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# A Tale of Three Turns - Page 2

Quote:
 Originally Posted by Little Bear Extend one leg and flex one leg to change edge. Flex both legs to change edge. Extend both legs to change edge. Ursula
May 21, 2007

Dear All:

Bravo !!! Among a lot of other details, mainly I couldn't figure out the difference between (1) and (3) except that BB was standing a lot taller in (3) when compared to (1) at transition. Thanks to all for the further edification of my skiing knowledge.

CharlieP
Quote:
 Originally Posted by Little Bear 1. Extend one leg and flex one leg to change edge. 2. Flex both legs to change edge. 3. Extend both legs to change edge.
Well, I liked RicB's description way up there at post #8, but Little Bear's succinct description and its relevance to recent threads make it most likely the one that nails Bob's intended exploration.

Still, I'll keep it interesting and mention that even if precisely true and accurate to Bob's demonstrations - doesn't negate the possiblilty of Inside/Outside/Balanced-Bias turn initiations...(Though I'm no longer in a hurry to check my Lottery Ticket...

.ma
I agree that Ursula has boiled RicB's description down to its essence, but I do like the term "cross through" that he introduced in his explanation, as it seems to be the golden mean of transitions.
Quote:
 Originally Posted by Little Bear Extend one leg and flex one leg to change edge. Flex both legs to change edge. Extend both legs to change edge. Ursula
Folks, in montage 3 observe what the outside leg does (from a flexion/extension standpoint) between images 11 and 13. It flexes (shortens). That is the mechanism being used to initiate the release of the CM to end the turn and "change edges". It's OLR it action, friends. The amount of extension that occurs after that point is of limited significance beyond the desire to display a particular position, because release and force driven tipping into the new turn have already begun.

The same happens in montage 1. The only difference is Bob extends less through the remainder of the transition after release. But the release mechanism is the same.
Now, if you'd like to see the difference between well executed ILE, and the OLR release Bob seems to be using, watch Nyberg in the freeskiing collection on this link.

http://www.youcanski.com/video/video_index_en.htm

Watch Nyberg's outside leg. It does not flex like Bobs does at the end of the prior turn. It does not flex until well after the old inside leg begins to extend. Clearly, Nybergs first move (his release move) is the extending of the old inside leg. A clear contrast from Bob's end of the turn outside leg collapse.

In fact, if you look closely, you can see the result of Bob's outside leg collapse. Load is suddenly dumped on the old inside leg, and it too collapses slightly as it struggles to resist that load, then proceeds to extend. Nyberg displays none of the old inside leg collapse because load does not begin to transfer to it until it's already extending. The old inside leg extends into the load transfer.
Quote:
 The amount of extension that occurs after that point is of limited significance beyond the desire to display a particular position, because release and force driven tipping into the new turn have already begun.
Well Rick, I find myself disagreeing with you here, and the reasons are right there in what you said above.

Speaking of #3 here. To me the path of the com above the snow and the "position" of the legs length are very relevant to the movements available to further shape and vary the turn. Otherwise, all we have is a force driven transition. In #3 we have severely limited our ability to tip down low in the kinetic chain to help develope early edge angle and lead our com into the turn, along with losing the ability to effectively manage pressure in the top of the turn. there is no extending to the edge, the extension is used up, and at this point early in turn, the Com is moving away from the ski with no length left in the leg to reach for it.

For me I think there is real relevance to the lack of ability to manage pressure early in the turn in both #2 and #3, and also the ability to manage edge angle lower down in the body in #3.
Question:

In the last turn sequence it looks like there is a lot of inclination to the point of banking at one point in the turn. Is this a camera angle thing?
Quote:
 Originally Posted by Little Bear 2. Flex both legs to change edge.Ursula
Are both legs being flexed to release or is the outside leg being flexed to match the already flexed inside leg?
Quote:
 Originally Posted by volklskier1 Question: In the last turn sequence it looks like there is a lot of inclination to the point of banking at one point in the turn. Is this a camera angle thing?
Both turns, just after he assumes a neutral position ,he enters the turn in a banked position.
Why?
Is this because , in this type of turning style, the turn initiation move is a weak one and banking is needed to pressure the skis and get the turn underway?
"Hint: The transition is the key...."

