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# Groomed turn- MA - Page 4

I think you may have read way more into those images than what was intended, SD. The lines simply highlight the lateral angle of the shin, and the angle of the edge (or at least, of the base of the ski). They do not represent force vectors or anything of the sort, and the actual locations of the lines are somewhat arbitrary, drawn where they are--shin centerline, and along the base of the ski--simply because that seemed the easiest place to identify the respective angles. Your red line, on the other hand, while it may approximate a relevant force vector, does not appear to represent the lateral angle of the shin that I have tried to illustrate.

Regarding whether he would fall over or not with the leg movement I've drawn, that would depend entirely upon how fast he is going, the radius of the turn, how much pressure ("balance") he sustains on that inside foot, and what other compensating movements he might or might not make with his arms and upper body. I suspect that, all else being equal--and in particular given the relatively low outside ski edge angle that would both tend to elongate the turn radius if carving, and minimize the outside ski's grip (edge hold), making carving unlikely, that you just might be right. But with proper alignment and other adjustments, all else would most certainly not be equal!

Best regards,
Bob

Edit--ahh, I see that you have added another image while I was composing this post. The red lines on the final (largest) frame would appear to support the misalignment argument, as they illustrate the angle the shin would need to be if it were to form a 90 degree angle to the ski base. The lines on the first frame may be relevant too, but the camera angle there makes it even more difficult to accurately estimate "lateral shin angle." Nevertheless, if you are correct that the shin and ski form more closely a right angle in that frame where the ski has minimal pressure on it, but an acute angle in the final frame where the ski is highly pressured, it supports the thought that he may have a lot of slop and play in his binding/boot interface. With wide skis on harder snow, pressure on the edge applies substantial torque which tends to fight against the skier's efforts to tip the ski on edge. Worn boot soles, play in the bindings, or even too loose or too laterally soft boot cuffs will make the problem worse--and any of these could be happening in this photo-sequence. On the other hand, the fact that the inside ski also appears to show a similar "underedged" alignment--even with some pressure on the little toe edge--does not support the "loose connection" possibility.

All of these things would be worth investigating, Alex.

Best,
Bob
Quote:
Originally Posted by Bob Barnes

I think you may have read way more into those images than what was intended, SD. The lines simply highlight the lateral angle of the shin, and the angle of the edge (or at least, of the base of the ski). They do not represent force vectors or anything of the sort, and the actual locations of the lines are somewhat arbitrary, drawn where they are--shin centerline, and along the base of the ski--simply because that seemed the easiest place to identify the respective angles. Your red line, on the other hand, while it may approximate a relevant force vector, does not appear to represent the lateral angle of the shin that I have tried to illustrate.

I know what you were trying to show.  You were tryiing to make the case his alignment is out.  But alignment is not about making the shin bone 90 degrees to the ski base.  Its about aligning the body so it can efficiently handle the forces placed on it.   My lines tried to depict that.  So yes by default they do approximate the aligment of the force vector as well..but that wasnt what I was showing.

(Having said that...I acknowledge with camera angles etc is pretty darn near impossible to determine alignment issues which are measured in 1 or 2 degrees with this method, and I am not suggesting that my lines prove his alignment is perfect (it likley isnt), but I do think it makes the case, that the skier in question has aligment that is close enough, that he can in fact get alot more performance then what he is by changing technque.  As I wrote earlier,,, alignment might get him another 5%...technique will get him 50%.  I dont believe this is a case where his alignment is so bad, that he simply cant make big gains without getting more boot work.)

Quote:
Originally Posted by Bob Barnes

Regarding whether he would fall over or not with the leg movement I've drawn, that would depend entirely upon how fast he is going, the radius of the turn, how much pressure ("balance") he sustains on that inside foot, and what other compensating movements he might or might not make with his arms and upper body. I suspect that, all else being equal--and in particular given the relatively low outside ski edge angle that would both tend to elongate the turn radius if carving, and minimize the outside ski's grip (edge hold), making carving unlikely, that you just might be right. But with proper alignment and other adjustments, all else would most certainly not be equal!

