A right turn starts when you start moving the CM to the right.

The only argument I could see is that if you allow the CoM to start moving towards the outside of the turn as early as the apex of the current turn. This could be mis-construed to mean the new turn begins then, even though the path of the CoM is still curved in the direction of the current turn.

Same can be said for the idea that a turn starts when we reach "cross over", which is when the CoM begins moving inside the new turn. The problem is that the edge change can happen at this point, or it can be delayed by directing the skis across the hill for a moment longer using angulation / steering. So we cannot say definitively a new turn starts at this point either since the body (CoM) is in one turn and the feet are still in the previous turn.
As an additional example, I would point out that back in the eighties there was a strong argument made for moving the feet (stepping) to establish a new platform before redirecting the CoM. The logic was that it took less energy and time to accelerate a smaller mass (the lower leg). The equipment of the day did this very well. The down side of this technique is that we were re-establishing a new platform at the beginning of every turn and by neccesity re-balancing on the new platform.

I am hoping that this points out that the exact point when a new turn starts is largly dependent on; the maneuver being employed, how you personally define the start and finish, and on which teaching system you use. About the only thing common to all of these is if you go straight or stop, at any point during a run you are not turning.
My personal belief is that a series of turns requires us to think of them as a set, not as individual turns. So the start and finish of each turn becomes less relevent than the transitions from one to the other.
Quote:
 Originally Posted by justanotherskipro My personal belief is that a series of turns requires us to think of them as a set, not as individual turns.
I like that. Thanks, skipro.
Seamless turns
Quote:
 Originally Posted by justanotherskipro The only argument I could see is that if you allow the CoM to start moving towards the outside of the turn as early as the apex of the current turn. This could be mis-construed to mean the new turn begins then, even though the path of the CoM is still curved in the direction of the current turn.
Misconstrued is correct! The CoM is still arcing in the same direction, albeit not as strongly.

Quote:
 Originally Posted by justanotherskipro Same can be said for the idea that a turn starts when we reach "cross over", which is when the CoM begins moving inside the new turn. The problem is that the edge change can happen at this point, or it can be delayed by directing the skis across the hill for a moment longer using angulation / steering. So we cannot say definitively a new turn starts at this point either since the body (CoM) is in one turn and the feet are still in the previous turn.
The idea that parts of the body are in different turns always will give people hiccups. That is why the definition being offered looks only at the CoM. The feet continuing to arc in the previous turn is a separate "windup".
E,
It certainly makes it less complex to only mention the CoM but it also gives the impression that the whole body is moving as a unit. Somewhere there needs to be follow up that explains the timing of movements for the different parts of the body. Ideas?
Quote:
 Originally Posted by justanotherskipro .........My personal belief is that a series of turns requires us to think of them as a set, not as individual turns. So the start and finish of each turn becomes less relevent than the transitions from one to the other.
good point. you can not clearly break the series of different maneuvers which begins and ends in various points in the turn phrases.
Quote:
 Originally Posted by justanotherskipro E, It certainly makes it less complex to only mention the CoM but it also gives the impression that the whole body is moving as a unit. Somewhere there needs to be follow up that explains the timing of movements for the different parts of the body. Ideas?
Simple awareness of the different paths that the body and the skis take will go a long way to remove that mistaken impression. So will teaching and practicing movements that create upper and lower body separation.
In fact anything that gets the upper/lower body and inside/outside halves moving independently and increases the ROM of flexion/extension will help create this awareness.

eg. If the student can do it, just ski moguls! Find light blue moguls ski REALLY SLOWLY -- as slow as you can! That will greatly help the element of timing and coordination, of the flexion/extension, tipping/flattening, fore/aft balance movements, poling, etc.
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