For the sake of the "transition is the key" discussion: It doesn’t really matter what happens before or after the actual transition. (For instance: if Bob in ANY of the turns would have hit a bump with the outside ski just as he came to the apex of the turn, his outside leg would have been flexed just like the inside leg.)

I picked the following frames for the analysis:

Sequence #1: frames 20 to 24 (22 being the one where both skis are flat on the snow)
Sequence #2: frames 10 to 12 (11 being the one where both skis are flat on the snow)
Sequence #3: frames 14 to 16 (15 being the one where both skis are flat on the snow)

All the other frames can be disregarded for the transition question.
Ursula
Quote:
 Originally Posted by RicB For me I think there is real relevance to the lack of ability to manage pressure early in the turn in both #2 and #3, and also the ability to manage edge angle lower down in the body in #3.
I used the qualifier word limited for a reason, RicB. I did not say none. I tend to chose my words carefully.

And there was a reason I chose to say limited, and not major. RicB, you're talking about theory. I'm observing what's actually occurring in the 3 montages Bob provided. That Bob is able to produce basically the same turn shape in all three montages, develops the same amount of edge angle, and maintains relatively good lateral balance, shows that any reduction in the ability to create artificial early pressure via post neutral leg extension was not a major issue,,, as I said in my post.

Post neutral leg extension is not a manditory element in producing the turns Bob is here (obviously). Momentum will help power early engagement and pressure. In high energy carving it's often not necessary to supplement early pressure with significant force generating leg extension. It wasn't for Bob,,, it's not for Nyberg in the link I provided. Hip angulation and counter are there to help out if needed, to add a bit of pressure to the new outside ski and get it arcing, though in Bob #3 it was initially not. Usually more needed on flat slopes at slow speeds. How quickly and how much one allows the new inside leg to flex provides control of the rate and magnitude of edge development. Combined with proper angulation, all the forces needed to provide balance are generated via tipping alone, regardless of the edge angle desired. There are no limitations.
Quote:
 Originally Posted by Little Bear All the other frames can be disregarded for the transition question.Ursula
Ursula,,, a transition is the sequence of movements that cause one turn to come to an end, and the next to begin. For that entire process to happen, the CM first has to be released from the old turn. Something has to be done to foster that release. It's that initial move which is the origin of a transition, so to accurately discuss a transition that initial movement has to be taken into account. Just focusing on the period in which the CM is crossing over the feet does not do that. It doesn't recognize the initial movement which caused to CM to move towards the neutral point you're focusing on. One must come to understand the entire transitional process if one is going to gain a clear understanding of transitions, and how they vary.
Rick, am I the only one who sees a marked difference in the time and distance in the transition of #3? Using the skis length as a gage I see it taking the skier much longer time to move through transition and into the next turn. I see the skier moving much farther across the hill in this turn. Really I see the turns all having slightly different transition times and to varying degrees slightly different radius. It would be nice to see the video.

To me this reflects why the movements the skier makes throughout transition is relevant. Even when the initial start of the release is similar.

The theoretical aspect of this comes into play when one states that all three turns should be in a skiers bag of tricks. The variations in the movements through transition and the variable outcomes available to a skier from these differing movement patterns speaks to the reasons why versatility requires all three. IMHO
Quote:
 Originally Posted by RicB Rick, am I the only one who sees a marked difference in the time and distance in the transition of #3? Using the skis length as a gage I see it taking the skier much longer time to move through transition and into the next turn.
I was under the impression and I could be mistaken that these montages are often expanded.
Hey Bob, if you’re lurking out there watching - perhaps you might reveal the underlying video these montages were derived from…? It would be interesting to see if we each see the same things as seen in our initial take on it or even develop new ideas from the addition of motion.

Not sure that ‘Precision Observations’ are provably relevant when reviewing still images. As Little Bear mentions, a lump in the terrain (or any inconsistency in the snow surface for that matter) can briefly distort the overall intended demonstration. Likewise when we’re watching students we generally take care to eliminate such terrain-induced anomalies from our overall movement analysis of the student’s overall technique.

I find still images most useful when presenters are trying to illustrate a particular point and not very useful in trying to ferret-out skier intentions.

