Ski thickness

[Wish]

how does ski thickness affect performance????? Just tested an HO Coifficient Xsl. Set it next to an A2. Biggest and most notable difference (aside from step bottom) is the ski thickness. By the way JTH is right on with his review of this ski. Don't overlook it because it's less $$. Is thinner just a byproduct of layup materials being stronger or does a thinner profile change the way the ski works??

[Horton]

Thickness is huge. When I get some sleep (sober up) I will see if I can write something semi-intelligent on the subject.

 

More important, the A2 and the COX are different in many other ways.

[eleeski]

I've tuned skis by adjusting the thickness of the ski. It is an important factor in ski design. I can't say exactly what it does for every ski though - or where it should be thick or thin. The edge at the top of the ski also matters a lot - and is something that can (should?) be (gently) filed on on many factory skis to make a consistent parting line.

 

I did ride a ski with little wings on the top of the tail. That helped keep the tip down. Hmmm, maybe I'll add those to my ski for Regionals!

 

Eric

[Wish]

Bump. @Horton. ... You "sober" yet??

[Horton]

As a ski gets thicker the sidewall holds it up more. A over thick ski under the bindings will roll over as the side wall creates lift and keep rolling until you fall in. A thin ski will ride a little deeper in the water.

 

All of this depends on where the thickness is. If a ski is thinner in the tail the ski theoretically will ride deeper in the tail.... all of this allows the designer to adjust the skis attitude in the water... Thickness is one of many things that affect attitude.

 

Screw it .... will someone smarter than me explain all this? All I can tell you is that if the factory screws up and makes a ski a little too thick you it will suck. Happened to me once.

[matteoianni]

You are smart enough, Horton! That was a good explanation.

[tap]

I've been reading your forum for a bit, finally decided to chime in on something...

 

I don't know too much about how thickness effects the hydrodynamics (so I found your comments rather intriguing), but I can share some thoughts on how it effects structure. I might be stating the obvious here, but thickness has a direct effect on the stiffness of a ski.

 

Ski construction is typically a basic cored panel: fiber reinforced composite top skin - core material - fiber reinforced composite bottom skin. This panel forms an "I-Beam" structure. As the ski is flexed the top skin goes into compression, the bottom skin goes into tension, and the core goes into shear with the neutral axis somewhere near the middle. To simplify beam theory... stiffness is a cubed function of beam thickness. So a little bit of thickness, either added or removed, has a rather large impact on stiffness. Not to mention removing unnecessary material sheds weight. I assume this is why there's quite a few slalom skis out there with very thin tips, trying to shed weight up where stiffness is not as important. Or maybe it's just good marketing...

 

~tap

[thager]

I show my ski how to run the course over and over and over again but it doesn't get it. Must be too thick, just like its owner! Amazing how thin a glass o Beam makes your ski feel! Cheers!

 

[eleeski]

Tap, the weight of the core is minimal. You are right that the thickness of the ski greatly affects the stiffness. But graphite is so stiff that you can make a stiff thin ski. Plus there are some other tricks to affect stiffness and still present a thin edge to the water.

When you turn, the side edge is essentially the bottom of the ski. The attitude of the ski is greatly affected by the thickness of the ski. It all factors into the feel of the ski.

I put the top wing on the tail of my ski for Regionals. Maybe it worked, I ran my 32off. But I still got a ton of slack on my good side. I might need to take a grinder to the ski. Change my style? Get serious.

Eric