100% Carve

PaulBryanBill wrote:Hi,

I was watching some winter Olympic slalom skiers on tv. I noticed they carved their turns, but still skidded to a small extent. I wondered if a perfect skier could carve 100% of the time without skidding or scrubbing out any speed? I guess such a skier would pick up a lot of speed and therefore need to be very strong to deal with the large g-force encountered when carving fast and inclined into the turn. Any views?

I have found the answer to your question, but it's in a 50 page PhD thesis (Brodie 2009). What it says it that there is a trade off between taking the shortest route between the gates (which will involve skidding) and taking the longer route which will be faster because the turns can be carved, and that the best method will vary for different parts of the course etc.

It also says that slalom racers use the techniques of lateral projection (which might possibly be my 'step turn' I'm not sure) and pumping (p47).

It's extremely interesting but it's an in-depth read :lol:

http://www.sportnz.org.nz/Documents/Research/awarded-grants/Brodie%20(2009)%20Optimisation%20of%20Performance%20in%20Alpine%20Skiing.pdf



Ally

And there was me naively thinking I was the only one barmy enough to read scientific literature on skiing.

AllyG, unfortunately the link is broken.

http://www.sportnz.org.nz/Documents/Research/awarded-grants/Brodie%20%282009%29%20Optimisation%20of%20Performance%20in%20Alpine%20Skiing.pdf

The author, Matthew Brodie has a YouTube channel with some interesting videos.

Ski racers and recreational skiers have different goals!

Ski racers want to win above all! They will do anything and everything to get that less .001 second !

Recreational skiers want to have fun ! Want to enjoy the skiing experience !

Yes we can learn from racers,,but when I ski I do not have racing poles in mind, pre-determined race course in mind,,getting that .oo1 second off the course! I allow my skis to find best line, find that softest snow, look for that best view, look for that steepest zone,,,,, Pleasure is my goal !

In short I want freedom to soar !

Do I think of using the fastest line to get down the slope ? Never ( well sometimes,,to be honest ) !

I want that "experience" to last as long as possible ! I once skied with a young skier who just skied down straight ( the "how many runs can I do in a day " attitude ) ! While I was going up with him I mentioned, "you paid a lot for this ski lift ticket,,,,,why not make the most of it by skiing ALL the slope rather than just 2 meters of it ? "

The goal of skiing is pleasure. Carving is one of the ways to get this pleasure ! It is not a goal in itself !

In powder skiing carving is very secondary,,,,Floating,,is the ultimate pleasure in skiing!

Back to my slopes,,,,,,

Pavel

SwingBeep wrote:And there was me naively thinking I was the only one barmy enough to read scientific literature on skiing.

AllyG, unfortunately the link is broken.

SwingBeep - thanks for fixing the link for me and putting up the U- tube video. :thumbup:

And I am interested in reading up on these sort of things.

Ally

Anyway, talking of pure carved turns, skiasweetspot share this vid on FB. Just beautiful... The simultaneous edge changes are so sweet

Trencher, that is a superb video, great find, thanks for sharing. Every turn is different and yet has all the same components.

I ski like that in my head :D

Thanks for the video Trencher :D

I found it very helpful as because it's in slow motion you can see how the skier moves up and down and leans towards the centre of the turn. As far as I can see he's in his most upright position when the skis are flat, then he starts to put them on edge and leans into the turn, then he moves back towards a more central position as the edge decreases (but still with his legs bent), then he moves up nearly to the upright position as the skis run flat on the snow and then he does the same thing again only leaning the other way.

Any ideas? Have I got this wrong?

Presumably it's the edging of the skis and the leaning which is increasing the friction on the snow which is providing the centripetal force and stopping him from just going in a straight line and allowing the skis to make a circular motion as they're designed to do.

It's a long time since I studied any physics but this seems to explain it quite well:

http://www.physicsclassroom.com/class/circles/u6l2c.cfm

I know from trying this myself, that the more you lean the tighter the circle/turn you can make (within reason of course).

What is puzzling me is that the PhD thesis article on selecting the best line through a slalom course doesn't mention centripetal force, only ground reaction forces, snow resistance, wind drag, and gravity.

Anyone got any thoughts on this?

Ally

Thanks for everyone's input on this - it makes interesting reading.