---
While I still favor Little Bears assessment over my own initial response, below is a description of what I was looking at initially (suggesting Inside-Ski / Outside-Ski Dominance as potentially being Bob’s theme to seek out).

In the first sequence I estimated that edge-change took place somewhere between frames 22 & 23. In those frames I notice Bob’s downhill foot (New Inside) is still well behind his uphill foot and remains so even at frame 24. Such would be required for a turn initiated with weight remaining primarily on that foot during acceleration into the new turn - or the skier ends up with Fore/Aft balance problems. I also ‘perceive’ that Bob remains balanced *mostly* over that downhill ski until frame 24 or so. For me, this hinted at a New-Inside-Ski dominant turn entry.

For the second sequence I get the sense that both skis are firmly planted in the snow and Bob’s lateral balance seems equally distributed over both skis throughout transition. While the Extra Flex so readily evident strongly suggests a deliberate un-weighting / flexion during edge-change, it’s also a common artifact of a skier deliberately keeping equal pressure on both skis.

With one Straight leg and one Flexed leg we find it much harder to detect the degree of pressure on our straight leg because it’s so strong when straight. When asked to “Keep equal pressure on both skis” Most people will unconsciously perpetually ski in a more flexed stance. Still - with as much flex as Bob is showing in sequence #2 I’m guessing it points more to Ursula and RicB’s themes than my own suggested possibility. Also, demonstration of a ‘Flexing Transition’ in a medium (or longer) radius turn would likely produce just such an exaggerated Flex over the extended transition time.

In the third sequence I first noticed what *appears* to be a lifted downhill in blurry frame 5 - indicating all weight on the New Outside-Ski just prior to new-turn initiation. In frame 14 I think I see another (blurry) partially-lifted ski tip on the downhill ski - again indicating weight already on the uphill ski. I also have the sense in frames 14 & 15 that Bob has shifted his balance over to that new Outside-Ski manually - rather than waiting for turning forces to do it for him.

A common pattern when skiers use an early weight-shift onto their new Outside-Ski is a ‘stepping forward’ appearance thru transition. If we look at frames 13, 14 and 15 - I think I see something a little bit like that - a stepping action off the old Outside-Ski with an active movement of that Foot, Leg & Hip which appears as an ‘up and forward’ motion in relation to the other side. Still - this pattern also supports the idea of an “Extension Transition” as well.

Heck, even if my initial analysis did not catch Bob’s intended theme ...I wonder if in the course of producing his intended theme he also (unconsciously) implemented some measure of a Ski-Dominance theme…? The two themes seem to work very well together.

.ma
Quote:
 Originally Posted by RicB Rick, am I the only one who sees a marked difference in the time and distance in the transition of #3? Using the skis length as a gage I see it taking the skier much longer time to move through transition and into the next turn. I see the skier moving much farther across the hill in this turn. Really I see the turns all having slightly different transition times and to varying degrees slightly different radius. It would be nice to see the video. To me this reflects why the movements the skier makes throughout transition is relevant. Even when the initial start of the release is similar. The theoretical aspect of this comes into play when one states that all three turns should be in a skiers bag of tricks. The variations in the movements through transition and the variable outcomes available to a skier from these differing movement patterns speaks to the reasons why versatility requires all three. IMHO
Ric, I very much agree with your versatility philosophy,,, but of course, you already know that. And in fact these 3 transitions only represent a minor portion of the transitions available for use by a broadly skilled skier.

For a highly skilled skier, the length of transition you're seeing is more about skier choice than transition type limitations. I could do any of those transitions, and make the transition very drawn out, or very rapid, depending on my preference. If I'm trying to clearly demonstrate a particular aspect of the movement sequence I may draw it out so the audience has more opportunity to see it. If I'm trying to help a student eliminate a consistent extended dead zone in their transitions, I'll amp up the process to super fast.

And I'm sure you know how this is done, but I'll explain it anyway for those who don't. Speed of a force driven transition is managed by how aggressively pressure is transferred to the new outside foot. In ILE it's how aggressively you push down on the old inside foot. Push down such that 100 percent of pressure is immediately transferred to the old inside foot and the transition will be rapid. Push down such that only a minor portion of pressure is transferred to the old inside foot and the transition can be very slow and drawn out.

