Fortunately for Mike and Alex the weather had finally turned in their favour with sun and good cold snow. Clear skies at night cause the snow to cool much lower than the ambient air temperature due to radiation loss - as much as 14°C lower than the air! This temperature drop freezes and stabilises the snow pack to some extent. There was enough soft fresh off piste for us to be able to venture into it later in the morning - staying on gentle gradients and safe slopes.
Pivoting on the Face de Bellevarde
Today we warmed up with pivoted turns on the Face de Bellevarde - mainly because the black run was in good condition and also because the extra steepness actually helps when developing the pivot - at least at certain stages of development. Mike had the basic idea of the pivot - at least he understood that it was important to avoid getting onto the inside ski edge too soon in the turn. The steepness of the slope made it easier to visualise the placement of the skis downhill from the centre of mass. The pivot can only be executed if the feet are kept downhill of the body. Mike was unaware however of his strong tendency to stem the uphill ski further uphill (uphill of the centre of mass) and place it on its inside edge.
Visual Feedback
Rather than repeat my feedback to Mike I asked him to look at his own feet during the turn. Common advice is for skiers to avoid looking at their feet - but there is nothing wrong with doing this specifically for a purpose. The advice generally given is to stop some people from staring at the ground and then becoming paralysed by the consequent miss-perception of speed. By watching his feet Mike could see clearly what was going on and this immediately stopped the stemming and permitted efficient pivots to be carried out on the top ski. Some of the pivots were better than others, the problems being due to slightly failing to keep the centre of mass moving to the inside of the turn - but we would work properly on that aspect later.
Abdomen and Upper Body Rotation
Planting my pole between Mike's skis I asked him to raise his uphill ski slightly off the snow and to pull the inside of the tip against the pole. Facing straight ahead Mike would only feel a slight muscular activity from his adductor muscles - inside of the leg up to the groin. Turning the upper body to face downhill he would feel a much stronger force coming from the combination of the abdomen and the adductor muscles. This is the force required to swing the ski into a pivot. Mike's tendency was the opposite - to face across the hill and to corkscrew the upper body directly into the turn. This had to be changed so as to have the body already facing downhill and then be able to unwind the tension from the feet upwards through the body. Ideally the only rotation experienced for this is in the legs - at the hip joints.
Patience or Panic
Mike had a tendency to panic and then force the turn initiations. This is a normal response to anxiety about getting through the "acceleration" phase of the turn as rapidly as possible. Unfortunately this anxiety results in inappropriate rotational and twisting actions to try to force everything around as fast as possible. To correct for this you need to be aware first of all that it is happening and then have an alternative plan. The correct turn initiation is made by patiently accepting the initial acceleration, ensuring that movements are clean with the centre of mass and that only appropriate "inward" forces are applied through the legs. This can also be improved by understanding how the pivot provides a braking is action. The outside ski slipping into the turn with a sideways skid and so slows acceleration during the start of the turn - maximum acceleration only taking place directly in the fall line during the very brief and rapid change of edge. The next demonstration was designed to make this issue clearer.
Skis as Brakes or Accelerators
Moving onto a shallow slope I demonstrated some fundamental theory that lies behind the pivot. Over the years I only gradually became aware of how the pivot functions and part of that process took place when developing better forms of snowploughs for beginners. (Note that today I very seldom use snowplough with beginners for several reasons). For a snowplough to be useful it has to act as a brake - because that is the whole point of using a snowplough. The standard advice is to stem out the uphill leg and place the "outside" ski on its inside edge, then to transfer weight to it - usually by moving the centre of mass over it (corresponding with statics). This effectively turns the outside ski into an accelerator and puts the skier into an immediate and eventually life long panic. In addition the act of stemming out the uphill leg is training a disastrous and inappropriate muscle coordination pattern. The correct use of a snowplough involves first of all setting up the plough shape in advance - skis converging at the tips with the tails out as far as necessary to place the skis on their inside edges. The important aspect relevant to us here is that during a turn the centre of mass actually moves slightly towards the inside of the turn - placing weight over the inside or downhill ski at the start of the turn. This same ski is also flattened slightly as a result of this movement an so it can side slip towards the turn centre relatively easily. This ski can then be used to support and feed the skier into the turn while at the same time acting fully and effectively as a brake. Crossing the fall line the geometry of the mountain slope will cause weight to transfer to the new "lower" ski and for the turn to be completed with this ski taking over - also however acting as a brake because both skis were only used on their uphill edges and with a drifting/side-slipping action characteristic of any plough manoeuvre. The point to understand and perceive here is that the "pivot" serves to exploit the skis as brakes - not accelerators. Accelerators are useful for racing - but not for all skiing. With this explanation Mike gained a new perspective on pivoting and felt that the penny had dropped regarding understanding the whole process.