Best regards,
Bob

Well, I agree with you here.  No doubt that inside leg is in the wrong spot...in frame 3, but to me that is a symptom.....not the problem,  Based on my assessment that he is simply "banking", the race coach advice to me would be to:

"lead the turn with the inside knee:....(ie start the tip with the little toe edge of the inside ski)...I believe PMTS calls this the "Phantom Move".  I think it is reasonable advice here, as it would slow down his rate of inclination, thus making him balanced over the outside ski, which would then enable him to work inside more effectivley, thus eliminating that A-frame we see in 3.

Just a short question to the big dogs in here. Besides fore/aft balance isn't there a horizontal balance plane? Working the pressure back and forth between the 2 skis. Tipping the inside ski and countering towards the outside ski. Thanks.

Quote:
Originally Posted by Skidude72

I know what you were trying to show.  You were tryiing to make the case his alignment is out.  But alignment is not about making the shin bone 90 degrees to the ski base.  Its about aligning the body so it can efficiently handle the forces placed on it.   My lines tried to depict that.  So yes by default they do approximate the aligment of the force vector as well..but that wasnt what I was showing.

(Having said that...I acknowledge with camera angles etc is pretty darn near impossible to determine alignment issues which are measured in 1 or 2 degrees with this method, and I am not suggesting that my lines prove his alignment is perfect (it likley isnt), but I do think it makes the case, that the skier in question has aligment that is close enough, that he can in fact get alot more performance then what he is by changing technque.  As I wrote earlier,,, alignment might get him another 5%...technique will get him 50%.  I dont believe this is a case where his alignment is so bad, that he simply cant make big gains without getting more boot work.)

Well, I agree with you here.  No doubt that inside leg is in the wrong spot...in frame 3, but to me that is a symptom.....not the problem,  Based on my assessment that he is simply "banking", the race coach advice to me would be to:

"lead the turn with the inside knee:....(ie start the tip with the little toe edge of the inside ski)...I believe PMTS calls this the "Phantom Move".  I think it is reasonable advice here, as it would slow down his rate of inclination, thus making him balanced over the outside ski, which would then enable him to work inside more effectivley, thus eliminating that A-frame we see in 3.

I think that part of what we are seeing relates directly to what Alex said in his initial post....  That he is working on getting early edge angles.  I suspect that this desire to create early edge angles leads him to move inside very fast and is leading to the banking ie inclination without agulation.

Is there a simple on snow exercise (like single ski gliding) to check or provide a hint on canting correctness? If there is, Alex can just try it.  I paid the boot fitter a small fee to ski with me before I have my boot aligned. He let me try on different shims on snow and did different exercises to find the correct one. I let him cant my boots only after I see clear improvement. I will not have a boot fitter cant my boots without going thru this process again.

Edited by hellside - 4/10/13 at 12:58pm

I agree with this. But is that not going to very difficult with the torso,  shoulders and hands rotated in the wrong direction

Quote:
Originally Posted by Skidude72

I know what you were trying to show.  You were tryiing to make the case his alignment is out.  But alignment is not about making the shin bone 90 degrees to the ski base.  Its about aligning the body so it can efficiently handle the forces placed on it.   My lines tried to depict that.  So yes by default they do approximate the aligment of the force vector as well..but that wasnt what I was showing.

(Having said that...I acknowledge with camera angles etc is pretty darn near impossible to determine alignment issues which are measured in 1 or 2 degrees with this method, and I am not suggesting that my lines prove his alignment is perfect (it likley isnt), but I do think it makes the case, that the skier in question has aligment that is close enough, that he can in fact get alot more performance then what he is by changing technque.  As I wrote earlier,,, alignment might get him another 5%...technique will get him 50%.  I dont believe this is a case where his alignment is so bad, that he simply cant make big gains without getting more boot work.)

Well, I agree with you here.  No doubt that inside leg is in the wrong spot...in frame 3, but to me that is a symptom.....not the problem,  Based on my assessment that he is simply "banking", the race coach advice to me would be to:

"lead the turn with the inside knee:....(ie start the tip with the little toe edge of the inside ski)...I believe PMTS calls this the "Phantom Move".  I think it is reasonable advice here, as it would slow down his rate of inclination, thus making him balanced over the outside ski, which would then enable him to work inside more effectivley, thus eliminating that A-frame we see in 3.