Basically the same for OLR, except the manner in which the old outside leg is relaxed is the control mechanism. With either (ILE or OLR), the speed of the transition is not as much about whether the transition being used is Bob 1,2,or 3,,, as it is how fast the skier WANTS IT TO BE. These transitions were obviously done by Bob to demonstrate differences, so I suspect his desire was to take his time in executing them, so as to make them clear to see for the audience. I'm sure Bob has the skill base to alter the speed of these transitions as he sees fit.
Quote:
 RickQuote: Originally Posted by Little Bear All the other frames can be disregarded for the transition question.Ursula Ursula,,, a transition is the sequence of movements that cause one turn to come to an end, and the next to begin. For that entire process to happen, the CM first has to be released from the old turn. Something has to be done to foster that release. It's that initial move which is the origin of a transition, so to accurately discuss a transition that initial movement has to be taken into account. Just focusing on the period in which the CM is crossing over the feet does not do that. It doesn't recognize the initial movement which caused to CM to move towards the neutral point you're focusing on. One must come to understand the entire transitional process if one is going to gain a clear understanding of transitions, and how they vary.
Rick, let me explain my view point a little differently. Let’s take sequence #1 and look at frame 21 (in sequence #2 at frame 9, and in sequence #3 at frame 13). Do you think Bob would have had a chance at these points in his life to change his mind and do something different? (Like lift one foot up, jump, increase the edge angle again and tighten up the radius again or make the actual transition into the next turn 10 yards later, or get radically off the edge to skid, because a barking bear came out of the woods, or ……) If your answer is yes (in my opinion it should be) then it doesn’t matter what moves he did prior to these frames to get to that point. (He had to finish a turn one way or another to get to the point to be able to change edges.) What matters is, that from there on he used the transitions I described earlier.

Ursula
Quote:
 Originally Posted by Little Bear Rick, let me explain my view point a little differently. Let’s take sequence #1 and look at frame 21 (in sequence #2 at frame 9, and in sequence #3 at frame 13).Do you think Bob would have had a chance at these points in his life to change his mind and do something different? (Like lift one foot up, jump, increase the edge angle again and tighten up the radius again or make the actual transition into the next turn 10 yards later, or get radically off the edge to skid, because a barking bear came out of the woods, or ……)If your answer is yes (in my opinion it should be) then it doesn’t matter what moves he did prior to these frames to get to that point. (He had to finish a turn one way or another to get to the point to be able to change edges.) What matters is, that from there on he used the transitions I described earlier.Ursula
Thing is, Ursula, a skier has many options of what to do after the point you're focusing on. They can connect arc to arc, they can pivot entry, they can develop edge angle rapidly, they can drag it out, they can initiate the turn on their inside ski, they can initiate on their outside ski.

If a skier is attempting to accomplish one of these options as a pre-planned intention, and not a last minute change of mind such as you are referring to, then the initial moves the skier makes to initiate their transition can represent an important component in the process of achieving their desired outcome in an efficient manner.
Hi everyone--wow, great discussion! Sorry for my absence. I hadn't meant for this to be a hit and run post, but I also don't want to disrupt this excellent discussion.

Here is another look at the same images, this time somewhat higher resolution (click on each image for the full-size version) and numbered to make discussing them a bit easier.

Sequence #1:

Sequence #2

Sequence #3

For the sake of the discussion, I've placed the frame numbers on the outside of each arc, to help visualize the points of the transitions between turns. In other words, in the first sequence, frames 1-10 represent the first turn to the left; frames 11-24 represent the second turn, and so on. In the second sequence, I think that frames 3 and 11 represent pretty close to the actual moments of transition (edge release, where one turn ends and the next linked turn begins).

Yes, Chris, the time intervals are consistent throughout each sequence, but they vary between sequences. The first sequence shows 6 frames per second. The second and third sequences are at 4 frames per second. You can see that the skiing speed in the second sequence was somewhat less than the other two.

Arghhh! I had a lengthy reponse here, but when I hit "submit" I found it had logged me out and I lost most of it. (Rookie mistake--when will I learn?)