Lower Ski Pivot
Following on from the snowplough exercise we went onto the "lower ski pivot". Mike was still getting tangled up with his inside ski most of the time during the turns so this exercise was intended to correct that. The lower ski pivot is effectively a turn executed on the inside ski only. Taking the lead from the snowplough all the weight this time is transferred to the lower/inside ski at the start of the turn and the ski is kept on its inside (uphill) edge. A strong downhill pole support is required to get the centre of mass confidently over far enough to get the ski to slip into a sharp turn. Unlike the snowplough though an edge change is required in the fall line and for this the pole use is critical for encouraging the centre of mass to continue to move inwards towards the turn centre and to compensate for changing slope geometry. This exercise was addressing critical issues of both edge control and centre of mass control. One of the problems evident with Mike's lower ski pivot is that when it went wrong there was a clear upper body rotation and attempt to "force" the turn. This would happen to the extent that the uphill ski would actually cross over the lower ski in the air. Essentially this is the same as an uphill ski stem - but with the ski not even on the ground!
One Ski Skiing
Mike got on top of the lower ski pivot very quickly and so the next stage was to stay on the same ski and turn the other way - linking turns on one ski only. This makes clear the relationship between edge control and centre of mass.
Simultaneous Swing
Returning back to "normal" skiing on the outside ski I explained that although the turn was not now being executed on the lower ski it was necessary to swing it into the turn simultaneously with the outside ski - as if it were being used with weight on it even though it was weightless. Mike got it straight away and did his first clean pivoted turns unobstructed by the inside ski.
Two feet or one?
I explained that because the pivot can be carried out on either ski it can also be carried out on both skis. Off piste in deep snow it can be very useful to keep both skis close together to act as one pivoting platform - but the body must still coordinate itself as if it was supported on one leg only. When people stand directly on two feet in skiing it causes a breakdown of overall coordination.
Off Piste Stance
Progress was rather rapid and without much time available to consolidate - however the next step was to apply some of this in anger - which meant going off piste.
I explained to Mike (after the first face-plant) that it was best to adopt a slightly different stance when in deep or difficult snow. Imagine sitting on a chair in a room. Sitting down the centre of mass goes backwards. Now place the chair on a steep slope facing downhill. Sitting on the chair is now impossible because the centre of mass can't go behind the feet! Adopting the same posture while facing downhill permits the skier to keep his feet below him on the mountain - without any "backwards leaning" enabling easy access to the pivoting qualities of the skis.
Keeping the feet close together gives access to the support of the "two footed" pivoting platform - but for this to work well the turns should be quite shallow and kept close to the fall line. Keeping the feet close together and finishing turns across the hill causes the pelvis or entire body to rotate. It's not essential to keep the feet together but where the gradient is gentle this helps to keep the skis on the uphill edges all the time - and of course this is where it is not necessary to close the turns off much anyway.
If the feet come apart as will happen in more aggressive steeper fall line skiing where the turns are closed off properly - then the windscreen wiper effect of independent leg rotation is required to maintain the full mechanics of the pivoting action. The steepness of the hill however permits the feet to come apart with no risk of easily catching the inside edge and losing the pivot action.
Loading up the Ski
Mike had a couple of falls off piste - mostly due to lack of familiarity with the environment but at least one fall was clearly from the outside ski being edged and the body not being far enough inside the turn to deal with the consequences. When the skis are edged in deep snow the "lifting up" power of the skis is much stronger than on the piste. That's because the entire base of the ski loads up with pressure and under foot the ski bends almost like a trampoline. The hip flexibility we had been working on improving from the start contributes to being able to sink down and into the turn so as to prevent the ski from pitching the skier up and out of the turn too soon. This can also be achieved simply by following the skis and toppling over laterally - but not with the same control as with the pivot and with hip angulation/anticipation (facing downhill) involved. Despite down-sinking into the turn also loading up the ski even more the trade off is improved stability and control over when the ski rebounds the skier back up out of the turn. Coming back up out of the turn the skier can achieve an "unweighting" effect making the skis light on the snow and thus facilitating the start of the pivot into the next turn along with a downwards motion of the centre of mass as it starts to descend into the centre of this new turn.
In carving this same "loading up" move dramatically increases the G forces in the turn and dramatically tightens the turn radius. When carving the skier is moving the centre of mass over the top of the skis to change edge at the start of the new turn so there is no "unweighting" involved. In addition the legs can be used independently to insure that maximum pressure is gained from the dynamics and fully exploited at the turn initiation.
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