snowsport england ii 09 2013

8/13/2019 Snowsport England II 09 2013

1/58

How Skis Hold, and

Using the Inside Ski in Carved Turns

Ron LeMaster

Snowsport England, Sept. 2013

Ron LeMaster, 2013 1


2/58

How Skis Hold and Carve



3/58

What Makes a Ski Hold?



4/58


5/58

Putting a Ski On, On a Slope



6/58

The Ski Cuts a Platform



7/58



8/58



9/58



10/58



11/58



12/58

Platform Angle

The angle between the base of the ski

(the platform), and the balance axis

Not the same as the edge angle



13/58

What Determines Platform Angle?

Angulation Boot canting



14/58



15/58



16/58



17/58


18/58



19/58

Carving & Skidding



20/58



21/58



22/58



23/58

Platform Angle

The difference between carving andskidding

90 deg. or less, ski holds

Greater than 90 deg., the ski slips



24/58



25/58



26/58

Traversing and Turning

Platform angle is similarIts dependent on the relationship of the

CM to the base of the skis edge

Its independent of the slope



27/58

Traversing and Turning

What does this say about stance in aturn?

What does this say about canting?



28/58

The Inside Ski in Carved Turns



29/58


30/58



31/58


32/58

Using the Inside Ski

Best skiers use it to assist carving onthe outside ski

Primarily in first half of turn

Not carving on the inside ski

You must first learn to stand and

carve on the outside ski!



33/58


34/58

What Determines Carved Turn Radius?

Edge angle Higher edge angle = smaller radius



35/58

Edge Angle



36/58

Reverse Camber on Hard Snow

Determined by edge angle



37/58

P. Federolf, Finite Element Simulation of a Carving Snow Ski,

Swiss Fed. Inst. Of Technology, Zurich, 2005



38/58


39/58

What Determines Edge Angle?

Angle of lower leg to the snow, which isdetermined by

Inclination of body (balance axis)

Angulation

The distance of foot from the balance axis

(i.e., how much weight is on the inside foot)



40/58

Determinants of Edge Angle

Factor Range

Body inclination 0-70 deg

Angulation -10 deg

+20 deg

At high inclination,

range is reduced Ron LeMaster, 2013 40


41/58



42/58



43/58



44/58

To Make the Tightest Turn

Put only as much weight on the outsideski as you need to penetrate the snow,

make it hold, and bend into reverse

camber The rest should on the inside ski



45/58

Practical Limitations

Hard snow requires some force topenetrate

Human biomechanical considerations

Boot out



46/58

Get Your Feet Away From Your Body

Common advice for carving better turns Conflicts with the idea of standing on

the outside ski at the start of the turn



47/58


48/58


49/58



50/58

About 8 deg. difference in edge angle ofoutside ski

Outside ski edge angle 65 vs 57 (~8)

Carving radius 15m vs 19m (35m

sidecut radius on very hard snow)



51/58



52/58


53/58



54/58



55/58



56/58


57/58



58/58

William Nealy Ron LeMaster, 2013 61

snowsport england ii 09 2013

Documents