Anyway, I really like the succinct (and accurate) summaries of the flexing extending movements by RicB and Ursula--thanks! It's worth noting, though, that edge release is generally a function of tipping movements, not flexing-extending movements. It is important to keep the flexion-extension and tipping movement pools separate in our minds, and to be able to manipulate them both independently and simultaneously, for different purposes. In other words, you can release or engage edges with or without flexing or extending, and you can flex or extend with or without releasing or engaging. And we need to be able to! That's one of the reasons it is possible to demonstrate such variety of flexing and extending timing through the transitions, and it is why I want to avoid statements like "extend to release" and "flex to release." Both of these expressions imply a causal relationship that doesn't exist, while missing the important causes of "release."

I think that there is more to discuss regarding some of the fore-aft observations and assumptions that have come up in this discussion....

Don't overlook the upper body rotation (and its effects) that shows prominently in the third sequence (as CGeib pointed out--good eye, Chris!).

It would be interesting to discuss now some of the uses (and misuses) of each of these three options. Where and why would you apply one versus the others? What are their effects?

I'll be back with some of my thoughts about the three different turns when I get a chance. In the mean time, keep up the great discussion!

Best regards,
Bob
Can ya all help me understand some of what is happening in these sequences a bit better?

Quote:
 Originally Posted by Rick ...The retracted transition (#2) shows a definite aft turn initiation balance position, and this is typical of retracted arc to arc transitions (see Max's skiing), as there is no pivot to realign fore/aft balance. With arc to arc, the fore recovery has to be accomplished via a manual forward pull. As of the final image, it has not happened.
Quote:
 Originally Posted by borntoski683 I guess in sequence #2, he's floating both skis through the transition in a retraction, which cuts short opportunities to stand on the old outside ski and also delays the opportunity to stand on the new outside ski...ie, creates a longer period of time where both skis are unweighted. While the skis are unweighted, he can't pull himself forward. The only thing I can think of that would possibly help that particular sequence while still retaining the long float period would be to just make darn well sure that before going into float his hips are ahead of his feet. In particular it looks to me that his inside foot could be tucked underneath him just a little bit better before retracting into float. But I suspect, that while trying to amplify a long drawn out retraction turn, it would be very difficult not to find oneself in the backseat coming out of it.
Quote:
 Originally Posted by Rick ...Imagine Bob executing the retracted transition he is, but instead of just hanging in the back seat as CM and skis cross, he uses the back of the ski boots to leverage against to aggressively pull his CM forward at the same time it's moving laterally. That is what needs to be done if one wants to do an arc to arc retracted transition, and not come out of it in a toilet stance, but rather diving onto the front of the ski.
Is Bob really "hanging" on the back of the boots in sequence #2? We're talking about frame 11 that gives this impression, right?

First of all, I look at that position and I know statically standing here on the hardwood floor in my office I can assume dang near that position in my ski boots without falling over backwards. I would possibly be slightly more bent at the waist and possibly have my hands/arms slightly more forward - slightly; however, I also would not be compensating for resistance underfoot, as Bob likely is, that would cause him to move a little aft of where he would appear assuming the same position while stationary. No?

How did he get to that position? ...how are the feet and core interacting as he comes out of that turn - say from frame 7 to 11? As Bob comes out of the control phase of the turn he's sending his core off towards his target in the next turn, right? ...and, at that point his core is ahead of his feet. To get to the other side of the skis from there without deflecting the core off its path to the target creates an issue (with ski boots on) correct? So, the feet need to move forward to allow him to flex at the knee & hip sufficiently to compensate for the restricted ankle movement, right? If the feet are moving forward in relation to the core, isn't the equal and opposite force resistance to the forward movement of the core that would result in a more aft position to stay in balance?

Is Bob really out of balance aft in frame 12? If so, how do we know this? Looks like a nice sunny spring day at Abasin, maybe he flattened those skis in a nice mire of slush and is trying to get off the tongues of the boots he just got slammed against. What evidence in frame 12 indicates the resultant force is aft rather than blowing thru the toe piece of his binding?

As the sequence ends @ frame 12, maybe frame 3 and on is another place to start looking at post transition. To come off of the toilet seat, does Bob really need to aggressively pull himself forward? Is "forward" along the length of the ski? ...or along the path of the core? The core is not really traveling along the length of the ski, but rather crossing the skis, heading across the hill and downhill. Bob is heading downhill and when the core crosses over to the other side of the skis and feet, and is downhill from them, the core is now in front of the feet, right?

