How are skis made? A 9-episode video series.

GregK

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Titanal in a ski won’t effect longitudinal stiffness but will affect torsional rigidity. You can run a partial sheet in the Center of the ski to improve dampening and it will have less effect on torsional rigidity vs having the outer frame of metal along the edges of the ski like Volkl uses on the Kendo 88/Mantra/Katana likes and K2 Mindbender. Outer frame saves weight Vs a full sheet yet you still improve dampness and torsional rigidity.

That’s why anyone who knows anything about ski building will tell you taking a round circle of metal out of the top titanal layer will do nothing for longitudinal stiffness and be unnoticeable on torsional stiffness too.
Have to change core thickness, core material, fibreglass weight, add carbon etc in certain areas for those changes that Peak talks about.
 

AlexisLD

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Titanal in a ski won’t effect longitudinal stiffness

This is not true. If you add titanal to any layup you will increase its longitudinal stiffness.

You can run a partial sheet in the Center of the ski to improve dampening and it will have less effect on torsional rigidity vs having the outer frame of metal along the edges of the ski like Volkl uses on the Kendo 88/Mantra/Katana likes and K2 Mindbender.

This is not quite true either. The "frames" are mostly done for marketing purpose and the compagnies keep changing their mind about which configuration is better!

That’s why anyone who knows anything about ski building will tell you taking a round circle of metal out of the top titanal layer will do nothing for longitudinal stiffness and be unnoticeable on torsional stiffness too.

Taking a round circle of metal out of the top titanal layer will change both the longitudinal and torsional stiffness at that location. There is just no way around it!

Renoun is not correct by saying that metal doesn't make a ski stiff. Yes, the glass and carbon fibres themselves are stiffer than aluminum, but the full fabric with resin is not necessarily stiffer and not in all direction. Also, often when you add metal to a ski you will remove some unidirectional fibre to try to keep the same bending stiffness and weight. However, as metal is isotropic, you will gain some torsional stiffness in the process. This is often the case, but doesn't need to be.
 

James

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This is not true. If you add titanal to any layup you will increase its longitudinal stiffness.
Are there any skis with the exact same layup except add metal?

There’s also the thickness of the metal that’s rarely mentioned, though early Kastle (the redo) gave the thickness of Titanal in different skis
 

AlexisLD

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Are there any skis with the exact same layup except add metal?

I am sure there are, but it is really hard to say by just looking at the measurements. But it is true that if you add metal you would probably also adjust the layup. However, you can adjust the layup to change or not the longitudinal & torsional stiffness. You can really do whatever you want.
 

Truberski

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Kind of makes you wonder if core material and thickness is better determinant of flex and feel of ski versus it having metal or not. There are so many light skis with metal today and they don’t really ski like the metal skis of yester-year. More like the metal is somewhat offsetting the use of thin/light wood core material but not delivering the feel ((dampness, suspension or whatever you want to call it).

Recent example for me was a few runs on my son’s J Skis Allplay skis (184 cm). Maple wood core with carbon/fiberglass and around 2000 grams per ski. The center mount and rounded edges from all the park stuff wasn’t my taste but what struck me was how smooth and calm they felt going fast through junky snow. Like a ski with metal but in this case likely from a heavier/denser wood and thicker core.
 

AlexisLD

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Kind of makes you wonder if core material and thickness is better determinant of flex and feel of ski versus it having metal or not. There are so many light skis with metal today and they don’t really ski like the metal skis of yester-year. More like the metal is somewhat offsetting the use of thin/light wood core material but not delivering the feel ((dampness, suspension or whatever you want to call it).

Recent example for me was a few runs on my son’s J Skis Allplay skis (184 cm). Maple wood core with carbon/fiberglass and around 2000 grams per ski. The center mount and rounded edges from all the park stuff wasn’t my taste but what struck me was how smooth and calm they felt going fast through junky snow. Like a ski with metal but in this case likely from a heavier/denser wood and thicker core.
They are all important factors and this is exactly why we measure the fundamental properties of the skis out there. Just listing the material used is not that useful. The snow doesn't care that you use metal, a maple core or carbon fibre. What is important is that the ski deflect a certain way under load, and that is determined mostly by its shape, bending & torsional stiffnesses and mass properties. You can use many different material & constructions, but if you keep these the same I guarantee that the skis won't feel too different...

