I believe Phil was just commenting on how the metric system is applied in the industry, and things that appear to be marketed as X mm, or Y cm, are not really X mm, or Y cm.
-
For more information on how to avoid pop-up ads and still support SkiTalk click HERE.
Scaling Construction and Dimensions in Ski Design
- Thread starter Philpug
- Start date
Wide, Medium, Narrow; and in some cases Extra Wide?
Take the numbers out other than length. That could be scaleable without the confusion of numbers.
Take the numbers out other than length. That could be scaleable without the confusion of numbers.
Thread Starter
TS
Thread Starter
TS
You mean like when the Rossignol Sky 7 was a 172 and the Sky 7 W was a 170 ... and they were the same exact ski?
I was thinking of my Nordica El Capo 185s that measure 188cm. But I figured you would have more examples.
Mfrs mislabeling skis is a whole different issue.
Skis should be referenced by some standardized, unitless, unmeasurable quantity. It works for boots.
I think that IS the issue we're talking about, with the tongue-in-cheek jabs at the metric system.
Scratches head.... don't think this is the case.
Grab a ski and put it down flat on a table. Put whatever weight you want on it and it will not bend.
Tip the ski to a good edge angle so only the tip and and tail are in contact with the table. Press in the middle and only a small amount of force - a fraction of body weight - is required to bend the ski so the middle also touches the table. Once the middle contacts the table pressing more - representing a heavier skier - will not bend the ski any further. The only way to bend the ski further is to increase edge angle.
So, no, it's not "energy required to bend the ski" - it's edge angle.
Ever try to tip a ski without adding weight to it? Of course it bends as soon as you click into the bindings , it starts by decambering. then, as you tip to an edge, you are putting energy into the ski, its bending as the tip engages and bites the snow, as you come across the turn, the rest of the ski is bending as energy and forces build. when you release the edges and you COM changes direction, the ski energy releases, and flexes again. this exactly why I like cambered skis.
Last edited:
I gave this a lot of thought before I wrote something about Augment's claim that they can custom build a ski to ten stiffness specifications on order.
My conclusion was that I didn't think that could be reliably done for a number of reasons.
Part of the reason I concluded this is the materials like fiberglass and high tensile aluminum sheet are not available in small thickness increments.
The cost of custom weaving and rolling is prohibitive so making a ski in small, discrete stiffness increments under manufacturing control is very unlikely.
CNC milling a custom core profile for each ski length and model is a production nightmare for skis costing $1600 or so.
I'm not sure that core thickness adjustments alone without scaling layup materials will do the job.
But, as to the question proposed by Phil, there is another issue.
Scaling resonant properties and stiffness at the same time would be very tough even if you knew what you wanted to do.
I do believe that the vibratory properties of ski models is the magic variable that makes some good and some stinky.
If you get a ski in the prototype length it will probably ski as tested.
Get far off the prototype size and I think things get chancy without actual on snow testing.
My conclusion was that I didn't think that could be reliably done for a number of reasons.
Part of the reason I concluded this is the materials like fiberglass and high tensile aluminum sheet are not available in small thickness increments.
The cost of custom weaving and rolling is prohibitive so making a ski in small, discrete stiffness increments under manufacturing control is very unlikely.
CNC milling a custom core profile for each ski length and model is a production nightmare for skis costing $1600 or so.
I'm not sure that core thickness adjustments alone without scaling layup materials will do the job.
But, as to the question proposed by Phil, there is another issue.
Scaling resonant properties and stiffness at the same time would be very tough even if you knew what you wanted to do.
I do believe that the vibratory properties of ski models is the magic variable that makes some good and some stinky.
If you get a ski in the prototype length it will probably ski as tested.
Get far off the prototype size and I think things get chancy without actual on snow testing.
Waist width and turn radius are equally concerning, as are stiffness and damping ability.
Damping ability should be the same (i.e. good for the speed and conditions the ski is designed for) across all lengths.
Length will never scale perfectly, as it and flex resistance should be scaled (to provide the same size of turn at the same speed with the same degree of tipping) to mass and skier height, but will also regardless of scaling give a smoother ride with a longer length. Tipping effort will always be more noticeable with a wider waist width, so not much hope there, although not much of an issue for softer snow.
Width is a tricky one, besides the tipping effort mentioned above, there is the float factor which works to make wider skis floatier, but also makes them seem to want to go faster in soft snow.
poor marketing, Augment doesnt actually claim to do this. Its explained better somewhere in their Euro site, (I think I quoted it on my Augment 77 review) but they are really relative flexes. thats why now they just make 3 levels now but my understanding is that its pretty much based on the technician's feel for flexes. This is like when a pro/Natl Athlete takes 10 identical race skis up on the hill and then chooses a few based on how fast they and/or feel the best. I've skied a few different flexes and honestly cant say the difference was dramatic between a 8 and a 5 (for instance). I think Phil skied the "flimsy" version, 10 which was about the same flex as a Brahma, Im on a 8 and its quite stiff as well.
Last edited:
this. Put a 6' tall 140 pound skier on a 184 and the ski will ski significantly different than the same skier on a 177. Head monster 177 vs 184 comes to mind. if you didnt have the mass and energy to bend that ski, it was a handful. But yes, the greater the surface contact on the snow, the more stable (in general)
Thread Starter
TS
Yes, they are important but the selection process starts with the waist width. Walk into any ski shop, look how the skis are displayed on the wall. It is either by brand and their collections or by waist width. There is not a ski shop in the world that displays skis based on radius, stiffness or damping.
the clash of marketing vs consumer education? But we all are guilty of this to different degrees.
Last edited:
A ski length being mislabeled with a standard unit of measurement is a far cry from saying skis should be arbitrarily labeled soft/medium/stiff in a scale that has no standard.
OK, we're talking past each other. I didn't realize you were referring to the "soft/medium/stiff" scale.
- Joined
- Dec 2, 2015
- Posts
- 24,847
Well for a purely carved turn on hard snow.
You can bend the front more , and the rear more in sliding somewhat while on edge. Most common example- on steep 3-d snow, soft skis with an aggressive skier will “fold up” or bend too much causing a dramatic slowing. I guess the same can happen in carving mode, where the bending is not just proprtional to the edge angle.
Noodle skis are slower, and will force you to ski slower, even if carving. Often you don’t realize it if you get used to a soft flexing ski, till switching to a stiffer ski with similar sidecut. Why?
It's too easy to fold up a softer ski when you're expecting a given resistance (e.g. you switched skis at lunch time)when carving clean turns. What happens is you end up having the ski bend into too tight a turn and try to follow a line it can't hold. Then bad things happen.