How do we know Bob is not "diving onto the front of the ski" in frames 4, 5, ....? Assuming he's not, why does he need to be? What would it gain him?

Quote:
 Originally Posted by Rick ...Also, heavy following of the skis rotationally. OK for arc to arc. Would need to get more rotationally divergent for higher edge angles, for faster transitions and for PET's. I'm guessing these turns were done on quite shapely skis as they allow for these positions.
What are you seeing in sequence #3, Rick? What do you see from frames 2-5 and 11-14? Does the inside hand drop down and back while the outside comes up and forward? Do the shoulders square up (or even turn inside a tad) maybe before transition? I see the inside hand moving forward again by neutral, what stopped and reversed the rotation?

Alright, beat me up! No passport yet, so I've got all summer to learn

Chris
Thanks for the updates with frame numbers, Bob!

Wish ya had been an hour earlier
Quote:
 Originally Posted by cgeib Can ya all help me understand some of what is happening in these sequences a bit better? Is Bob really "hanging" on the back of the boots in sequence #2? We're talking about frame 11 that gives this impression, right?
Actually, Chris, I'm focusing more on where engagement begins,,, 4 and 12

Quote:
 First of all, I look at that position and I know statically standing here on the hardwood floor in my office I can assume dang near that position in my ski boots without falling over backwards.
Not in the position Bob is in you couldn't (4 and 12). Run a vertical line up from the middle of his boot. See how much body mass is behind that line, and how much is in front of it. He's CLEARLY aft balanced.

Quote:
 I also would not be compensating for resistance underfoot, as Bob likely is, that would cause him to move a little aft of where he would appear assuming the same position while stationary. No?
Check out the other sequences, Chris. Compare the vertical line drill results. Same snow, but definately more aft here.

Quote:
 How did he get to that position? ...how are the feet and core interacting as he comes out of that turn - say from frame 7 to 11?
He eventually, as the turn takes place, gets himself forward on his skis. 7-11 is where retraction returns him to aft.

Quote:
 As Bob comes out of the control phase of the turn he's sending his core off towards his target in the next turn, right? ...and, at that point his core is ahead of his feet.
Allowing the core to take a diagonal path in realtion to the skis does not in of itself move the core forward in relation to the feet. In this case, from 7 to 11, the core moves back in relation to the feet as it ventures along that diagonal path.

Quote:
 To get to the other side of the skis from there without deflecting the core off its path to the target creates an issue (with ski boots on) correct? So, the feet need to move forward to allow him to flex at the knee & hip sufficiently to compensate for the restricted ankle movement, right?
If both legs are flexed as it happens, yes, absolutely. This is why his core drops aft in 7 to 11. That's what I've been saying. Extending the new outside leg through the transition helps alleviate that issue.

Quote:
 If the feet are moving forward in relation to the core, isn't the equal and opposite force resistance to the forward movement of the core that would result in a more aft position to stay in balance?
Kind of a stretch, but perhaps, momentarily. But once the relationship change is done, things stabilize, and the same situation exists,,, the skier is aft.

Quote:
 Is Bob really out of balance aft in frame 12? If so, how do we know this?
Yes. Do the vertical line drill. This is not even close to debatable.

Quote:
 Looks like a nice sunny spring day at Abasin, maybe he flattened those skis in a nice mire of slush and is trying to get off the tongues of the boots he just got slammed against. What evidence in frame 12 indicates the resultant force is aft rather than blowing thru the toe piece of his binding?
Come on, Chris, you're trying way to hard, and for no reason. Aft is not necessarily a bad thing if it's ones intent. If your above attempt to claim Bob was actually center balanced had any validity, then he would be doing forward rolls in the other 2 sequences because he would be WAAAAAAY to far forward. Same day, same snow,,, think about it.

Quote:
 As the sequence ends @ frame 12, maybe frame 3 and on is another place to start looking at post transition. To come off of the toilet seat, does Bob really need to aggressively pull himself forward?
If he wants to get fore earlier in the turn, yes. Looking from 3 on it can be seen that Bob initiates the turn aft, then eventually catches up to centered. I'd say by about the apex.

Quote:
 Is "forward" along the length of the ski? ...or along the path of the core?
Balance is an ever changing (dynamic) state. It must be measured as a moment in time,,, core to feet.