Damping is also important, but all materials used in skis have very little of it anyways.
 

James

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I am sure there are, but it is really hard to say by just looking at the measurements. But it is true that if you add metal you would probably also adjust the layup. However, you can adjust the layup to change or not the longitudinal & torsional stiffness. You can really do whatever you want.
So the use of metal doesn’t necessarily make a ski stiff. That’s the point I think. Most people assume metal means stiff skis.

Got any specs on 1st gen Kastle FX 84, 94? Those had 2 thin sheets, not very stiff. I think that was 2013 or earlier.

How much do you think that the exact same build varies in stiffness. I.E., between different skis of the sane model/size. Wondering how much range one could get in stiffness just randomly.
 

AlexisLD

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So the use of metal doesn’t necessarily make a ski stiff. That’s the point I think. Most people assume metal means stiff skis.
Yeah, but is it really longer to say that you can make a ski as stiff or soft as you want with any material instead of saying "Metal does not make a ski stiffer"?!?

Got any specs on 1st gen Kastle FX 84, 94? Those had 2 thin sheets, not very stiff. I think that was 2013 or earlier.
No, started measuring around 2015...

How much do you think that the exact same build varies in stiffness. I.E., between different skis of the sane model/size. Wondering how much range one could get in stiffness just randomly.

Depends on the manufacturer, but what we seen from taking different pairs from the same rack is around 5-10%. It could be more if the core thickness is not controlled for carefully. The biggest difference is seen between years, when input material is often changing slightly. This is particularly true for wood core. Some manufacturers use certified wood (i.e., of specific density) to limit the changes.
 

GregK

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Lots of skis out there with similar construction in a lineup with metal and non metal options.
Remember the k2 Ikonic models that had very similar builds. Ti versions blending some lighter woods to keep weight down and non metal versions blending some heavier wood to try and dampen them a bit. The longitudinal flex was almost exactly the same, yet torsional rigidity WAY up and overall weight higher in the Ti versions.

Current Rossignol Experience line has Ti and Basalt options with that are otherwise the same construction. The Basalt versions are stiffer longitudinal and Ti versions again stiffer torsionally and a bit heavier.

Faction in the 22 CT line and the 22 Santa Ana both went the opposite way taking metal away from those designs. Faction dropped two sheets of metal underfoot found in the 21 versions and added carbon fibre weaves throughout the ski in 22 keeping the rest of the design the same. The latest skis are now stiffer longitudinal and softer torsionally where the metal sections used to be on the 21 version.

The 22 Santa Ana went from 2 full sheets of metal in earlier versions like the Enforcers line to only 1 partial width sheet of metal tip to tail with no core changes. Both the longitudinal and torsional stiffness changed very little on the latest version and only the weight dropped. The on-snow feel would be different of course with the weight drop.

So taking out a single hole in one continuous sheet of metal and changing nothing else will save about 15gr per ski and that’s about it. Lol
 

AlexisLD

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Lots of skis out there with similar construction in a lineup with metal and non metal options.
Remember the k2 Ikonic models that had very similar builds. Ti versions blending some lighter woods to keep weight down and non metal versions blending some heavier wood to try and dampen them a bit. The longitudinal flex was almost exactly the same, yet torsional rigidity WAY up and overall weight higher in the Ti versions.

Current Rossignol Experience line has Ti and Basalt options with that are otherwise the same construction. The Basalt versions are stiffer longitudinal and Ti versions again stiffer torsionally and a bit heavier.

Faction in the 22 CT line and the 22 Santa Ana both went the opposite way taking metal away from those designs. Faction dropped two sheets of metal underfoot found in the 21 versions and added carbon fibre weaves throughout the ski in 22 keeping the rest of the design the same. The latest skis are now stiffer longitudinal and softer torsionally where the metal sections used to be on the 21 version.

The 22 Santa Ana went from 2 full sheets of metal in earlier versions like the Enforcers line to only 1 partial width sheet of metal tip to tail with no core changes. Both the longitudinal and torsional stiffness changed very little on the latest version and only the weight dropped. The on-snow feel would be different of course with the weight drop.

So taking out a single hole in one continuous sheet of metal and changing nothing else will save about 15gr per ski and that’s about it. Lol

When they add / remove metal they also pretty much always add / remove something else.

