 Poster: A snowHead
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1) even edge bevel
2) sidewall degree of verticality
..and how these impact on how a ski skis..
And why does a ski with a sidecut of 121-73-105 have a radius turn of 12.9m at 161cm
and..a different make with a sidecut of 122-72-102 " " " 15.6m at 163cm
3) What makes a ski have a good edge hold ?
4) To get a good carving ski, is it better to have a narrower ski under foot, or can a wider ski be just as good, if the sidecut is correct?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| erica2004 wrote: |
| 4) To get a good carving ski, is it better to have a narrower ski under foot, or can a wider ski be just as good, if the sidecut is correct? |
I find a narrower ski is quicker/easier to get from one edge to another.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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I thought Carvers need to be somewhat fat tip and then become narrow, if the ski is completely narrow then it's more of a downhill ski no?
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1) Even edge bevel.
Each ski has 2 edges. If there is a bevel on both edges, then that is even. If there is only a bevel on one edge, then that is odd. If there is a bevel on 3 edges, that is very odd.
2) Sidewall degree of verticality.
It's slightly better than a Sidewall HND of verticality.
But seriously...
1 & 2 refer to the angle of the edge - between the base and the edge, and between the edge and the sidewall.
3 A ski has good edge grip/hold if the edge is sharp and stays that way. The angle of the bevel can improve edge hold, but increasing the edge angles can also have downsides in terms of wear, and requirement for sharpening.
4. Generally speaking, a ski that is narrower underfoot will be quicker/easier for switching edges (as rob says), but you need to consider where you will be using the ski, and how you want to ski it, because carving is not the only way to turn (nor is it always the best way to turn). There, I said it. Armchair experts/instructors feel free to disagree.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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erica2004, the side-cut describes part of an arc with the stated radius . . . but it's all a bit of bollux because as you bend a ski or board the radius shortens. It's your skill in edging front and rear that is a significant part in how tight a carve arc you can complete.
Edge hold is again, mostly within your control. good technique will allow you to carve a blunt edged ski where poor skills will spit you off a race prepared ski.
Your items 1,2,3 and 4 are really nothing to get anal about till you have a specific need to go really (REALLY  ) fast or turn on a silver thrupenny bit.
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You'll need to Register first of course.
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| Quote: |
Your items 1,2,3 and 4 are really nothing to get anal about till you have a specific need to go really (REALLY ) fast or turn on a silver thrupenny bit.
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So just buy the ones which match your outfit!
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| Quote: |
3) What makes a ski have a good edge hold ?
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The technique of the skier
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| Frosty the Snowman wrote: |
| Quote: |
3) What makes a ski have a good edge hold ?
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The technique of the skier |
On hard snow I find that a sharp edge makes a noticeable difference (although not enough to compensate for weakness in my technique).
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brian
brian
Guest
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Frosty the Snowman, rob@rar, both true, but torsional rigidity in the ski makes it easier.
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| erica2004 wrote: |
And why does a ski with a sidecut of 121-73-105 have a radius turn of 12.9m at 161cm
and..a different make with a sidecut of 122-72-102 " " " 15.6m at 163cm
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The space between the points on the long axis at which the ski is 121 mm wide and 105 mm wide is not 161cm, 161 cm is the "overall" length which may include a turned up tip or tail (though some makes do not).
Furthermore, there is absolutely NO guarantee that the waist is at the midpoint between the 121mmwide point and the 105mmwide point. For my own part, I consider the factory published radius label to be -more- accurate than the combination of stated sidecut dimensions and stated "overall" length.
So, in effect each of these measurements does actually say something but only within a limited context, for example (if the flex and waistpoint were identical or substantially similar ) that ski #1 has a tail that will engage more strongly at turn finish (thereby rounding up the turn instead of smearing it, thus shortening the overall turn size) whereas ski #2 has a tip that is more easily engaged to start the next turn. Ski #2 would thus be slightly more versatile under a skier that did -not- need the extra grip at the tail at the finish of the turn.
If I was choosing a ski, I would look at, in order:
waist size in broad categories (less than 75mm, 75-82mm, 82-88mm, 88-95mm, 95-105mm etc)
published radius
tip and tail measurements for turn shape
which length is appropriate for my weight and speed?
HTH
C
Edit:changed for clarity.
Last edited by Ski the Net with snowHeads  on Tue 11-09-07 18:24; edited 2 times in total
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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comprex, I thought the published radius was sidecut radius and not turn radius, as clearly turn radius will depend on weight, weight applied, etc. And will (should) change dynamically and progressively through the turn?