Quote:
 The core is not really traveling along the length of the ski, but rather crossing the skis,
True,,, but at any particular moment, it does have a fore/aft relationship with the feet. As that relationship changes, so does fore/aft balance.

Quote:
 heading across the hill and downhill. Bob is heading downhill and when the core crosses over to the other side of the skis and feet, and is downhill from them, the core is now in front of the feet, right?
Chris, this only works when combined with a pivot. If the skis remain on the same course of travel, the CM being on the uphill or downhill side of them makes no difference in regard to fore/aft balance.

Quote:
 How do we know Bob is not "diving onto the front of the ski" in frames 4, 5, ....? Assuming he's not, why does he need to be? What would it gain him?
From 4 to 5 he IS in the process of moving fore. Look at his outside leg,,, it's extending. This is pulling his hips forward.
The higher resolution images have revealed a formerly hidden "Bob-2" in sequence #1, changing my (and perhaps others) stated Bob-number.

The higher resolution has also erased my perceived 'lifted Inside ski' in sequence #3, frames 5 and 14.

Still, to keep it interesting as a Good Contrarian I'll cling scandalously to the possibility that Bob could have skied these 'Alternate CM-Path' demos with some modicum of differing Inside/Outside Ski-pressure bias. (Whether he did or not is another matter )

.ma
Quote:
 Originally Posted by cgeib As the sequence ends @ frame 12, maybe frame 3 and on is another place to start looking at post transition. To come off of the toilet seat, does Bob really need to aggressively pull himself forward? Is "forward" along the length of the ski? ...or along the path of the core? The core is not really traveling along the length of the ski, but rather crossing the skis, heading across the hill and downhill. Bob is heading downhill and when the core crosses over to the other side of the skis and feet, and is downhill from them, the core is now in front of the feet, right? Chris

Just found this thread and it is the kind that make this site a jewel. Bob's skill with visuals and context, initiates the great conversations above and create excitement for me to want to go skiing! Thanks bob!

Chris, I know you intended for a response from someone other than me but.... I think your observation of the aforementions sequences is very accurate. I think Bob is making full use of the fore/aft plane and the energy stored in the ski to load the tails to aid edge grip and end the previous turn then springboarding along the path of core across the skis to apply the appropriate load to the shovels in the new turn. This is a very solid feeling and makes maximum use of the skis' design while insuring solid edge grip.

Ursula....I just keep gaining more and more respect for your talents!!

When I looked at the three turns I thought of a centerline and two polar movements on either side. The more traditional transition, labeled by Ursula as "extending both legs" seems a bit dated by today's skiing and seems kinda passive and slow to transition. The "flexing both legs" at transition seems more efficient when absorbing forces in excess of what is needed during transition, whether it be dynamic turns or bumps. It is more condusive to "high C" turns and moving the pressure higher in the turn arc. While the "centerline" transition to me is the "flex one while extending the other" which is somewhere in the middle of the spectrum of movements demonstrated. Any of these three transitions when done in balance put the skier in a good position from which to maximize their options for quick changes in line or tactic while passing through "neutral".

To me, how quickly the skier wants to transition, would seem to be one of the main factors in choosing which transition is used? Looking closely at the distance traveled during the transitions (from equal edge angle to equal edge angle) would seem to bear this out. A pendulum takes longer than a straight line...

bud
Quote:
 Originally Posted by bud heishman I think Bob is making full use of the fore/aft plane and the energy stored in the ski to load the tails to aid edge grip and end the previous turn then springboarding along the path of core across the skis to apply the appropriate load to the shovels in the new turn.
And we've now just entered the twilight zone. :
Quote:
 Originally Posted by Rick Allowing the core to take a diagonal path in realtion to the skis does not in of itself move the core forward in relation to the feet.
Hmmmm... I'll probably need to get my Nomex Bunny Slippers out for this but for some cases I'll disagree on this statement. I'll further suggest that in particular, the statement…
Quote:
 Originally Posted by Rick Balance is an ever changing (dynamic) state. It must be measured as a moment in time,,, core to feet
…specifies a Particular Context that tends to muddy-up an accurate analysis of moving bodies if not done precisely.