Metal is in a sense irrelevant because you can get to pretty much any mass, bending and torsional stiffness distributions that you want, with or without it. But it is not accurate to say that it doesn't do anything.

Removing a hole in a continuous sheet of metal, if that sheet of metal is contributing to most of the ski stiffness and you don't put anything else in the hole, will significantly reduce the stiffness of the ski.
 
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Cyrus Schenck

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This is not true. If you add titanal to any layup you will increase its longitudinal stiffness.
An increase in stiffness comes from a higher second moment of inertia (I) due to the ski being slightly thicker due to the thickness of the metal. The increase in longitudinal stiffness due to the metal is marginal (as I note at 0:55s) compared to the increase in torsional stiffness and weight increase (which lowers the natural frequency and further aids in making a ski 'feel' stiffer). Does it make it stiffer on a mathematical level? Yes. Does it matter in comparison to the other factors that a human brain can detect? Nope.

There are many ways to slice and dice metal for marketing. Marketing benefit of a fancy metal cut > the mathematical benefits.

A cool graphic will change how a person perceives a ski more than anything. Just ask JSkis.
 

AlexisLD

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An increase in stiffness comes from a higher second moment of inertia (I) due to the ski being slightly thicker due to the thickness of the metal.

The young modulus of aluminum is 70 GPa, pretty much the same as fiberglass. This is not a soft material, and it is not just a spacer. If you add a layer of titanal that has comparable thickness to the fiberglass layer used in a ski, you will close to double the ski stiffness because you will have doubled the useful material at roughly the same distance from the neutral axis (that neglect a bunch of things, but it is clearly not "marginal"). If you don't want to affect the bending stiffness of the ski by adding titanal, you have to remove about the same thickness of fiberglass in your laminate.
 

Truberski

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A cool graphic will change how a person perceives a ski more than anything. Just ask JSkis.
Yes sir! My son has the “Bob Ross” graphic and he gets more attention and hoots than Beyonce! Personally, I’m a sucker for retro, wood grain, or all Black or White graphics.

Looking forward to what you go with for your 22/23 skis.
 

Scotty I.

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Non engineer (and not the smartest person) here. Please tell me if I understand this titanal issue using the following example.
The Fischer RC1 86 GT is pretty much known as a "big boy" ski and the reason for that (so I hear) is that it has two layers of .08 titanal. Further, it is often referred to as "Race Room" titanal. In other words, this is mega titanal and you had better bring your "A" game if you dare to try it.
But, in reality, titanal is nothing more than aluminum, it's floppy, and it does nothing to increase the overall stiffness of the ski. All it does is make the ski heavier and the increase in weight gives you a false sense of stiffness. Do I have that right?
This is going to affect some people as learning the truth about Santa Claus. I can't wait to go into a ski shop and the salesperson tells me that "these skis don't have just one, but TWO sheets of titanal. This baby is a BEAST!"
Hmmm well..... We need to talk".
 

AlexisLD

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Non engineer (and not the smartest person) here. Please tell me if I understand this titanal issue using the following example.
The Fischer RC1 86 GT is pretty much known as a "big boy" ski and the reason for that (so I hear) is that it has two layers of .08 titanal. Further, it is often referred to as "Race Room" titanal. In other words, this is mega titanal and you had better bring your "A" game if you dare to try it.
But, in reality, titanal is nothing more than aluminum, it's floppy, and it does nothing to increase the overall stiffness of the ski. All it does is make the ski heavier and the increase in weight gives you a false sense of stiffness. Do I have that right?
This is going to affect some people as learning the truth about Santa Claus. I can't wait to go into a ski shop and the salesperson tells me that "these skis don't have just one, but TWO sheets of titanal. This baby is a BEAST!"
Hmmm well..... We need to talk".

Not quite. Ski designers typically target a desired stiffness profile and plan their layup accordingly to acheive a desired on-snow feel. They can accomplish that using different materials. If they want to put titanal in a ski, they will typically remove other stuff so that the ski is not overly stiff.

Titanal is about 3x heavier than fiberglass by volume. Titanal is also isotropic, meaning its stiffness is equal in all direction (this is typically not the case with composites). Because it naturally heavier and isotropic, it is a bit easier to make skis that are heavier and stiffer in torsion. However, you can really accomplish any combinaison you want with composites (and materials in general). It would be easy to create a ski without titanal that is as heavy and as stiff as any ski with titanal. However, it is true that the name "titanal" is also regularly used by marketing departments to convey that a ski is designed for experts (stiffer and heavier).