Quote:
Originally Posted by tetonpwdrjunkie

A skier with a "strong inside half" leads the turn with the inside of the body.  In this position the inside hand is forward and above the outside hand.  If a pole was to be laid across the hands, that pole should be roughly parallel to the slope angle.  This parallel relationship would ideally be mirrored in the feet, knees, hips shoulders, and eyeballs as well as the hands.  The other relationship we are optimally looking for is that the tip lead is mirrored by the knees, hips, shoulders, eyeballs and hands.  For years I focused mostly on keeping the inside hand forward where I could see it.  Changing my focus to keeping the outside hand back helped with keeping the inside hand forward and did put me into a stronger balanced position.  My "problem" has been a tendency to drive the outside hand forward into the turn completion which leads to an over rotation of the upper body at the end of the turn and has inhibited my ability to angulate and separate my upper and lower halves....

Quote:
Originally Posted by tetonpwdrjunkie

I shifted my focus from the inside to the outside hand after a clinic mid season and found that keeping the outside hand back and down relative to the inside hand worked better for me.  It's important that when you begin to swing your pole with the outside hand that your body moves with it directionally down the hill.  This will help dial back the upper body rotation at the end of the turn.  At least it did for me.

Me too, TPJ.  I watch skiers at Cannon, many of them strong skiers, doing that thing with their old outside hand as they are about to plant the pole.  It is quite common.  They swing that hand forward and around in front of their torsos, in front of their direction of travel, pulling their old outside hip forward along with the hand.  Then they swing it out to plant the pole.  This 1-2 move produces a slight but unfortunate outside hip rotation forward at the end of the turn.   I was told I was "settling" into my turns; "settling" was linked by one trainer to this hip rotation.

I too have focused on holding that old outside hand back this season to eliminate the hip rotation and the "settling."  What a great difference it's made.  The old outside hip stays back along with the hand, so the dysfunctional stuff is gone.  Sometimes I focus on the hip, and the hand follows along.  Both work ... for me.

People are different; what works for some may produce bad results for others.

I am not sure keeping it back is really the key, as you shoud be planting or at least using a pole touch to help set up the next turn and draw you down the hill.

I think the key is where you pole touch. Many pole touch too far forward. I contend your outside hand should be reaching down the hill. The steeper the pitch the more straight down from your boot (or the farther back you plant.

that crazy rotation where the outside hand even crosses .past mid body and sometimes tI see skiers really exaggerate this and swing the arm completely across their body as a move to a pole touch. completely counter rotates you to the direction of travel. If you were attempting to make a right footed turn to the left it turns your upper body uphill to the right when you are trying to travel to the left.

Alexn has a bit of this going on it looks like , not as extreme as I just described but it is still there. Really difficult to turn downhill when your upper body is facing uphill!

Yeah, but it's a really stylin' pole plant...

I have it too and it's a hard habit to break.

Quote:
Originally Posted by Atomicman

I am not sure keeping it back is really the key, as you shoud be planting or at least using a pole touch to help set up the next turn and draw you down the hill.

I think the key is where you pole touch. Many pole touch too far forward. I contend your outside hand should be reaching down the hill. The steeper the pitch the more straight down from your boot (or the farther back you plant.

that crazy rotation where the outside hand even crosses .past mid body and sometimes tI see skiers really exaggerate this and swing the arm completely across their body as a move to a pole touch. completely counter rotates you to the direction of travel. If you were attempting to make a right footed turn to the left it turns your upper body uphill to the right when you are trying to travel to the left.

Alexn has a bit of this going on it looks like , not as extreme as I just described but it is still there. Really difficult to turn downhill when your upper body is facing uphill!

