How to XCD on NNN/SNS?

[CIMA]

Snippet 08: Turns (3 of )

When you descend the slope, check the following two points:

• Being aware of pressure in soles and external forces
• Anticipating the changes of external conditions

Sensing pressure in your soles is crucial.
You need to mind not only the difference of pressures you feel between right and left soles but also its distribution inside each sole. Since your movement is very flexible thanks to soft XCD boots, the information coming from your soles relates directly to your body position you're taking. Be sensitive to the changes of the pressure in your soles always.

Though I'm not going to describe the matters of physics in detail, it would be beneficial for you to know the following external forces acting on you.

• driving force, or a force component of gravitational force
• reactive force you get from snow surface
• drag you get in your feet depending on snow conditions
• centrifugal force

First the driving force increases as does the angle of the slope. It is the force that lets you "fall." Don't be afraid of the force but cash in it. Advanced skiers know well that turning gets easier on steep slope than on shallow one. You don't have to turn proactively on the steep slopes: invisible driving force lets you turn.

Second sensing the changes of the reactive force from snow surface is important to tell the timing of turns. When the reactive force, such as buoyance in powder and repulsion from consolidated snow, is about to reach the maximum, that is the sign for you to initiate next turn.

Third the drag depends on snow conditions. If you ski on groomed surface, you feel little drag from snow. On the other hand if you ski on powder, you feel drags in your feet that would let you tumble forward in the worst case. The changes of drags caused by snow conditions can be sensed by your front ski as you make telemark turns. The drags may change according to the changes of hardness, lightness and stickiness of snow. The lighter snow gets, the more actively you can move.

Fourth the centrifugal force may not be a big issue because the speed of XCD is usually low.
Try not to angulate actively like you do on alpine skis or you'll fall down inside curving arc.

Don't fight against these external forces.
For example, don't make abrupt turns while the earth is wanting you to move along with fall-line. Transition from one motion to another should be always smooth. However, it may be difficult for beginners to keep pace with the speed. Then pluck up the courage and cut-and-try. The cost of falling down is not so big for XCD.

If you aren't aware, you can't anticipate either.

The information of terrain and barriers can be got by sight mostly.
Therefore you need to look forward carefully.
Easier said than done. Many skiers are seeing the area just a few meters away from the tips of their skis. To anticipate well, look farther but not too far.

If you wear heavy gear of plastic and metals, you could remain dumb and short-sighted. However if you're on XCD, be aware and anticipate to develop you skill fast.

[Johnny]

Don't fight against external forces.
If you wear heavy gear of plastic and metals, you could remain dumb and short-sighted

Love it! Thanks for the words of wisdom!

[Teleman]

E-Z Boys....Just because an individual picks that kind of equipment don't make him STU-PIT.....We lie skinny, pins, and camber....That makes us as STU-PIT as anyone else....Have been hearing of a shift to leather boots...back woods cruisers....and all that....Like that! TM

[CIMA]

Snippet 09: Turns (4 of )

What makes you turn?
Though many factors can be considered, it would be enough for XCD skiers to get the followings into mind.

• effective side-curves
• tension in the muscle

Effective side-curves

The effective side-curves are the resultant curves created by the following combinations:

1. the bent (negative camber) and sidecut of the ski
2. the front (lead) and back skis

1)

(Epic Ski)


(S. Shimizu)

2)



(S. Shimizu)

When the skis are angulated, they follow the lines of the effective side-curves like the tele-robots above do. However, in a precise sense, the skis derail the lines due to skidding.

Which type of the effective side-curves is more influential depends on the gear and ski technique you're adopting.

Tension in the muscle

When your upper body faces down the fall-line and you make turns with twisting your lower body right or left, tension is generated in the muscle and then the tips point the fall-line automatically as you release the tension



If you'd like to make your turns easier, face down the fall-line always.

[TeleMarcin]

Check it out:
http://www.fftv.no/fjellskiskolen-ep-1-skiteknikk-12

XCD by Norwegians

[CIMA]

Interesting!
His style seems to be a synthesis of traditional snowplow and jump turn techniques.
That works well on rough consolidated snow.

[Johnny]

Interesting, very interesting thread. Great information CIMA! Great vid Marcin!

We have a tele exercise here that looks like what this cool curly guy is doing. It really helps for certain people to get the idea of the tele turn. We, tele instructors, use it regularly here in Canada.

I remember when I started, I was trying to put one leg behind, to drop the knee. I tried it, didn't work for me. I tried everything for several weeks. When I finally figured it out by myself, I remember wanting to write a book, with a title that would sum it all: "Telemark, by Johnny: Put one foot in front of the other". (My original french quote is much cooler: "Le Telemark: CRISSER son pied en avant..."

I later realized instructors have already thought about it... Just like when I wrote my own time travel theory when I was 8 and realized later it was already discovered by some other funny guys and it was called "relativity"...

