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Thread: Divergence discussion

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    I have my own seat in the pub Skier Village Coach Coach Rick's Avatar
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    Divergence discussion

    Check out the 2 photos below. They display something called divergence, which happens at the start of turns very commonly, both in WC racing, and on the public trails. Divergence is having the tails of the skis closer together than the tips, such that the skis are in a reverse wedge position.

    Care to have a go at why it's taking place? What it's accomplishing, and the benefits provided by it? Hint, before you think this a trick question, divergence is not necessarily wrong, or a mistake.


    Name:  Bode,Divergence,Web.jpg
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    Name:  Ligety,Divergence,Web.jpg
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    I'm seeing a difference in ankle extension (plantar flexion) in the outside foot so that makes me consider why. The next clue is the lifted tip in the first. The one I base my conclusion on is the angle of the skier to the stick. In the first he is getting off of his outside foot near his apex and using the centripetal force he has gathered. The divergence is caused by an open ankle to the end on his outside foot and foot to foot movement .

    The second I think he got caught late in less efficient timing and needed to make a path correction. His outside ankle appears flexed (dorsiflexion) If he continues he can easily (for him)have his mass crossover his feet in a good place. I think momentum will cause him to be on the outside ski soon enough but long in the turn so what does do to create a convergence ? A step, skid the outside over, or come together later with the finish ? Do you have more of this sequence ? Also for all we know maybe he lost edge when he decambered his outside ski for whatever reason and recovered to aim his inside leg to make the most of it.


    Nice tactical skiing, one displaying power and finesse and the next displaying athleticism and balance.
    Both are caused by intent to achieve a desired outcome.
    Last edited by garryz; March 16th, 2014 at 08:24 PM.

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    Moderator Snow Sport InstructorSkier Village Coach LiquidFeet's Avatar
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    Bode and Ted are "leading the turn" with that new inside ski. They have sucked the new inside leg up, and toppled across it into the inside of the current turn. They are lightening that inside ski and turning it dramatically while they ride the bent carving outside ski. Bode's even got his inside ski tip up in the air. Ted's inside ski has its tail gouging into the snow, sending out spray. Both are riding the outside ski to make the turn.

    They are lifting/lightening the inside ski to get it out of the way; they are disengaging it temporarily. They are manually turning it since it needs to turn tighter than the outside ski. It won't be able to do that on snow from bending because they don't want it weighted enough to bend tighter than the outside ski. They need all their weight on that outside ski so it will bend as much as possible and keep them on the line they have chosen without letting go of its carve. Once the sharp part of the turn is done they will press down on the little toe edge of that inside ski to start the next turn. It's just out of the way now.

    Both are holding that inside foot back, waiting for the outside ski to come around. I think that the holding of the foot back while tipping it to the little toe edge contributes to the divergence, and also causes the tip to be lighter than the tail. It's faster doing the turn that way; I can't explain it but I can "feel" it sitting here and imagining doing those turns (which admittedly I cannot do).

    If you put a paddle straight down in the water on one side of a canoe or kayak while gliding straight ahead, the paddle will cause the boat will turn around it. That tail gouging the snow in Ted's turn is probably helping him tighten his turn, the same way a vertical paddle held in the water will cause the canoe to turn. The little toe edge of the tail pressed into the snow with the tip lightened may be intentional for both of them.
    Last edited by LiquidFeet; March 17th, 2014 at 09:35 AM.

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    Home Sweet Home Skier Village Coach mastersracer's Avatar
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    I would like to see more pictures. A snapshot of a WC turn is exciting, but it doesn't tell us anything about the dynamics of the turn. Why are they in that particular location? What did they do to get there?

    The inside ski is light in Bode's turn because he is making a powerful, turn on his outside ski. When the inside ski is as light as it is in these turns, it doesn't matter that much which way it is pointing. Ligety's looks like he may be finishing a stivot on the inside ski, preparing to engage the outside ski. Ligety's left ski isn't fully engaged and is still pointing outside whereas Bode's is nearly, if not fully, engaged and pointing down the fall line.

    In a nutshell, one is on their inside ski, the other on their outside. They are diverging because they aren't both engaged.

    My guess as to the answers to my questions: Bode started his edging way before Ted and is putting all his weight on his outside ski, Ted is finishing one move on his inside ski in anticipation of pressuring and arcing the outside one.

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    I have my own seat in the pub Skier Village Coach Coach Rick's Avatar
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    Quote Originally Posted by mastersracer View Post
    I would like to see more pictures. A snapshot of a WC turn is exciting, but it doesn't tell us anything about the dynamics of the turn.
    Here, MR, perhaps this will help. It's a montage of Ted in the same turn.


