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# Tail follows tip = Carving

This is an offspring from the aft thread.

Consider the following picture, skiing from bottom up:

At A the skier retracts, and the skis flow with no or little contact until B when they are pressured again (acive or passive).

Between A and B the skis are guided with the tails following the tips. At point B the skis are pointing in the same direction as the CoM trajectory (the line between A and B). Thus the skis can be pressured again with no skid.

The guiding of the skis can be passive like in anticipation, or active via counter.

You could say that the skis are following a carved track, but they are not carving a ditch and not affecting the CoM trajectory.

You could also say that the skis are pivoted into the next turn

So, to the quesion. Are the skis carving between A and B, or are they pivoted between A and B?

I think that this is behind some of the misunderstandings in all pivot vs carving discussions.

If the edge tracks look like this you're carving:

You could also pivot between A & B, and then resume carving at B.

Jamt,

Since you're looking at the idea from a CM Trajectory perspective I thought I'd modify your original drawing with some info that I think is a teeny bit more accurate for the sake of discussion.

I've drawn a red curve over your original CM path. This curve depicts a more likely CM path based on the (required) minimal pressure necessary for skis to actually 'carve' out of the old turn and into the new turn (I'm assuming no 'Air Pivot' nor 'Air Carve' here).

Even when the skier isn't deliberately supporting their CM firmly against the skis there must be at least some pressure on the skis to keep the edges pressed against the surface. With an obligatory Equal and Opposite requirement we need that minimal pressuring-force to come from somewhere. I think it comes from "The CM" in a gross sense, but more accurately - from the Mass in components of the lower leg and ski gear.

As I see it the skier's CM might only be (say) 97% launched - with the remaining 3% resting lightly on the skis to keep them pressured just enough to carve the very large radius depicted at that phase of the Sine Wave ski track you've drawn. This tiny pinning-pressure can be created by launching our CM slightly more down-the-hill rather than "straight" at our desired re-engagement destination.

Via flexion/retraction the skier's CM can be "greatly released" (but not entirely) from the old turn but still be gently guided toward the point of actual edge-neutral. This 'gentle guidance' of the CM provides the light pressure necessary for keeping the ski-edges pinned during the float phase.

As the Skier reaches actual edge-neutral (flat to the sloped surface) no directionally-redirecting force is needed and the skier's CM very briefly travels 'straight' (ignoring ballistic path implications).

The moment the skis roll far enough onto the new edges to again warrant some pinning-pressure the CM begins it's new turn also - due to the reaction force of creating that slight carve. It happens so imperceptibly that we generally don't notice it. Still, if those edges are tipped, engaged and pushing against the snow (even lightly) then something must be Equally and Oppositely reacting somewhere.

In the interest of Full Disclosure ... In the text above I used "The CM" as my reference point for the necessary Mass to work from and that's not strictly true

In the case of a multi-segmented skier each body-part has its own Mass. The lower-leg, feet, boots, bindings and skis might have enough Mass themselves to accomplish the pressuring job on their own. A highly skilled skier with a deft sense of 'Touch' might well exclude 99.9% of their Mass above the knee from the equation, though I'm not sure how this could be proven. Considering the muscle tension present in such active turns I'm pretty sure most skiers (including those highly skilled) have much more than just lower-body components involved in pressuring the skis in the moments of interest.

Further, any effort the skier makes to extend their legs to enhance surface contact creates an even larger reaction driving the CM along an even tighter radius curve into the new turn.

.ma

I think the most important thing is what the skis do when they hook up. After a pivot at the transition the skis usually skid for a while before hooking up in a carve again. This can be the intent or something you did not want. If you are learning how to carve then its important to get that pivot out of your system. If you are a racer or an advanced all mountain skier you need to pivot some times. There is a very good drill where you jump up in the air off of your old edges and land on your new edges and carve cleanly at both ends. So its deffinetly a question of take off and landing. Remember, as your skis leave the ground your path is relesed from its turning component and you are continuing in a straight line. Its the skis that are turning you in a carve.

I'd say that the skis are carving. Also, in the original montage of the "aft" thread, I'm not so sure that there is all that much pivot (kinda depends on the accuracy of the montage).

Quote:
Originally Posted by epic

I'd say that the skis are carving. Also, in the original montage of the "aft" thread, I'm not so sure that there is all that much pivot (kinda depends on the accuracy of the montage).

Funny you say that becuase it was actually the reason I started this thread. The direction change of the skis from start of retraction until they are fully engaged is quite substantial. If you consider this carving yes then I agree that there is not so much pivot. However, if you consider guiding of the skis without pressure to be pivoting, there is a lot of pivoting.

IMO opinion the skis are not carving unless they are pressured into reverse camber.

A ski is carving when the edge of the ski is moving parallel to itself.

It's no wonder so few skiers can execute a decent carve. A subset of [some of the alledged best] ski instructors from around the world can't even agree on a definition for it!

Quote:

It's no wonder so few skiers can execute a decent carve. A subset of [some of the alledged best] ski instructors from around the world can't even agree on a definition for it!

If you are so much better perhaps you have a definition.