[Raventele]

Snippet 08: Turns (3 of )

When you descend the slope, check the following two points:

• Being aware of pressure in soles and external forces
• Anticipating the changes of external conditions

Sensing pressure in your soles is crucial.
You need to mind not only the difference of pressures you feel between right and left soles but also its distribution inside each sole. Since your movement is very flexible thanks to soft XCD boots, the information coming from your soles relates directly to your body position you're taking. Be sensitive to the changes of the pressure in your soles always.

Though I'm not going to describe the matters of physics in detail, it would be beneficial for you to know the following external forces acting on you.

• 1)
• driving force, or a force component of gravitational force
• reactive force you get from snow surface
• drag you get in your feet depending on snow conditions
• centrifugal force

First the driving force increases as does the angle of the slope. It is the force that lets you "fall." Don't be afraid of the force but cash in it. Advanced skiers know well that turning gets easier on steep slope than on shallow one. You don't have to turn proactively on the steep slopes: invisible driving force lets you turn.

Second sensing the changes of the reactive force from snow surface is important to tell the timing of turns. When the reactive force, such as buoyance in powder and repulsion from consolidated snow, is about to reach the maximum, that is the sign for you to initiate next turn.

Third the drag depends on snow conditions. If you ski on groomed surface, you feel little drag from snow. On the other hand if you ski on powder, you feel drags in your feet that would let you tumble forward in the worst case. The changes of drags caused by snow conditions can be sensed by your front ski as you make telemark turns. The drags may change according to the changes of hardness, lightness and stickiness of snow. The lighter snow gets, the more actively you can move.

Fourth the centrifugal force may not be a big issue because the speed of XCD is usually low.
Try not to angulate actively like you do on alpine skis or you'll fall down inside curving arc.

Don't fight against these external forces.
For example, don't make abrupt turns while the earth is wanting you to move along with fall-line. Transition from one motion to another should be always smooth. However, it may be difficult for beginners to keep pace with the speed. Then pluck up the courage and cut-and-try. The cost of falling down is not so big for XCD.

If you aren't aware, you can't anticipate either.

The information of terrain and barriers can be got by sight mostly.
Therefore you need to look forward carefully.
Easier said than done. Many skiers are seeing the area just a few meters away from the tips of their skis. To anticipate well, look farther but not too far.

2) If you wear heavy gear of plastic and metals, you could remain dumb and short-sighted. However if you're on XCD, be aware and anticipate to develop you skill fast.

2) Double down and tele on XC gear!
Our day out at Canmore Nordic started with terrible packed and icy conditions..And plenty of gravel here and there!
I could barley manage parallels on XC gear with combi-boots, and , of course, our Black Diamond poles kept collapsing (great for trying to skate hills!)! But as the storm raged and the snow makers roared , a couple hours into it and about 3 inches of fluff covered the sheets of ice..and yes, I could pull off some compact, tall teles..5 or 6 inches of the fluff would have been great, but , alas, one of us froze out! A little Tele on stock XC or skates can be great fun when the soft stuff falls on the groomed trails.





1) Centrifugal "force" is not a force..it's all about inertia/momentum.. I don't know what you mean by "drag" force on the boots..

[Krakus]

The second robot is demonstrating plow turns, not tele

[MikeK]

1) Centrifugal "force" is not a force..it's all about inertia/momentum.. I don't know what you mean by "drag" force on the boots..

Oh dear. This gets complicated.

Centrifugal force is a centripetal acceleration i.e. acceleration towards the center. Forces, positions, velocities, accelerations are all vectors. Vectors have magnitude and direction. So say for velocity, if the magnitude is constant and the direction changes, there must be an acceleration, because acceleration is the time rate of change of velocity. Such is the case motion along a curve at a constant speed (speed being the scalar magnitude of the velocity).

Because force = mass x acceleration, it was an age old practice to simply equate the fake centrifugal force to the centripetal acceleration acting on that mass.

And actually the force that causes this acceleration is directed toward the center of curvature as well.

The simplest case is constrained circular motion at a constant speed. In this case it can be shown (with a little vector calculus) that the centripetal acceleration is:

v²/r where v is the magnitude of the velocity (or speed) and r is the radius of the circle. This acceleration is purely radial, meaning that it points directly to the center of the arc at all times.

A force is required to keep the object along it's arc and provide this acceleration. This force also purely radial and points toward the center of the arc at all times. It is simply the previous acceleration times the mass of the object.

And yes it really does all boil down to momentum the purest sense. Dynamics by Newton's second law actually works such that the net force acting on an object equals the time derivative of the momentum, momentum being the product of the scalar mass, and the vector velocity. A force is need to change the direction of the momentum. The force is not centrifugal though, it is centripetal. It's often confused because lack of such forces causes objects to appear to move away from the center, they are merely maintaining their previous momentum.

If you are thoroughly confused, please study:

http://en.wikipedia.org/wiki/Circular_motion

It's actually all correct as far as I can tell, and very rigorous. You may need to brush up on your vector calculus though.