Использование центробежной силы при входе в поворот

How to use centrifugal force in initial stage of ski turn

Some believe that there is no centrifugal force in Nature. I will not argue with this, but I will denote that by centrifugal force I mean what is pressed against the outer wall in the carousel. That is, to feel the centrifugal force you need to be yourself in a turn but not watch it from the side. In turns on skis there is a mix of two extreme cases. One extreme – a sidelong descent across the slope, then a sharp redirection of movement (for example, jumping with a turn) and again an oblique descent. Looks like zigzags along a broken line. In this case, there is no movement along the circumference and, accordingly, there is no centrifugal force. The opposite extreme case is round turns, there is a centrifugal force. In a real ride, no matter how you want to always cut round turns, there is also a braking and straight sections. Therefore, the centrifugal force can suddenly disappear and appear. In the note, I will give observations on how to use centrifugal force to quickly load an external ski when entering the turn.

Centrifugal force (CF) depends on the turning radius (the steeper  is turning, the higher the CF) and the speed in the turn (the higher the speed, the higher the CF).

 

translation of words in the picture: traverse | first third of turn | second third of turn | last third of turn | traverse

I’ll bring a picture from the note:  Slalom, working on the technique in the 2017 season. Avoid inside ski forward. Red circles indicate the poles of slalom course. The following considerations will be about the turning area between the red arrows.

In the phase of sidelong descent before the turn there is no movement in a circle, and there is no centrifugal force. The center of mass of the skier is located higher up the slope. This is an equilibrium state with support on the lower ski. At the beginning of the first third of the turn, the center of mass passes through the skis and is lower on the slope (this moment is indicated by the left arrow). Begins a fall, which can be delayed slightly by angulation in the knees, as described in the article “Avoid inside ski forward“. It’s time to somehow “switch on” the centrifugal force, that is, to force the skies to go around in a circle. “Switch on” the centrifugal force will give support on skis, which will help until the end of the turn area indicated by the right arrow.




Let’s go away from slalom course. Let’s say that a skier starts turning on a shallow slope, and can afford to turn “from skis”, that is, how skis are turned, so it’s okay. In order for the ski itself begin to turn, you just need to put it on edges and lightly press down to the slope.

After edging, the ski does not immediately follow the arc, there is some lag. At high speeds this delay is imperceptible, but it still exists. At this time, the state is unstable, since the ski has already been edged, but centrifugal force does not press it into the slope yet. Therefore, there is a stepped feedback: just a little edge, so that could balance to keep stance, waited for the arrival of the CF, after CF arived the edging a little more, and so on.

This leads to more extended turns (a typical picture is turning on slalom skis by arcs as for a giant slalom) and to possible dragging by drift, since while feedback is in the way, the speed can get out of control. And the “angles” are less than desirable for such speed and turn parameters.

Now we will transfer such step-by-step edging back to slalom course. From the “steps” is retain only the first step: just edge the skis, waiting for the arrival of centrifugal force, have no time to wait arrival, let the skis slip. Skis slip in a straight line, so the centrifugal force does not come. The body remains above the skis, and the skis are flat, without the edging (all this is in the picture on the section between the arrows, then, when other forces press the ski, everything become beautiful). There is an alternative, for this you need to be gifted in acrobatics. Then after edge changing you can calmly fall down the slope, believing that you will not touch the ground, skis will come under the body and save 🙂





In general, at the entrance to the turn, there is a time when you can edge and bend the ski ONLY with the help of centrifugal force.

How to use centrifugal force at the beginning of the turn?

The CF has a “power button”. It is necessary to push the outer ski forward. To compensate stance, you can slide the inner ski back, but this is not necessary.

There is nothing strange about this, the external ski in the turn must overtake the inside. If this is not paid attention, then the skis are also turned, but not so fast. But the main thing is not even that. This movement actively drives the skis into a turn, as the outer ski overtakes the center of the masses and therefore immediately goes around in a circle. And as soon as the turn began, centrifugal force came, pressed the skis and provided the edging. That is, instead of “calling CF” in small portions as in the example above, everything happens at a time.

It feels at first really like pressing a button: the external ski is immediately loaded as soon as it began to move forward.

If to consider the approach to this point, then approximately so. At the end of the previous turn, the skies go forward from the body, so to start the turn you need to either overtake the skis with a body, make a dive, or pull your legs under yourself (for details see Slalom, work on the technique in the 2017 season. Shorten the arc). This will give re-centering. Then you need to make a edges changing, for example, to let the skis come up the slope “above the body” (more in the same note) or by knees. But after that, it is just necessary to start pushing the outer leg forward to engage the centrifugal force. In principle, these three movements can be combined into one and rolled into a habit 🙂





Vadim Nikitin DigInfo.ruVadim Nikitin

 

 

 

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