Another wonder is that your homecrew does not even recognize that Marcel is pivoting.

Quote:
Originally Posted by Jamt

If you are so much better perhaps you have a definition.

Another wonder is that your homecrew does not even recognize that Marcel is pivoting.

With a prevailing attitude like what you just displayed it should not come as a surprise to you that I would rather spend my efforts advancing my own skiing as opposed to the skiing of those who already have themselves convinced (and are desperately trying to convince others) that they already know what they are talking about.

Quote:

Quote:
Originally Posted by Jamt

If you are so much better perhaps you have a definition.

Another wonder is that your homecrew does not even recognize that Marcel is pivoting.

With a prevailing attitude like what you just displayed it should not come as a surprise to you that I would rather spend my efforts advancing my own skiing as opposed to the skiing of those who already have themselves convinced (and are desperately trying to convince others) that they already know what they are talking about.

I never give attitude unless it's a returned favor.

Quote:
Originally Posted by Jamt

Quote:

Quote:
Originally Posted by Jamt

If you are so much better perhaps you have a definition.

Another wonder is that your homecrew does not even recognize that Marcel is pivoting.

With a prevailing attitude like what you just displayed it should not come as a surprise to you that I would rather spend my efforts advancing my own skiing as opposed to the skiing of those who already have themselves convinced (and are desperately trying to convince others) that they already know what they are talking about.

I never give attitude unless it's a returned favor.

I got no sense of any "attitude" from Heluva's original post.  It sounded more like a general tongue in cheek comment...and I agree it seems like everyone has a different definition of what constitutes as a carved turn.

I got no sense of any "attitude" from Heluva's original post.  It sounded more like a general tongue in cheek comment...and I agree it seems like everyone has a different definition of what constitutes as a carved turn.

Maybe I interpreted too much out of Heluva's statement, if that is the case I apologize.

Aren't these tracks offset the wrong way?

Either way you go - downhill at top or bottom, I can't see how rolling onto the new edges will have the tracks like this.

If the top is downhill, we have a left turn to a right. So you'd be on the left edges, then roll to the right ones. So the top curves should be on the right of the bottom ones. That is downhill of the previous turn.

If bottom is downhill, It's still a left to right turn. and those bottom curves should be on the other side- downhill of the top tracks.

n'est-ce pas?

Originally Posted by mogulmuncher

If the edge tracks look like this you're carving:

You could also pivot between A & B, and then resume carving at B.

edit:

Well we have here Physicsman's thread from '06.

and then a Snowheads gargantuan thread on ski tracks in response at the same time:

No one can even agree on what they are suppose to look like. It's quite complicated to express mathematically.

Edited by Tog - 1/4/11 at 12:07pm

If tail follows tip really does mean carving, then a straight run down the fall line is carving.

Quote:
Originally Posted by mtcyclist

If tail follows tip really does mean carving, then a straight run down the fall line is carving.

Or making a 360 from a static position.

Quote:
Originally Posted by Ghost

A ski is carving when the edge of the ski is moving parallel to itself.

Nice..!

If Ghost adds a minor tweak like this:

"A ski is carving when all points along the contact edge of the ski are moving parallel to themselves"

...then his idea becomes nearly infallible. (accepting that "parallel to themselves" means parallel to the tangent of the curve at the point...)
Quote:
Originally Posted by mtcyclist
If tail follows tip really does mean carving, then a straight run down the fall line is carving

The refined definition now eliminates this possibility since both ski-edges have sidecut and are therefore curved such that some portions of each edge fail the test.

.ma

Quote:

Originally Posted by michaelA

Quote:
Originally Posted by Ghost

A ski is carving when the edge of the ski is moving parallel to itself.

Nice..!

If Ghost adds a minor tweak like this:

"A ski is carving when all points along the contact edge of the ski are moving parallel to themselves"

...then his idea becomes nearly infallible. (accepting that "parallel to themselves" means parallel to the tangent of the curve at the point...)

Quote:
Originally Posted by mtcyclist

If tail follows tip really does mean carving, then a straight run down the fall line is carving

The refined definition now eliminates this possibility since both ski-edges have sidecut and are therefore curved such that some portions of each edge fail the test.

.ma

Well how are you going to define contact edge? The whole edge or what's in the snow? At what viewing scale?

Look at these slow motion shots. Even when these racers are "carving" the skis are often flopping around. You really only see this in very high speed footage. Certainly not all points are moving parallel to themselves. I know, nit picking!

US Ski Team in NZ:

Video by tgskier

skis are carving when used to slice up turkey.  everything else is just a skidded turn. ;-)

Quote:
Originally Posted by majortato

skis are carving when used to slice up turkey.  everything else is just a skidded turn. ;-)

can you guide the knife while slicing turkey? or does it just follow the sidecut of the knife?

Quote:

It's no wonder so few skiers can execute a decent carve. A subset of [some of the alledged best] ski instructors from around the world can't even agree on a definition for it!

I can ARC and carve :)

Quote:
Originally Posted by BushwackerinPA

Quote:
Originally Posted by majortato

skis are carving when used to slice up turkey.  everything else is just a skidded turn. ;-)

can you guide the knife while slicing turkey? or does it just follow the sidecut of the knife?

