What initiates a turn?

[Xinga]

Ski club season has started again, yay! But with limited terrain open, our instructor led club groups spend a lot of time on drills and thinking about the mechanics of skiing.

One of my instructors has given us a homework assignment to think about and ask other ski pros the question in the title: What initiates a turn?

I have also added a dimension to the question by wondering whether the turn initiation is different whether you're doing wedge turns or parallel turns?

Thoughts?

 

[bounceswoosh]

Is the answer the same whether you're smearing, slarving, carving?

 

[jellyflake]

1) If you relieve the pressure from your edges then your skis will follow gravity and turn into fall line.
2) If you press your edges into the snow then the ski will follow its edge's radius.
3) If you make any rotation with your body (e. g. rotate with your shoulders and hips into one direction) then this will have a physical impact on your skis (that you can either let happen or fight).

 

[Xinga]

Releasing pressure from edges: what if you're sliding straight down the fall line, in neutral (equal pressure on all 4 edges)? What initiates a turn from there?

 

[bounceswoosh]

Releasing pressure from edges: what if you're sliding straight down the fall line, in neutral (equal pressure on all 4 edges)? What initiates a turn from there?

Remembering I haven't been able to ski this season ...

1) The skis need to somehow tip onto edge so that the sidecut can be applied to the snow, which applies an arc. This can be accomplished using muscles in feet, lower leg, upper leg, or tipping the whole body. (I wonder if there's a way to describe sidecut engagement in ways that relate to drawing a circle with a compass.)

2) Again because smearing is a thing, a turn, or anyway a change in direction, can be initiated using rotation of the ski. Again could start from any part of the body.

(Not a snow pro - I think technically you were only asking pros.)

 

[bounceswoosh]

Unless of course the surface of the snow is uneven and redirects you without any intent on your part =)

 

[heather matthews]

If the skis are flat and in the fall line I guess you are thinking about making a dynamic parallel turn and as such your weight (centre of mass) is already starting to move across your skis in the direction of the turn.This movement actually begins prior to and is blended with the completion of the previous turn. Its all a combination of lateral vertical and rotational movements blended to ensure control through the three phases of the turn.

 

[volklgirl]

It depends on if we're talking about static or active turn initiation.

Static turn initiation happens naturally on any slope if the feet are flattened in relation to the slope.....the skis will automatically seek the fall line with no help from us at all.

Active turn initiation also requires flattening of the feet/skis against the slope, with the addition of edge pressuring (carving using the side cut of the ski to arc it's natural turn shape) and weight shifting, and/or some form of rotational force (skidding, sliding, or slarving). The combination of all those forces is what allows us to make turns smaller or larger than the stated turn radius of the ski.

Releasing pressure from edges: what if you're sliding straight down the fall line, in neutral (equal pressure on all 4 edges)? What initiates a turn from there?

Pressuring the tips of the skis and tipping of the feet, engaging the front edge of the ski and the turn radius built into the ski. Or, pressuring the tips of the skis and applying some type of rotational force (rotating the foot in the boot, driving the knees or hips into the turn, moving the center of mass toward the center of the turn, or even turning the shoulders and/or whole body).

 

[Skisailor]

Interesting question. First we have to define where turns "start" and "end".

In the fall line? Across the fall line?
At edge change? (i.e. When skis are flat)

For we mere mortal recreational skiers - Which way are our skis generally pointing when the edge change happens?

 

[volklgirl]

The "initiation" from straight down the fall line is actually the belly to end of the turn.

Turn initiation SHOULD start with the skis almost directly across the fall line. If you don't flatten the skis against the snow while directly across the fall line, there is no way to start the next turn and the skis will simply continue their arc up the hill until gravity and friction causes them to come to a stop.

True experts actually start inside foot flattening and tipping with center of mass movement toward the next turn even before the skis cross the fall line, so the simultaneous edge change can happen right at the fall line (at least that's what I've been striving for for years from my race training).

Intermediates tend to traverse across the hill then "fudge" into the next turn because they're stuck across the fall line with no momentum down the hill to initiate the next turn.

 

[Skisailor]

Turn initiation SHOULD start with the skis almost directly across the fall line. If you don't flatten the skis against the snow while directly across the fall line, there is no way to start the next turn and the skis will simply continue their arc up the hill until gravity and friction causes them to come to a stop.

True experts actually start inside foot flattening and tipping with center of mass movement toward the next turn even before the skis cross the fall line, so the simultaneous edge change can happen right at the fall line (at least that's what I've been striving for for years from my race training).

Intermediates tend to traverse across the hill then "fudge" into the next turn because they're stuck across the fall line with no momentum down the hill to initiate the next turn.