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First, there is the issue of *Ballistics* to consider. While we can guess that Bob’s upper-body Mass is moving across his skis at a given rate (diagonally) we also need to look at the rate his body Mass is traveling horizontally and vertically. If his Upper-Body continues “outward” (away from the slope and dropping away from him) - it will not be exerting any (or not much) force downward onto his skis even though it may be accelerating downward. If his butt is way back - but not exerting any force downward onto his skis - is he really “Out of Balance?”

And if his skis continue arcing forward (a rotational thing) while his Upper-Body travels a ballistic (though directionally-straight) path… his Upper-Body can end up facing downhill when his skis end up pointed downhill and what was a ‘backseat’ position has transformed into a ‘lateral’ position for his Upper-Body.

While he may have had the appearance of being in the backseat, his Fore/Aft balance may never have been compromised to any meaningful degree before everything Rotates into a new, in-balance relationship.

Getting back to Rick’s desire to measure things at a precise moment in time - we can still do this but the measurement must take such ballistics into consideration.

We generally miss the point that our skier’s Mass may be Falling or Dropping and/or that the skis may be Falling or Dropping away from the skier. Is the skier’s CM aligned directly over their feet? Maybe not - but does this matter if no “support” of the CM is required in those moments of mis-alignment?

Also, it shouldn’t matter whether our skier is doing a pivot or a carved turn. All that matters is the timing of proper alignment (between the CM and the Base-of-Support) when that support is actually required. A properly aimed CM following a ballistic path can effectively be launched from the old turn into a re-balanced alignment somewhere in the new turn.

If the skier allows their skis to edge and become pressured strictly by centripetal force then only that component is involved - and that force tends to push the skis back under our skier if their Upper-Body has traveled to the correct location!

In short, to be meaningful to structural alignment (and balance) our 'Moment-in-Time' Force-Vector diagram needs to be modified to represent the degree to which our skier is 'falling' - not just show the magnitude of Gravity.

.ma
I'm just amazed by the absurd lengths you guys are going to to contend that someone sitting on his tails is loading his tips. What baffles me even more is why. I swear, if you folks really can't recognize 4 and 12 as aft, God help the people you try to teach to ski.
Quote:
 For a highly skilled skier, the length of transition you're seeing is more about skier choice than transition type limitations. I could do any of those transitions, and make the transition very drawn out, or very rapid, depending on my preference.
I agree Rick, there is an intentional deliberateness to his skiing. However for general discussion, I don't think that these three transitions are all equal in speed with respect to moving from turn to turn, and I can certainly see differences in our ability to tip into the turn and quickly develope edge angles.

For me I think it is fair to say that these three turn transitions represent a sensible broad spectrum available to skiers. Not to say that within these three there are not infinite blends and variations to be utilized by the skiing public. Nothing is absolute or completely definitive.

It will be interesting to see where Bob takes this. Rick it is always a pleasure and a learning opportunity to exchange ideas with you.
Thanks Bob. You are right that I didn't give tipping movements their due. They were very much in my head, but I only alluded to them in the context of how the flexion and extension movements related to tipping availability.
Quote:
 Originally Posted by Rick And we've now just entered the twilight zone. :
Did I say something wrong? Let me rephrase...

I agree with MichaelA in that, though a still photo may show the alignment of sitting back by Ricks definition it may be a moment where different paths and axis' are realigning and there is no imbalance.

Going back to the three different transitions. I believe that to make a quicker transition we need to flex, or be flexing at the edge change to facilitate a more rapid straight path of the cm vs. a slower pendulum type movement across the skis. Now, it would seem the more aggressively we do this the more a position like Bob's would appear because as we release the pressure or energy from one turn and move across the skis, the skis/feet will want to naturally move forward. At this point the skis may be EVENLY weighted OR unweighted fore/aft but the appearance in a still image, as evidenced above, may be back seat. I do not see Bob's tails bending in the photo Rick eludes to?

Now if Bob wanted to make this move even more dynamic or if he were to get squirted a bit too far, he could then, as I stated earlier, "springboard" forward off the tails to catch up. Having a stiff boot cuff and ski tail make this much easier. How many racers do you know of who ski in soft rearward flexing boots and soft tailed skis???? Wonder why?

Savy?

bud
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