A question for old pin-heads...

[mountainmandoug]

So I have a question for those who have been teli skiing long enough to know about such things.

 

I picked up a second-hand set of skis today and stuck some three-pin binding on to try them out (they had the holes already from the previous owner). I noticed that they had a tendency to tip-dive more than I am used to. I'm fairly sure that the binding is mounted in the conventional place. I have a set of wedges designed to mount under a three-pin or other flat telemark binding, which I have read were created to help this problem. I can't figure out how they would help though, it seems like they would just push the tip down more.

 

I suppose the other thing that might help would be to re-mount with the bindings either forward or back a bit?

 

Any advice would be appreciated.

Edited April 13, 2010 by mountainmandoug

[johndavidjr]

tip should fall slightly.

[ScottP]

Your problem sounds like rocker launch.

Tele boots have a tendency to rock the skier forward due to the "rockered" nature of the boot design. You can see this if you put your boot in the binding. Most likely the heel will not be setting on the heel piece, but will instead be hovering above it.

This effect can cause you to be pushed, or "rocked" forward toward the tips of the skis, causing the tip dive.

The wedge is supposed to offset this effect by lifting the front of the boot up and setting the heel down.

As you mention, tip dive can also reduced by moving the binding back a bit.

[ghani]

tip dive can be a few things.

 

A skinny a ski in powder can stuff a tip easily, especially if you ski with a "one footed" technique. Too far forward a mount position is usually the cause of tip dive if the ski's width is appropriate for the snow depth and your technique is good.

 

Wedges help with "rocker launch" by angling the front of the binding upward to compensate for boots that have developed a rockered shape with age. Wedges also reduce the "dead spot" in the boot's bellows resistance when the boot shape becomes rockerd and the boot gives no resistance until the heel is far off the binding heel plate. Wedges help give earlier bellows resistance, but would cause even more tip dive than you already have.

 

If this ski is a hardpack ski, (less than 80mm underfoot) and you are skiing deep snow, it's likely that you are just stuffing a tip because the ski lacks floatation and the boot/binding combination is not active enough to counteract the rotational forces of the ski's resistance so you are launching over the handlebars.

 

What ski are you talking about here?

 

A good check for binding postion on a traditionally cambered tele ski is to lay the ski on the floor and put the boot in the binding. The ball of foot of the boot should be about in the middle of the distance between where the tip and tail points of the ski contact the ground. You can cheat forward 1cm for hardpack ski mounting and back 1-2cm for deep snow mounting.