Yes. That sounds like a good race trained approach. I would say that yes - Lindsey Vonn changes edges (in a microsecond) while her skis are perpendicular to the fall line. But most recreational skiers don't, and never will, be able to make the edge change there.

Has anyone ever paid attention to where their skis are pointing at the moment they go flat before you change edges?

I never did!! Until last year. Lol.

 

[volklgirl]

Has anyone ever paid attention to where their skis are pointing at the moment they go flat before you change edges?

I never did!! Until last year. Lol.

And??????

 

[Skisailor]

It depends!!

When I'm doing pivot slips it happens right in the fall line.

When I'm doing higher speed GS turns it happens at about 70 degrees off the fall line.

I think for the average intermediate to advanced skier, edge change happens at about 45 degrees off the fall line.

 

[Xinga]

Why is neutral less likely to be across the fall line for skiers than snowboarders? It's pretty common for me to see nice snowboard carve tracks with neutral right across the fall line -- I look for these and similar ski tracks when riding the lift, and don't see the ski ones as often.

 

[Skisailor]

Why is neutral less likely to be across the fall line for skiers than snowboarders? It's pretty common for me to see nice snowboard carve tracks with neutral right across the fall line -- I look for these and similar ski tracks when riding the lift, and don't see the ski ones as often.

Well - it's not really "neutral". What we are talking about is making the edge CHANGE while the skis are still across the fall line. That means in an instant you go from being on the uphill edges (quite comfortable and normal) to being on the DOWNHILL edges. You have to be going at a pretty high rate of speed to do that so the G forces will hold you up. Otherwise you will hit the ground in a hurry!! That's why it's primarily a move that ski racers use. Most of us can't make the edge change that high in the turn.

No difference with snowboarding. Any beginner snowboarder knows the feeling of getting on the downhill hill edge too early in the turn. It slams you to the ground!

 

[nopoleskier]

my simple answer is shift in weight and/or pressure dictate turns.. (exactly where that weight shift and pressure change occurs is the excellent discussion going on here)

 

[volklgirl]

Why is neutral less likely to be across the fall line for skiers than snowboarders? It's pretty common for me to see nice snowboard carve tracks with neutral right across the fall line -- I look for these and similar ski tracks when riding the lift, and don't see the ski ones as often.

I would guess much of it has to do with skiers bracing on the downhill ski as they are starting to make the change over with the uphill ski (backwards from what the experts aspire to), while snowboards don't have 4 edges or 2 feet to rely on. Their edge change is instantaneous, no matter where it occurs in the turn, of necessity. Trying to wait to make the edge change on a snowboard simply gets you stuck on the uphill edge, requiring rotational forces to get you out of that "stuckness".

 

[AdkLynn]

I would guess much of it has to do with skiers bracing on the downhill ski as they are starting to make the change over with the uphill ski (backwards from what the experts aspire to), while snowboards don't have 4 edges or 2 feet to rely on. Their edge change is instantaneous, no matter where it occurs in the turn, of necessity. Trying to wait to make the edge change on a snowboard simply gets you stuck on the uphill edge, requiring rotational forces to get you out of that "stuckness".

Initiating a turn on a snowboard requires a fleeting moment of release of edge, un weighting, floating down the fall line for a second, and rolling onto new edge. Very much like skiing, just with only two edges! Unless you are on a carving board, which is like ski racing, high speed instant edge change across the fall line! With hard boots! You are right about hesitating to make the edge change, most beginning snowboarders are afraid of the fall line at first, which results in some hilarious uphill falls, believe me, I know!

 

[tesdavis]

"Water your pole plants"! I was taught in the 1970s. Plant your pole downhill, shift weight to the downhill ski and arc around it. But keep the eyes looking downhill. Again, old instruction but it works for me.

 

[Gloria]

Well - it's not really "neutral". What we are talking about is making the edge CHANGE while the skis are still across the fall line. That means in an instant you go from being on the uphill edges (quite comfortable and normal) to being on the DOWNHILL edges. You have to be going at a pretty high rate of speed to do that so the G forces will hold you up. Otherwise you will hit the ground in a hurry!! That's why it's primarily a move that ski racers use. Most of us can't make the edge change that high in the turn.

No difference with snowboarding. Any beginner snowboarder knows the feeling of getting on the downhill hill edge too early in the turn. It slams you to the ground!

A ha! An instructor friend was trying to get me to do this in bumps today. Which were horrible by snow conditions. I was able to get it at the apex or belly everywhere else but was only able to succeed by luck every few turns in the bumps. Speed makes sense, they were brutal I was going much slower. Not that I am going to go out and try going faster in those conditions, but maybe when more forgiving.