The best turkey carvers will use the knife's sidecut and make clean slices.  If you pivot the knife too much, you'll end up getting ugly pieces of turkey everywhere.  Noone will want to eat it and Thanksgiving would be ruined.

I was taught to carve turkey by the best turkey carver in the world.  I then invented movements to improve on this turkey cutting style.  Other people think that they know how to carve turkey, but they just don't get it.  Anyone that I have shown how to carve turkey can tell that even the so-called-turkey-carving experts are doing it all wrong.  Even my beginning turkey carvers can tell an imposter the second that he/she makes a slice.  My turkey carvers don't need those so-called credentials -- all those people that go to CIA or FCI or Le Cordon Bleu are deluded into thinking that they can carve turkey.  They can't.  They pretend to follow parts of my turkey carving style and think that they invented turkey carving.  They didn't.  I invented turkey carving, and only someone that I teach how to carve turkey can be a real turkey carver.  The Japanese can carve turkey, if they wanted to carve turkey.  But they don't.  Except when it is the secret ingredient on the Iron Chef.

Hey Tog,
Despite portions of the ski coming up off the snow I think the definition still works!

If the skier's ski is flat to the snow then both edges are in contact, but most of the contact edge doesn't meet the other criteria. If parts of the ski bound up off the snow (loss of contact) then those parts are no longer in considered in the evaluation! Only the points along the edge remaining in contact are tested for the other criteria.
Quote:
At what viewing scale?
Well now, that one is always a problem at some point, isn't it? Any evaluation of a physical surface for 'straightness' or 'flatness' or 'parallelness' breaks down when we examine that surface at the atomic level, right? (Fortunately, PSIA can't afford Electron Microscopes for Examiners.)

.ma

bbinder,

When is your next turkey carving camp? I need all the help I can get.

since when did guide mean pivot?

Quote:
Originally Posted by majortato

Quote:
Originally Posted by BushwackerinPA

Quote:
Originally Posted by majortato

skis are carving when used to slice up turkey.  everything else is just a skidded turn. ;-)

can you guide the knife while slicing turkey? or does it just follow the sidecut of the knife?

The best turkey carvers will use the knife's sidecut and make clean slices.  If you pivot the knife too much, you'll end up getting ugly pieces of turkey everywhere.  Noone will want to eat it and Thanksgiving would be ruined

Quote:
Originally Posted by BillA

bbinder,

When is your next turkey carving camp? I need all the help I can get.

Thanks for asking.  At the current time, all of my turkey carving camps are booked for the next 1.5 years.  Sometime during the summer, I will post a list of new camps -- I am sure that they will book quickly.  In the meantime, I am in the process of opening up my new website (tentative address is .anyonecancarveaturkey.com), and my new book "Anyone Can Carve A Turkey".  You will need to pm me in order to to have access to the website forums, and I will not tolerate discussion of other turkey carving styles.  I will soon be revealing the one brand of knives that I consider capable of carving turkeys adequately -- the other knife maunfacturers just don't get it.  Other turkey carving forums spend pages and pages arguing over turkey carving.  They just don't get it.  I have distilled turkey carving to a basic technigue that works.  It works on any size turkey, cooked any style.  Those other so-called turkey carving gurus think that they can carve a turkey and think that they can teach other people how to carve a turkey.  They can't, because they don't get it.  And as a result, the rest of the people in the world who want to learn how to carve a turkey are getting poor instruction and learning the wrong way to do it.

Edited by bbinder - 1/5/11 at 7:20am

bbinder,

Quote:
Originally Posted by bbinder

I will soon be revealing the one brand of knives that I consider capable of carving turkeys adequately -- the other knife maunfacturers just don't get it.

Ah, that must be the knifes that are so sharp that you can carve the head of the turkey, the so-called HEAD turkey carving knives.

bbinder, hilarious.

still, on topic has anyone looked at my tracks issue above?

Dear Mr. bbinder,

I tried to go to anyonecancarveaturkey.com but it didn't work. I know I'm doing something wrong. Can you help?

I never learned the right way to carve. I started out with a cleaver and never graduated to the carving knife. I know it's my dad's fault, since he made me learn with the cleaver. Now I'm stuck. I've tried the new knives but when I chop with them they just break. I'm sorry, I don't have any video. (My young son chopped the camera with the cleaver. Thank God he missed my hand)

I found this video but now I'm even more confused. First off, he doesn't use the cleaver. Then, he's always eating the turkey. Worse, he rips it apart with his hands at times! (He's English, so maybe that's why? Do the English really know how to carve?)  Also, he's at times wiggling the blade and, (for pete's sake), chopping! What is this? I know you're supposed to slice.

What type of turkey carving school uses their hands? I thought this was carving.

I don't get it. Isn't there just one simple way to carve it??

All these centuries and you people still haven't figured out a way?

There's at least a dozen different videos all with different techniques!

No wonder I can't get a decent slice at Thanksgiving.

signed,

Frustrated, annoyed, and looking to carve. (Falc)

Video by JamieOliver