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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comprex, I thought the published radius was sidecut radius and not turn radius, as clearly turn radius will depend on weight, weight applied, etc. And will (should) change dynamically and progressively through the turn?
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David Murdoch, I am perfectly prepared to use the term "published radius" if you think it will lead to greater clarity. IMHO "sidecut radius" is misleading as is "turn radius" in the sense I used it above.
-changed-
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You know it makes sense.
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3) A good lesson
4) A good lesson
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Poster: A snowHead
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kiwi1, that's fair but, if we're really starting with a blank sheet of paper,
should include "+ a good boot" particularly for #4.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| kiwi1 wrote: |
3) A good lesson
4) A good lesson |
Have you forgotten that part of your day job is to sell skis? 
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Parabolas?
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v8, what about them?
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Where do you measure the waist at?
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You'll need to Register first of course.
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veeeight, I still do not know for sure what you mean by the question, but if you mean:
"If we make the assumption that the sidecut of the ski between point of maxium tip width and point of maximum tail width follows the curve of a parabola, and the further assumption that the ski is laterally symmetric, can we uniquely determine the position of the waist?"
then the answer is no, because we do not know which section of the curve the mfg. might choose to use other than the one centered around the axis of symmetry. As an example of this in other technology, see offset dish antennas.
Besides, Elan were about the only ones to actually use symmetrical parabolic sidecut curves.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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comprex, That was what I was getting at, furthermore, a few manufacturers are now touting "multi radii" sidecut skis, which has furthermore complicated the issue of x-y-z, nnm@160 measurements. 
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kiwi1, That's not entirely true, is it? Even I've noticed a difference between skis. veeeight, comprex, Then why do the ski manufacturers give these dimensions if they seem to be as unhelpful as you suggest?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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As a guideline. Not absolute. Test drive them yourself is the only fool proof way.
You could ask the same about boot flex figures!
Or estate agent measurements. Or car performance figures.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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| erica2004 wrote: |
| kiwi1, That's not entirely true, is it? |
Ammmm. Sorry Erica, whats not entirely true?.............oh sorry, just read through my posts. Yes good tecnique and a good lesson to help improve technique will always be very important. Many skiers on poor skis but with good tecnique and lessons under belt can hold an edge better than someone with poor tecnique and great skis.
But as you say there are many different aspects of a ski make up that help it carve or hold an edge. edge angles/how sharp, torsional stiffness throughout the length of the ski, side cut/TR etc etc but as there are so many skis on the market, this is why I'm an extreme believer of try before you buy because as you say, most people can feel the difference between skis.
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erica2004,
| comprex wrote: |
If I was choosing a ski, I would look at, in order:
waist size in broad categories (less than 75mm, 75-82mm, 82-88mm, 88-95mm, 95-105mm etc)
published radius
tip and tail measurements for turn shape
which length is appropriate for my weight and speed?
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I think this is as good, clear and helpful advice as you'll get wrt published dimensional or measured specification and ski choice.
As regards edges, spyderjon's site answers your questions very clearly.
Edited for clarity.
Last edited by So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much  on Wed 12-09-07 12:57; edited 1 time in total
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You know it makes sense.
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| comprex wrote: |
If I was choosing a ski, I would look at, in order:
waist size in broad categories (less than 75mm, 75-82mm, 82-88mm, 88-95mm, 95-105mm etc)
published radius
tip and tail measurements for turn shape
which length is appropriate for my weight and speed? |
I would humbly suggest that longitudinal stiffness (or lack thereof) is important too, though I realise that it's generally only available in more subjective measures.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| erica2004 wrote: |
3) What makes a ski have a good edge hold ?
4) To get a good carving ski, is it better to have a narrower ski under foot, or can a wider ski be just as good, if the sidecut is correct? |
Strictly speaking and all thing being equal (which they never are), a narrower ski will have better edge hold at the same edge angle. But theorectically, you can achieve the same edge pressure by heeling the plank over MORE, which requires more effort. For a big, tall skier, the difference between those two will be insignificant.
That's about geometry. But since skis comes in different stiffness, it often has more effect on the edge hold than geometry alone.
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Poster: A snowHead
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abc, I think if you get the length right then stiffness shouldn't really be an issue ? I think a ski needs to be torsionally stiff to give good edge hold but flexible enough lengthways for your height and weight. I've found exactly what you say though - a narrower ski is easier for me to turn.
comprex, For general all round skiing, would you say that it's better to have a waist of 70mm + ?
