Originally Posted by checkracer
The resultant force (centrifugal/gravity):
shouldn´t it aim at within the skier´s support area, i.e. between the both edges engaged, practically not far from the BTE?
IMO, if the discussion almost started (or alt least accelerated) around a diagram, it should be correct
Yes, Checkracer, I'll second Powderhoundin and say you make a good observation here. The resultant force vector should only point at the inside edge of the outside ski if that ski is harboring all the turn forces. Any pressure observed on the inside ski indicates that not to be the case. Determining just how much pressure is on that inside ski from a photo, and then assigning a corresponding ground intersection point for the resultant force vector is the hard part.
I know everyone, this is getting complicated, and it seems to be taking us off topic, but it's really not. In fact, what it does is lead us into a new line of discussion that explores how we can use Powderhoundin's excellent diagrams to gain better understandings of how we control balance points.
Understanding the following is key to grasping these new concepts, and being able to employ them in your skiing. For any particular turn of a known speed and radius the angle of the resultant force vector is constant, we have no control over it. Only by changing the value of M (centrifugal force) through alteration of speed of travel or radius of turn can we alter the angle of R (resultant force vector).
What's the significance of that? Simple. Because the angle by which R emerges out of the CM and travels to the ground can't be altered, it becomes clear that the only way we can change the balance point (the R ground contact point) is to change the location of the point in which in which R emerges (the CM). With a clear image of an R vector of constant angle in mind we can easily see that moving our CM further inside simultaneously moves the ground intersection point of R further inside as well.
This is how we balance guys. This is how we alter pressure distribution across the feet. The more we move our CM inside the more pressure our inside ski will be assigned. As long as we keep the R ground intersection point at or between our feet we remain in some state of balance. When it moves outside the feet we become out of balance, either falling on our side in R is inside the inside foot, or launching for the woods if R is outside the outside foot.
For some this concept of balance is understood intuitively without needing to grasp the physics behind it. For many others, coming to comprehend this provides a valuable tool for progression. It also might explain to some why I suggested in Pierre's "sixth sense" thread that people might want to play with the idea of focusing on an active hip. Where goes the CM, so goes R.
Nice job with this thread all.