Quantifying Differences Between Men's and Women's Model Siblings

Tony S

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One of the many questions that can be probed more effectively by the amazingly informative new tool provided by SkiTalk member @AlexisLD is, "How different are men's and women's skis, really?" Taking a page out of @Noodler 's book I just tossed in a couple of sibling pairs to see what would happen. (Of course you have to work with the particular models and lengths that are in the database, so pure apples-to-apples is not strictly possible.) In this case it was Stormrider & Nela + Mantra & Secret. Bottom line, according to these numbers the Stormrider 95 and the Nela 96 are so similar in most ways as to be nearly indistinguishable. Both are middle of the road in bending stiffness and a bit above average in torsional stiffness. Their rocker profiles are also nearly identical. The Mantra/Secret pair is much stiffer, not to my surprise. (Always found the Kendos and Mantras planky. YMMV.) Interestingly the Secret appears stiffer longitudinally and torsionally than the Mantra in this length (170). (Assuming that this is by design, I'd speculate that Volkl figures that women on the 170 will be at the top of the women's weight range whereas men on the 170 would be near the bottom of the men's weight range.)

See the full analysis here.

Stiffness comparison:

1637675437905.png
 

Philpug

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AlexisLD

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That is awesome @Tony S! Great analysis. I would just remind you all that sub 5-10% stiffness differences are probably the results of "normal" manufacturing variations or the measurement process. I don't think I would try to read too much into the difference between the Volkl's skis. Such difference would also be hard to feel on the snow. The more and more we talk about it, the more I want to build skis with 5, 10, 15, 20%, etc. stiffness difference and put people through a blind ski test to see what they can really differentiate!

At the same time, the measurement of the Stormrider/Nela is also a great example of the best level of precision that we can expect from all of this. Measured stiffness are almost identical, even though they are two different skis that where likely produced by Stöckli and measured by Sooth at different time (and maybe on different machines and by different people).

You get the same kind of variations with measured weight. If you look at Blister reviews, where they weight both skis of a pair, you can often find difference between the two skis (50g, or 3-5%). These are accepted manufacturing tolerances. If the mass increased is all happening through increased thickness, that means that we can expect a 10-15% difference in stiffness (stiffness is a cubed fonction of thickness).

As Philpug pointed out, many other things can change between the men and women version of a ski (or scaling skis the length up and down). You can find manufacturers who change things and some who don't.

I think the real question is "what should change between genders and why"?!? There is a lot of marketing on this subject right now, but I wasn't able to find a clear answer to that question and different brand seem to have completely different strategies...
 
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Tony S

Tony S

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I would just remind you all that sub 5-10% stiffness differences are probably the results of "normal" manufacturing variations or the measurement process.
That makes sense.
 

Wendy

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That is awesome @Tony S! Great analysis. I would just remind you all that sub 5-10% stiffness differences are probably the results of "normal" manufacturing variations or the measurement process. I don't think I would try to read too much into the difference between the Volkl's skis. Such difference would also be hard to feel on the snow. The more and more we talk about it, the more I want to build skis with 5, 10, 15, 20%, etc. stiffness difference and put people through a blind ski test to see what they can really differentiate!

At the same time, the measurement of the Stormrider/Nela is also a great example of the best level of precision that we can expect from all of this. Measured stiffness are almost identical, even though they are two different skis that where likely produced by Stöckli and measured by Sooth at different time (and maybe on different machines and by different people).

You get the same kind of variations with measured weight. If you look at Blister reviews, where they weight both skis of a pair, you can often find difference between the two skis (50g, or 3-5%). These are accepted manufacturing tolerances. If the mass increased is all happening through increased thickness, that means that we can expect a 10-15% difference in stiffness (stiffness is a cubed fonction of thickness).

As Philpug pointed out, many other things can change between the men and women version of a ski (or scaling skis the length up and down). You can find manufacturers who change things and some who don't.

I think the real question is "what should change between genders and why"?!? There is a lot of marketing on this subject right now, but I wasn't able to find a clear answer to that question and different brand seem to have completely different strategies...
Is there a way to pick a point on the graph above to find a ski? In other words, if I’m looking for a ski with a lower bending stiffness but higher torsional stiffness, could I identify what ski that point on the graph refers to? Or can I work only from identified skis?
 

AlexisLD

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08298648f4cd94f81787b470771d6714.jpg

All of these women are 150lb. Should they all be on the same ski?

You mean ski length or model? Model is based on what you want to do. So easy answer is no, because they probably all have different aspirations.

Otherwise, are you talking about their differences in height? In mass distribution? In fitness? In skills? In style? Or in haircut? :) All these questions are also relevant for men.

How do you think skier height should affect ski length? And why?
 

AlexisLD

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Is there a way to pick a point on the graph above to find a ski? In other words, if I’m looking for a ski with a lower bending stiffness but higher torsional stiffness, could I identify what ski that point on the graph refers to? Or can I work only from identified skis?

@Wendy There is no easy way to do that right now, but we are looking into making the "click on a graph to add a ski" functionality possible.

The two ways you can use to do it right now are :
1. If you hover your mouse on a graph with the full database in background (gray and black dots), it tells you the name of the closest ski to your cursor. You can take note of it name/year/length and go back to the ski selection page to select that ski.
2. Alternatively, on the ski selection page, you can add filters to produce a short list of ski with given properties. You can also add as many columns as you want to this list (including stiffnesses). Using the added columns, you can then short the list however you want.
 

AlexisLD

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At the same time, the measurement of the Stormrider/Nela is also a great example of the best level of precision that we can expect from all of this. Measured stiffness are almost identical, even though they are two different skis that where likely produced by Stöckli and measured by Sooth at different time (and maybe on different machines and by different people).

I just realized that these skis have slightly different sidecut dimensions. They have very similar flex and torsional stiffnesses, maybe by design, but unlikely to come out of the same mold. They are not a good demonstration of ski manufactured with the same recipe at two different time that give the exact same result. They apparently have different cores, which would make sense given that the Nela is slightly larger but don't really show increases in weight or stiffnesses.
 

Philpug

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You mean ski length or model? Model is based on what you want to do. So easy answer is no, because they probably all have different aspirations.

Otherwise, are you talking about their differences in height? In mass distribution? In fitness? In skills? In style? Or in haircut? :) All these questions are also relevant for men.

How do you think skier height should affect ski length? And why?
A ski does not know how tall you are but can feel how heavy you are. Granted height can create leverage but it is a variable where weight is a constent. When I am considering a ski for someone who's weight and height are disproportionate, depending on the ski, application, aggressiveness and other variable I will err one way or the other, but usually lean to the weight side of the spectrum.
 
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