Titanal is aluminum, but it is not "any aluminum". Aluminum stiffness is relatively constant regardless of the grade used, but what varies is its ultimate/yield strength (strength limit is when a material break). Titanal is about as good as you can get regarding its ultimate strength, so it will make the most durable skis. Titanal is also treated for bonding. Bonding aluminum is tricky and delamination is one of the main failure more of skis.

Being floppy is a terrible example that Cyrus is using to convey its points while confusing people. Any material in such a thin of a layer would be floppy. My mountain bike frame is made of aluminum and it is quite stiff (and light). Airplane wings/fuselage are also made of the same grade of aluminum as titanal and they are also quite stiff (and light).

The point is, you can find skis with almost any property made from almost any material. The material list is not a good indication of the properties of a ski because it depends how much you are using of each and how/where you are using them.
 

James

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Further, it is often referred to as "Race Room" titanal. In other words, this is mega titanal and you had better bring your "A" game if you dare to try it.
Pretty much nonsense. There’s no such thing as “race room titanal”. The aluminum alloy sheet trademarked Titanal and made by AMAG comes in different thicknesses. You can pick which ever. There’s a reason race skis use metal, but I doubt any current consumer available gs race ski approaches the stiffness of the race skis of the straight ski era that had no metal.

The RC One 86 GT is really impressive in it’s torsional stiffness, i.e. ability to hold an edge on steep solid snow. It’s not a beginner ski, and is probably best appreciated by upper intermediate to advanced skiers. But it’s not a punishing ski outside of that range. Just go demo it, even if you have your B game that day.

But, in reality, titanal is nothing more than aluminum, it's floppy, and it does nothing to increase the overall stiffness of the ski. All it does is make the ski heavier and the increase in weight gives you a false sense of stiffness.
Well it is more than just aluminum, it’s an aluminum alloy. It’s a bit like walking up to an airplane and saying, “that’s nothing more than aluminum”. (You can make airplanes out of wood too)

One of Titanal’s important properties is being able to bond with resins. The surface is treated for that.

Carbon fiber and fiberglass cloth is pretty floppy, and the wood cores used in skis would not support your weight probably by itself. The sandwich gets pretty strong once you bind everything together with resins.

Even big airplanes can be made of wood!

E9086682-5CD8-4659-AD4C-D1255B34CE64.jpeg

30CABF26-86B5-4816-A9D9-F455E0C07EB4.jpeg

Howard Hughes’s Spruce Goose, 1947
Made almost entirely of laminated Birch wood. Pretty impressive.

 
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GregK

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Agree that Fisher is just meaning “similar thickness of Titanal to what we used in our race skis” (usually at least 2 full 0.7mm plus sheets) but it’s the same material used in possibly thinner thickness in their other skis. Titanal goes from 0.3mm to 1.2mm thick so it can vary quite a bit. The .3mm versions are often used just underfoot for binding retention and would have far less effect on weight and flex Vs a thicker, full sheet running tip to tail.
Lots of all mountain skis using “2 full sheets of metal” may be 1/2 the thickness of the same companies race skis, so that’s why Fisher might be using the “race room” comment. Fisher also usually manufactures their race and higher performance skis at the Austrian plant Vs their Ukraine and might be another reason.
Skis like the Atomic Maverick, Faction Dancer, Peak skis and many others use 2 thinner Titanal sheets along with lighter wood cores, so they are not heavy or demanding like you might assume.

What Cyrus was trying to show and tell in the video is that an average thickness titanal sheet outside of a ski is not as rigid as most believe and it’s not the only reason some skis with metal can be stiff.
When you place metal within the ski’s ingredients to make the “sandwich”, titanal will effect stiffness but not as dramatically as most people assume. The manufacturer may be using thin sheets of metal for some extra weight and dampening but carbon sheets and thicker cores etc might be the larger difference between the stiffnesses of different models.
 

KingGrump

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Just go demo it, even if you have your B game that day.

...

Even big airplanes can be made of wood!

Dude. For some of us, even our A game is questionable. :ogcool:

And long before the Spruce Goose, they made them out of wood and canvas.
Let's all go and bring back the long straight skis. It'll be fun. :duck::ogbiggrin:

1657512066497.png 1657512021162.png
 
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