I disagree.  The pole swing is far more important than the actual touch.  The swing can't move in the proper direction if the hand isn't in the right place, hence the need to hold the outside hand back if you have a natural tendency to over rotate and drive the hand around as I do.  I also contend that reaching down the hill is a counter productive move.  The movement I want is from the wrist only. I don't reach down the hill with my arm, I swing the pole in that direction using my wrist and the pole touch is an outcome of my body following the pole and tipping down the hill.  I don't put the pole down, the body moves/tips down and the pole touches.  I can show you lots of examples where skiers who reach down the hill with their arm bend at the waist while doing this moving their butt and their hips up the hill.  This is of course the oppisite of what we are trying to achieve with a pole swing/touch.  The direction of the pole swing and the move across the skis should be in the direction of the turn.  Where the pole touches, forward or down the hill will depend on where the skis are facing relative to the fall line when the old turn ends and the intended size of the next turn.

I think we would agree on snow and you aren't getting the correct mental picture.  The outside hand is back relative to the inside hand when viewed in the sagital plane.  Both hands are forward relative to the upper body which is facing what many would call downhill and I would say should be more accurately described as towards the apex of the next turn.

Quote:
Originally Posted by slider

Just a short question to the big dogs in here. Besides fore/aft balance isn't there a horizontal balance plane? Working the pressure back and forth between the 2 skis. Tipping the inside ski and countering towards the outside ski. Thanks.

you could  argue there is fore and aft,  lateral an rotational..... that how I think of it at least.

Quote:
Originally Posted by Atomicman

I agree with this. But is that not going to very difficult with the torso,  shoulders and hands rotated in the wrong direction

It would be yes....almost impossible I think.  Hence my advice.

Intiate turns with the inside knee/ankle/pinky toe (or any method he likes to prevent him from coming in too quick (I like keep the shoulders level, works great also)......ie at frame 3 in the OP monatge...this if achieved should result less inclined at 4, and balanced over the outside foot (hopefullly), thus he can continue working inside throught frames 5 and 6....and thus not get bent out of shape from trying so hard to  "pull the turn".

Having said that, if Bob is right, that there is "slop" between the boot/binding interface....he needs to fix that first.

If there can really be that much leg-boot-binding-ski slop, it would explain why some people think you can't carve on fat skis.

Quote:
Originally Posted by mdf

If there can really be that much leg-boot-binding-ski slop, it would explain why some people think you can't carve on fat skis.

it why cheap bindings suck as do touring binding...

The pole planting has a lot to do with the radius of turn. If we ski with a shorter radius it will typically be more of a down the fall line, emphatic plant (not TOO emphatic). A longer radius plant (if there is one ) will be more in the direction we are travelling (more across the fall line) and gentler. Pole plants, IMO, compliment the amount of counter we are employing and should not cross the centerline in any case (though photographic images of world cuppers could be found). Generally little rotary movement of the arm itself is desired as the shoulder (and possibly pelvis) can follow suit, although I feel a movement from down by the knee up and "forward' works fine for larger radius. Wrist in a short radius will be more open to encourage "open" shoulders, large radius, less so.

zenny

Edited by zentune - 4/10/13 at 7:28pm
Quote:
Originally Posted by mdf

If there can really be that much leg-boot-binding-ski slop, it would explain why some people think you can't carve on fat skis.

Yes, and it is also why people think that fat skis have bad ice grip.

Quote:
Originally Posted by Jamt

Yes, and it is also why people think that fat skis have bad ice grip.

Fat  skis do have bad ice grip.....relative to a narrow ski of comparible torsional ridigity.

I am following the discussion, fascinating, I appreciate all the comments.  You guys picked up the hand-pole-plant swing!  Another bad habit I am trying to break.   Quick note about boot-binding slop:  The boots had half a season on them at the time, bindings were new Salomon demo bindings.  I personally checked the forward pressure, it was fine.  If there was any slop I would have felt it, and I would not have been able to ski a lot of stuff that I skied that day.  Here is the POV from off-piste runs on that day (I know the POV has just about zero value for MA, but there are shadows and hopefully that could convince you about the absence of boot-binding slop).  This video has been posted in the Tahoe conditions thread, so I apologize for the repeat.

Quote:
Originally Posted by Skidude72

Fat  skis do have bad ice grip.....relative to a narrow ski of comparible torsional ridigity.