    Name:  Ligety,Montage,Web.jpg
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    Ted actually won this run, and the race, and was one of the only racers to ski that turn arc to arc. Most everyone else pivoted it. We have video of that turn too, in which you can see the arc to arc very clearly, and the contrast to the other racers.
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    Quote Originally Posted by LiquidFeet View Post

    They are lifting/lightening the inside ski to get it out of the way; they are disengaging it temporarily. They are manually turning it since it needs to turn tighter than the outside ski. It won't be able to do that on snow from bending because they don't want it weighted enough to bend tighter than the outside ski. They need all their weight on that outside ski so it will bend as much as possible and keep them on the line they have chosen without letting go of its carve. Once the sharp part of the turn is done they will press down on the little toe edge of that inside ski to start the next turn. It's just out of the way now.
    LF, well thought out. This paragraph or yours really zeros in on the answer.

    Yes, just as you say, that inside ski needs to get out of the way somehow. Trying to carve it while keeping it parallel with the outside ski requires it to carve a smaller radius arc than the outside ski, as you correctly stated. That would require tipping it higher on edge then the outside ski, which would be anatomically cumbersome to say the least, and/or assigning more weight to it than is advisable, as you also rightly pointed out. Somehow the skier needs to compensate for the inability to carve both skis arc to arc in a parallel relationship through the entirety of the turn. Divergence instantly increases the turn radius ("increase" meaning a less sharp turn) the inside ski must execute to carve cleanly through the entire turn in harmony with the outside ski. With the use of divergence they can carve both skis, even though the inside ski is on a lower edge angle and has less pressure. Simple solution, right?

    We can see in the montage I just posted how the whole thing plays out. Ted intentionally diverges his inside ski at the start of the turn, but because it's not carving as sharp a turn as the higher angled and more strongly pressured outside ski, that divergence naturally goes away by the turn's apex (image 5), then morphs into convergence through the bottom of the turn. Just as you would expect would happen.

    If divergence was not used some other means would have be used to keep the skis turning in harmony through the turn. Carving would not work, the skis would come together and cross before the end of the turn. Enter the manual turning option you mentioned, LF. Just add some rotational tension to the inside leg, and let that power steer it through the turn, such that it stays parallel to the carving outside ski. The problem with that is; steering means skidding, which is slow. Doing something that will allow the inside ski to carve will be faster.

    That make sense, everybody?

    There's another benefit to this divergence thing. What happens when skis diverge? If they're carving do they track further apart? Is that a good thing? Why?
    Last edited by Coach Rick; March 17th, 2014 at 11:30 PM.
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    I have my own seat in the pub Skier Village Coach Coach Rick's Avatar
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    Quote Originally Posted by garryz View Post
    I'm seeing a difference in ankle extension (plantar flexion) in the outside foot so that makes me consider why. The next clue is the lifted tip in the first. The one I base my conclusion on is the angle of the skier to the stick. In the first he is getting off of his outside foot near his apex and using the centripetal force he has gathered. The divergence is caused by an open ankle to the end on his outside foot and foot to foot movement .

    The second I think he got caught late in less efficient timing and needed to make a path correction. His outside ankle appears flexed (dorsiflexion) If he continues he can easily (for him)have his mass crossover his feet in a good place. I think momentum will cause him to be on the outside ski soon enough but long in the turn so what does do to create a convergence ? A step, skid the outside over, or come together later with the finish ? Do you have more of this sequence ? Also for all we know maybe he lost edge when he decambered his outside ski for whatever reason and recovered to aim his inside leg to make the most of it.


    Nice tactical skiing, one displaying power and finesse and the next displaying athleticism and balance.
    Both are caused by intent to achieve a desired outcome.
    Thanks for jumping into the discussion, GZ. I posted the extra photos you requested a couple posts ago. The montage provides a better picture of the quality of the entire turn. Ted really nailed this one, blew the rest of the field away in it. Everyone else was pivoting, and skidding. Ted just rolled on edge, arc to arc, and ripped through it clean as a whistle.

    Consider this; if you wanted to diverge your inside ski, would you want to get the tip up off the snow a bit to do it, so it wouldn't hang up or drag? Back in the day we did this same divergence move, but we did it at the end of the turn, in coordination with a powerful direction changing step. We always lifted the inside ski or tip to execute that tactic.
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    When ever you intend to move from one foot to the other into a turn it's important to get the inside ski moving first as evidenced by the first photo. In steeps or uneven terrain where air is anticipated getting the inside foot moving is critical.
    In your more complete montage you can see him steering the inside foot on a lessor edge. The divergence has begun at that point.

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    Just lifting and moving the inside ski because of differing turn radii does not tell the whole story. The pelvis is rotated into the turn with a skating move to anticipate the reaction of checking the gate on the center of mass movement. Anyone whom has ever checked a gate knows that there is quite a bit of destabilizing force from checking a gate. It's all about dynamic balance. Checking the gate rotates the pelvis back to towards the outside of the turn and into the perfect power position. The diverged ski is then parallel to the outside ski.

    The only sport with voluntary caning.

    Years of competition hone this skill until it becomes second nature.

  10. #10
    Moderator Snow Sport InstructorSkier Village Coach LiquidFeet's Avatar
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    Hey Pierre. How's the ski season going?

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