How about these :
Every Thang 122-72-106
Dynastar Exclusive Legend 114-75-102
Volkl Fuego 121-73-105
Burnin Luv 115-68-99
Stockli Spirit Ed 115-68-98
The Burnin' Luv has rave reviews for an all mountain ski - but is quite narrow waisted for off piste, but I did find it pretty good (in my limited capacity).
The Spirit Ed has rave reviews. What is it about the way the Stockli skis are made that makes them good?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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erica2004, I'm a bit nonplussed by this thread, what do you want? It's not possible (or I think right) to say one ski is particularly better than another, just simply because there are too many variable . . . most of which are you and your skills. You need to go and play on these skis and take lessons to have any idea of what suits your mind, your body, your skills level and where you want to slide.
The choice of ski is wholly subjective and subject to change as your ability, fitness and hill terrain changes . . . without you saying what those are it would be facile for us to make any recommendation.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Masque, Just trying to do a bit of research before picking some skis to try. I wondered what effect the different sizes/sidecut/makes/construction had on the way a ski behaved. I suppose I'm looking for something that I can buy and keep forever and I want a ski for my level that will enable me to improve but not be limiting. Most of you guys seem to want to buy fat skis to ride off-piste without a thought to how particular skis can help you learn and improve.
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erica2004, I ski on a 105mm waisted ski and that is my main piste ski also. I'm not going to get into the fat is better than narrow thing but, the skis I distribute are a very very small part of what is available in the UK and I wouldn't tell you to buy mine over anyother brand but, I'm more than happy to meet you at a snowdome somewhere so you can at least add/cross off the Icelantic skis from your list.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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kiwi1, That's very kind. 
I don't explain myself very well. I ended up buying buying Rossi B1s last year because they gripped better and were more stable than my C9s and they gave my confidence a boost. But in every other respect I hate them! The more I skied in them, the more they felt quite flat and boring. I don't want to make another mistake.
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try something with a wood core 
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erica2004,
The Spirit Ed sounds like a version of the B1 and I would expect the Stockli to be better. Otherwise, try as many as you can just so as to get a perspective of what you like in a ski and what you don't
It still means you have to demo though and can't really buy blind.
At 68 at the waist, it will be useful for new snow if it is not that deep although you might have to work them.
The Dynastar at 75mm and wood core sounds good
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| erica2004 wrote: |
| I ended up buying buying Rossi B1s last year because they gripped better ... than my C9s |
Anyone else a little surprised by this?
erica2004, I do not dispute your sensations, and the C9 was a rather disgusting shade of pease green, I just notice that it goes against the rules of thumb cited above:
114/74/104 (B1W) vs 104/64/95 (C9W) so, either by 'grip' you and I mean something different or there is another factor at play
(Significantly different ski lengths?* Edge sharpness?** Different tip and shovel flex therefore different tip pressure required to start turn?*** Different mounting points?**** Lower leg shape?*****)
I am not ignoring your question, BTW.
1. Notice that the waist of the C9 is narrower and therefore, by the above discussion, grippier when everything else is the same.
2. Notice that the tip to waist difference is about the same and therefore the C9 should turn into the new turn just as well when everything else is the same.
3. Notice that the waist to tail difference is about the same and therefore the C9 should give as much feedback exiting the turn when everything else is the same.
The 'stability' part I do not dispute. Finding the right ski for you that isn't flatboring and isn't a pocketful of squirrels will be a bit trickier than picking out mere dimensions.
What is going on in c's head:
* if the Rossis are shorter then your description of 'grip' might include 'wants to make sharper turns'
** Factory vs. ??tune
***the Atomic C series did have a somewhat stiff forebody, so that managing tip pressure at the start of the turn required more exact fore-aft balance and control
****Rossi mounted somewhat forward of the Atomic, so that turn entry is quicker?
*****If, when the knees are together, there is still a gap between feet a wider ski would bring the edge closer to the balance line of the body
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comprex, On icy pistes, skiing on the B1s, I never slipped. With the C9s I did, and my husband does. However, on good snow, I can do (I promise you) perfect carved turns. In fact in ski school I always had to give the demonstrations . With the Rossignols I can, but not so easily. The C9 just makes the carve and holds it, with the B1 I'm conscious of 'helping' the ski. However, the C9s are ladies 150cm and the B1s are men's 160cm. This is why I was interested in ski shape etc.
p.s. all the skis kept well tuned.
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