equipment

Question
QUESTION: I have been skiing for 15+ years and will be in need of new skis sooner rather than later (they are older than I am).  I have never skied on shaped skis and needed some direction regarding size.  I am 25 years old, 161cm tall, 105lbs, Ski-LL level 8, and have been skiing on the same 170s since I was 10 or so.  I appreciate any direction you might have on the subject.  Thank you.

ANSWER: Hi Blair,

Welcome to the new world of skiing. One question. Is the 105 lbs correct? Also before I answer this question I'd like to suggest that you read some of my other responses on similar matters before we nail down any specifics. Not only the ski equipment has changed but the technique that they allow can be radically different form what you have experienced before. I'll wait till I hear back before going further.

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QUESTION: Thank you!  I must admit, the new world scares me a bit!  I fear I might cry when I berid myself of my beloved Heads...

I think I read most of the other relevant answers (Paula's question and answer was particularly revealing), and it seems like the length is not the main thing I need to worry about.  Rather, I should be more concerned about radius?  It seems to be a matter of striking a balance between stability, control, speed, et cetera along with being an issue of weight.

I ski almost exclusively on groomed trails (off piste once or twice in Colorado) with long, fast turns.  Ive sort of gotten out of the habit of really carving, but I tend to keep my weight farther forward and try to tip up on edge when turning.  

P.S. The weight is correct.

Answer
Hi Blair,

That really helps. Just a couple more questions and then I can make some recommendations:

1) are you male or female? (can be relevant to the type of ski or its mounting point) I assumed the later.
2) how athletic a style do you prefer or do you want to experience: dynamic at all speeds where there is a reaction from the equipment that helps propel you down the slope; easy cruising, more a floating feel and a sensation of easy transition from turn to turn when possible; something else?
3) Can you estimate the length of the turns you describe as long and do you have a desire to shorten this ever? Can you give a guesstimate on the average speed you ski at (what's fast?)

As to your first implied question- radius.

Depending on the type of ski, its length, radius and its torsional characteristics carving can be easily accomplished with most modern (though not all) equipment. As the industry has segmented the market into the many categories of skis (think of a continuum from racing style and technique to big huge floating powder turns or on the outside even further the slopestyle equipment used for terrain parks) not all shaped skis work similarly anymore.

The description of how you initiate your turns (weight forward, tip on edge) is in its essence the start of a modern turn. The problem we encountered in the past was that because of the technical limitations of the equipment of the time the reaction of the ski to this was limited and did not result in a rapid enough tightening of the arc to get a edged and arced (what is generally referred to as carving) turn engaged easily. Skiing at its highest end on hard snow was always dependent upon strength, power and perfect timing which left most of us out of the picture and allowed our skis to slide much more than they gripped. Interestingly product designers knew since the early 70's that sidecut was one part of the puzzle to prevent the skis from slipping. If you increase sidecut in a ski once you tip it on edge it will want to follow the arc or path that sidecut defines (the radius)and begin to carve. At the same time the ski had to bend longitudinally and twist in order to maintain contact with the snow. The problem was that this increased the torsional forces on the ski and at the time they did not have materials available to deal with this so if the sidecut was too great the ski would become torsionally weak or soft and just release (slide). Speaking from personal experience while this problem was being worked on (some manufacturers made the whole ski softer so that it would bend more) some pretty awful skis were made before the whole thing (some pretty expensive stuff could feel like skiing on noodles while others had the reaction of two by fours) was resolved.

One last point. The earliest shaped skis were with primarily a parabolic arc. Like an hourglass the concept was to create a round turn on edge, what most skiers still think of as a carved turn. Most modern skis that can carve have a combination of radii built into them. You can see this from the dimensions built into a ski and shown on the ski. Usually the sidecut at the front is much greater than at the tail. Thus the turn shape is not truly round. If for example after tipping the ski on edge you begin to resist the buildup of pressure under foot by moving the body inside the arc and away from the edge (which bends the skis more) the resulting reaction can lead to acceleration and a rebounding effect in between turns.

What has really changed about modern equipment and the skiing that has evolved as a result is that on the the old equipment balance was primarily vertical (up and down) and horizontal (fore and aft) whereas now in addition the lateral (side to side) plane and rotational are involved to a much greater degree. I have attached two website links for you to check out.

http://www.sportskool.com/videos/better-turns

http://www.manitobamastersskiclub.com/Technical%20Videos.html

The first is a breakdown of what helps you to carve a modern ski and if you click on the second web link and go to the first two videos you can see this applied in both a long and a short radius. The environment mimics what I think you spend your time on (groomed)and the videos show the potential of some of the equipment available.

Now Length

Length required will be a function of your speed as well as your personal characteristics (weight, height, centre of mass, etc.). At your weight and height (which influences the leverage involved in the fore aft plane talked about in the first link) usually for a ski to be versatile or general purpose you would be looking at no more than 145-55 cm and a 12-14 m radius. If you were looking to increase the radius of the turn in the 15-17 m and above radius you would probably be looking at a ski around 160-165 depending upon speed. Your weight could also indicate that you would benefit from a junior race ski rather than an adult ski depending upon your boot sole length (what size of foot are you?) and these can be shorter yet.

We require nowhere near the same lengths as in the old equipment because the stability of the ski is primarily dependent on its ability to grip the ground and arc. For example what was previously seen as the average length for an accomplished male skier (195-205 cm) would today be found only on skis intended to go above 45-55 mph and the turn shape or type of speed (15-35 mph)that these were designed for in the past is usually accomplished by skis as much as 30 cm shorter.

Now here's the bad news. All ski performance is affected by your boots far more so than in the past. If your boots don't allow for good balance (look at the  bending in the ankle joints in the first video)and a well timed application of force while helping you increase or decrease pressure on the ski while still achieving balance in the lateral plane the results aren't the same. Most modern boots are made with this in mind though.

Get back to me if you need more info. Glad to help.