Yeah, my statement was a bit oversimplified. To get good icegrip you need to penetrate the surface. You can get that by having a shorter contact surface. That is why a rockered, longitudinally soft ski can have excellent ice grip. If you have a ski with über-rocker and sloppy ends you pretty much have a off-center ice skates. Use some soft rotary boots and throw on a freeride binding that gives a few degree and that is no longer true.

You can also shorten the contact surface by bending the ski, e.g. leverage of the boot cuffs. This moves the contact area forward and that is one reason why torsional rigidity becomes important.

Torsional rigidity also plays a role because the entry platform angle will be more advantageous. Off course a racing ski will always be better, but IMO some fat skis have better ice grip than many think if you just put on a stiff binding. A race binding is pretty much the only type that does not give (well it also gives but not so much).

Its funny, people can spend a significant amount of money to adjust the boots to 0.1 degrees of accuracy in canting/cuff, and then they slap on a pair of bindings that give a few degrees. No alignment will solve that. Good thing that Bud changed his concept from TAPP to TEPP.

Quote:
Originally Posted by Jamt

Yeah, my statement was a bit oversimplified. To get good icegrip you need to penetrate the surface. You can get that by having a shorter contact surface. That is why a rockered, longitudinally soft ski can have excellent ice grip. If you have a ski with über-rocker and sloppy ends you pretty much have a off-center ice skates. Use some soft rotary boots and throw on a freeride binding that gives a few degree and that is no longer true.

You can also shorten the contact surface by bending the ski, e.g. leverage of the boot cuffs. This moves the contact area forward and that is one reason why torsional rigidity becomes important.

Torsional rigidity also plays a role because the entry platform angle will be more advantageous. Off course a racing ski will always be better, but IMO some fat skis have better ice grip than many think if you just put on a stiff binding. A race binding is pretty much the only type that does not give (well it also gives but not so much).

Its funny, people can spend a significant amount of money to adjust the boots to 0.1 degrees of accuracy in canting/cuff, and then they slap on a pair of bindings that give a few degrees. No alignment will solve that. Good thing that Bud changed his concept from TAPP to TEPP.

Pardon my ignorance here, Jamt. I've never been on a fully rockered ski (they're kind of ugly looking to me), but doesn't the fact that they have "sloppy ends" especially at the tip make applying pressure to the forebody more difficult to achieve at the top of the turn and therefore decrease our ability to get early turn shape going? Not to mention how slow edge to edge they are. That would seem to make carving on ice less effective...or is it more about patience with these skis, ie much larger radius turns?

zenny

Quote:
Originally Posted by zentune

Pardon my ignorance here, Jamt. I've never been on a fully rockered ski (they're kind of ugly looking to me), but doesn't the fact that they have "sloppy ends" especially at the tip make applying pressure to the forebody more difficult to achieve at the top of the turn and therefore decrease our ability to get early turn shape going? Not to mention how slow edge to edge they are. That would seem to make carving on ice less effective...or is it more about patience with these skis, ie much larger radius turns?

zenny

Absolutely, pressuring the forebody on rockers is not a good idea, but you don't need to since you already have a short contact section.

Ice skates have a rockered shape, and they carve pretty darn good on ice :-)

Part of the reason skates have good ice grip is that they are narrow and thus no lateral moment. However, if they were wide and the shafts were superstiff you would still have the same icegrip.

Part of the reason why a traditional ski needs to be relatively stiff is so that when you put them on edge so that the tips bend they also bend the ski in the central, stiffer, section, where the real pressure is.  If the skis are already bent you don't need the same stiffness.

This is all in theory off course, but I have put race bindings on some wider skis with 3/0.5 bevel and they grip pretty well. In Sweden we get LOTS of practice to ski ice.

Regarding Rockers, I have not been on any either except demoing a few times, but I did not make this up, it comes from an indie ski manufacturer I know, and he knows pretty much everything about ski construction.

I must be doing it wrong. I use to same movements on any ski and any condition w/ slight modifications.

Quote:
Originally Posted by slider

I must be doing it wrong. I use to same movements on any ski and any condition w/ slight modifications.

Try the way forward drill or dolphin turns on a heavily rockered skis and you may be in for a surprise.

Quote:
Originally Posted by Jamt

Quote:
Originally Posted by slider

I must be doing it wrong. I use to same movements on any ski and any condition w/ slight modifications.

