Originally Posted by loki1
Removing the bos of support may allow the com to move across the skis but it does not automatically (magically) cause an edge change. Which is the only absolute that needs to happen during transition.
The thing that is most important changing edges which requires the com moving over the bos but that is not the cause of the edge change. Simply flexing or extending does not cause an edge change either.
yup - these are related and both necessary - edge change can't happen without crossing and crossing can't happen without edge change (or results in a thud).
There is a way though where the first bit about the COM causing the edge change, say in speed skiing, there's so much time and such big forces that you can simply wait for a passive extension of the leg because of the COM crossing - often resulting in that bit of A-frame we see in COM releases... but that's not in the scope of this discussion, for sure.
Otherwise, yes, flex/extend is the required thing (I never really agreed with the old coaching adage with inclination of COM causing edging, still present in many manuals). We disagree some, I think, on the I guess ratio of ankle to femur work involved in tipping the skis on edge at different places in the turn, but yeah.
Originally Posted by Jamt
Originally Posted by loki1
This is simply not true.
ILE will move the com further inside the turn and away from the bos. It will also transfer pressure from the outside ski to the inside ski.
OLF will move the com towards the bos and towards the outside of the turn. This may eventually cause the com to cross the bos but only after the range of flex has been exhausted. It still will not cause and edge change.
Remember in a turn the outside leg is extended more than the inside. Also the only time ILE and OLF make the com move laterally to effect edge angle is when in a wedge.
No simple truths. If you transfer weight from an extended outside to the inside the CoM comes closer to the BoS, because the BoS moves from the extended outside to the flexed inside.
You also change the balance state so that you will "vault" towards the next turn.
You don't even have to do any flexing or extending or edge moves, just like PSI man.
"no simple truths" - No kidding... I don't particularly fancy much the ILE. There is a fine line between transferring early to the inside leg, which will be the new outside leg and then extending it. The question is really one of when the extension happens: before or after skis flat. If it's before, which I think an ILE is, then it does push the body back up the hill and slows things down...
If you just transfer some weight to it and the extension is after skis flat, then it's what Ted does and it's fine. The point of that is that when transferring to the uphill edge of the inside ski, the balance is changed drastically like Jamt noted, as that's well under the COM and that is one of the benefits of doing that.
The bold part is interesting - haven't actually thought of it that way, but of course.
I think we're missing this picture from our own animation master when talking about releases of COM and skis and force vectors and why things cross:
Some (TE?) seem to equate the arc and path of the skis with that of the COM - that's barely true in low level skiing... and far from reality in high end skiing...
If one simply removes the support of the COM, the paths will cross just because they were never the same...
Edited by razie - 1/11/16 at 8:26am