Re: tfr - restarting

[carver_hk]

Hi Bolter & Max - I can see it now. Thanks for the great hint.

Max - By well behind I meant my hip was behind my heel. Second though, actually I don't quite understand why it does matter as I could bend my upper body forward to have my balance point centered.

[BigE]

Is it easier to tip your feet with your hips centered or with your hips back?

[carver_hk]

Is it easier to tip your feet with your hips centered or with your hips back?

I just made a quick test to tip my feet on the floor with variable flexion of my knees and a corresponding bending forward of my waist so that my weight is centered. In the case of less knee flexion it seems it is just plain easy to tip both feet. In the case of deep flexion, meaning butt well behind my heel, it seems tipping alone will have more weight on the ball of the left foot and more weight on the heel of the right foot, for example. Or the other way round if you tip the other way. To keep the force equal along each feet in the deep knee flex case I have to resort to more movements. Is this finding correct?

[BigE]

Yes, it is easier to tip with hips over feet -- biomechanically, the kinetic chain works better.

[carver_hk]

Yes, it is easier to tip with hips over feet -- biomechanically, the kinetic chain works better.

May I further deduce that it explains why there is a certain amount of CA required at the moment of release and the engage depending on the amount of knee flexion at the moment because it is better to have a equal amount of pressure from ball to heel on both feet?

[BigE]

Not my understanding....

It's better to have a certain amount of CA when tipping to COUNTERACT the tendency of the skis to twist into the direction of the turn. Counteraction counteracts the rotary force that can break the tail of the ski free.

[carver_hk]

Not my understanding....
It's better to have a certain amount of CA when tipping to COUNTERACT the tendency of the skis to twist into the direction of the turn. Counteraction counteracts the rotary force that can break the tail of the ski free.

Thanks for clarifying.

[carver_hk]

This update I make sure that I have even pressure along the skis edge by adjusting CA before starting off. Thanks in advance for any help.

http://www.youtube.com/watch?v=codacRtEerE

[Max_501]

Look at the book to see how much CA HH shows at the start and try to copy that.

[geoffda]

Look at the book to see how much CA HH shows at the start and try to copy that.

I think we have to be a little careful when we talk about CA in the context of a static TFR. If you start with CA, it represents the CA that you would have from the previous (and in this case non-existent) turn. That is well and good, *but* keep in mind that if you are still facing down hill once your skis are flat, you no longer have CA, you have rotation. Because of the static start, the lack of forces, and the fact that the skis stay flat for a (relatively) long time, it is really hard to actually square up and then get proper, early CA as you would in a dynamic turn. As a result, you get some help from combination of your torso "unwinding" due to the rotation as well as the torque from the blocking pole plant. This is all subtle and passive and I don't see a problem with it in this limited context, but it is hard not to do. The more CA you start with, the more likely you are to rotate. If you watch Harald's TFR from his blog post: http://www.harbskisystems.com/hblog/200 ... lease.html , you'll see even he is slightly rotated when his skis are flat (skis flat at like 7 o'clock, zipper still pointing across and down the hill). So my point is that I don't think starting with a large amount of CA necessarily makes sense as a goal. I would suggest that any CA at the start is largely a side-effect of needing to locate the pole back and out of the way rather than a deliberate movement. Thoughts?

Meanwhile, HK, I like your TFR. The release is good. You let go of the hill and you move with your skis as they release. You CA along with your Phantom Move finish as you should. My only criticism would be that you finish square. In a real turn, you don't let go of your CA until you release. Since there is no release to a new turn here, you should finish with CA.

[Max_501]

Take a look in the book (page 48 of Expert Skier 2) and try to match that amount of CA (the frame by frame images in the book make it easy to see).

That is well and good, *but* keep in mind that if you are still facing down hill once your skis are flat, you no longer have CA, you have rotation.

Perhaps some passive rotational forces at play but not active. Active rotation requires a movement of something in the direction of the turn. So, if you are going to use your torso to steer into the turn then the torso will be moving into the turn. For the TFR and BPST the torso is held fairly stable via CA movements which are muscle movements that move the torso to the outside of the turn.

[geoffda]

Take a look in the book (page 48 of Expert Skier 2) and try to match that amount of CA (the frame by frame images in the book make it easy to see).

That is well and good, *but* keep in mind that if you are still facing down hill once your skis are flat, you no longer have CA, you have rotation.

Perhaps some passive rotational forces at play but not active. Active rotation requires a movement of something in the direction of the turn. So, if you are going to use your torso to steer into the turn then the torso will be moving into the turn. For the TFR and BPST the torso is held fairly stable via CA movements which are muscle movements that move the torso to the outside of the turn.

Yes, I see that Harald starts with CA, but why? Is starting with CA an intrinsic part of this drill or is it simply a side effect of pole placement? The answer to this question determines whether HK *should* be starting with more CA. From where I sit, I can't see a reason why starting with CA is important. While it does make the drill easier due to the passive rotary it introduces, in a "real" turn you would want square hips at transition. So while I agree that the rotary forces involved when starting with CA are passive and aren't going to cause bad movements, it is still rotary and not representative of what we are looking for in a "real" turn. So wouldn't the ideal be to start with square hips as JClayton suggests? Personally, I don't think this can be achieved if you are using poles, but if it is the theoretical ideal, then that would suggest that the amount of CA at the start is not important at all (unless the person trying the TFR is having trouble getting their skis to come around after release). Hopefully that makes more sense. I'm definitely interested in understanding the "why" behind the suggestion.

[Max_501]

At the end of a real BPST there would be the same amount of CA that HH demonstrates at the beginning of the TFR drill. Since the idea is to build a BPST by linking the TFR its probably a good idea to start in the right place with the TFR.

[carver_hk]

There is a lot to learn from you guys discussion. In working out the tfr my own feeling is that the right(not too much, not to little) CA give me better gripping and therefore make the release a lot easier. Is this feeling valid?

I have another vid from the same session. This one have more CA. But there are very mild rotation just before falline. More input by comparing the two?

http://www.youtube.com/watch?v=Aa1AiRawVG4

edit: this is an earlier version taken before I found out I have to relax my right arm & shoulder.

[Max_501]

As soon as the skis hit the fall line begin to CA. Make sure to include the pelvis as part of the CA movement.