Try the way forward drill or dolphin turns on a heavily rockered skis and you may be in for a surprise.

I'm off for a ski day and will try that. Should I wear a helmet?

Quote:
Originally Posted by slider

I'm off for a ski day and will try that. Should I wear a helmet?

Yes. Full face.
Quote:
Originally Posted by Jamt

Ice skates have a rockered shape, and they carve pretty darn good on ice :-)

Part of the reason skates have good ice grip is that they are narrow and thus no lateral moment. However, if they were wide and the shafts were superstiff you would still have the same icegrip.

Well, are you sure?

Some ice skates have rocker, but I thought that was for manevourability, not grip.  For example "speed skates" like they use in the Olympics to my knowledge are flat (I am not an expert on these, but it is what I understood), where as Goalie skates are rockered for manouverablility.  Yet they all get grip.

I understand your premise thou, I think, less contact patch, means more pressure, means more penetration into the ice, ergo better grip.

But in reality, more pressure, is more likely to exceed the sheer strenght of the snow/ice, thus losing all grip...hence conventional wisdom is longer, with less pressure is better......thoughts?

What I am particularily interested in thou, is that width doesnt affect grip.  Lemaster would certainly disagree...he argues, that the reason ice skates grip so well is their narrow width, and he uses that as the extreme example of how narrower skis grip better.  I admit to just taking this at face value....but now I am questioning it.  I understand it has to do with torque...but I drew the diagrams, and cant really make sense of it.  What I am finding is for the same degree of inclination and turn radius, the wider ski must be going alot slower.........ie...narrower allows you to go faster?  Intiuitiley that doesnt make sense to me really.  Same with risers...we know risers provide more torque....but.....how does this translate into speed/grip?

I'll come back to rocker and contact length on edge vs. flat and importance of torsional rigidity of skis later.

If we took a slalom ski and made it twice as wide, then tipped it up to 45* on ice, how would its contact with the surface be any different then a regular slalom ski tipped to 45* in the same hypothetical turn?
Quote:
Originally Posted by cgeib

If we took a slalom ski and made it twice as wide, then tipped it up to 45* on ice, how would its contact with the surface be any different then a regular slalom ski tipped to 45* in the same hypothetical turn?

Its contact would be the same.

But...the point is...as the ski narrows..right down to a skate...the amount of torque holding the ski on edge increases...as a ski gets wider it decreases...(same is true for ride height).

Now, I have always believed this increase in torque is what makes a narrower ski superior for edge grip...JamT suggests this is not true.  I am curious as to why he says that.

OK, I misunderstood what you were getting at.

Quote:
Originally Posted by Skidude72

But...the point is...as the ski narrows..right down to a skate...the amount of torque holding the ski on edge increases...as a ski gets wider it decreases...(same is true for ride height).

Now, I have always believed this increase in torque is what makes a narrower ski superior for edge grip...JamT suggests this is not true.  I am curious as to why he says that.

It would seem that as the ski gets wider not only does the torque "holding the ski on edge" decrease, it actually starts torquing the ski off of the edge …if we look at it in relation to the resultant force anyway. Would it make sense to say, when the resultant force is to the outside of the edge we are working against it and when it is inside of the edge we are working with it, to hold the ski on edge? I take Jamt's statement that you quoted above to mean that if there was sufficient torque to keep them on the edge, then the edge would hold. Is getting that torque efficient though? Would a racer be able to hold the ski on edge in their high G turns on a 130mm wide slalom ski?

I don't like my fat skis on hard surfaces and seem to have to lever the boot to get them to stay up on edge, since I'm actually lifting myself off the surface toward the inside of the turn in opposition to centrifugal force pulling to the outside of the turn. I don't like it on my knees and I don't feel it is efficient, but I doubt the ski cares as long as I find some way to keep it tipped.

I'm curious in Jamt's thoughts as well.

I think you guys are missing the whole enchilada with skates and narrow skis, it has to do with the alignment of your foot to the edge.of the ski/skate and geometry. There is a chapter on this in Ron Lemaster's book. I will see if I can  find it!

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