What is the deal with ski sizes? How is each size created?

[Horton]

Every ski company does things a little differently. So what is stated below are generalizations and do not exactly reflect any one manufacturer.

 

At the start of the development of a new ski there is only one size. Depending on who the key R&D skiers are, the new ski is most likely the size that you would expect for a 66” ski. Companies like Goode who use a different sizing metric make this a little confusing but the point is that the “Mother” ski is the preferred size of the test team skiers.

 

The R&D team will spend months or even years experimenting with shapes, flexs, rockers, materials and other secret stuff. When they are done they have the “Mother” ski. The important point here is the team will not have so much designed a size. They will have designed a ski that works for them. You could call it a 66”, 67” or a 65” or whatever.

 

They then must decide how to make the bigger and smaller sizes. In the CAD software the designer could simply increase or decrease all dimensions proportionally. This is called “scaling”. In most cases the new sizes are not exactly scaled off of the Mother ski. As the new sizes are developed the designer may choose to make one size proportionally wider or narrower than the next or not (or change any other dimension). In some cases each size is almost redesigned from scratch.

 

Why not just proportionally scale all of the sizes? One reason is that slalom skis are made up of numerous compound curves. Some of these curves can be proportionally wider or narrower without altering their function and some can not.

 

Theoretically the Mother ski should be the most developed and the best of the sizes but this is not always true. I can think of at least one example in the last 5 years where the Mother ski was arguably inferior to the larger and smaller sizes. In other cases the different sizes of the ski are noticeably different but not necessarily better or worse from each other.

 

The physical length of the ski and the official length used to describe the ski may not match. As the ski becomes a finished product the design team has to decide what skier weight and speed range will fit each size they have developed. Perhaps it is more likely that they develop sizes based on anticipated skier weights and boat speeds. When skis are sold in ½ inch sizes this is often the factories way to saying the ski falls between the typical sizes.

 

The actual length of the ski from tip to tail has next to nothing to the skiing size of the ski. If all other factors were the same and you knew the square inches of surface area behind the front boot you would have one data point but this would not tell you what size ski you should ride. Ski sizing is about more than pure surface area of ski. As an example, if the designer changes the flex and rocker of the ski and nothing else the skier may need to move up or down in ski size.

 

So how do you figure out what size ski to ride? First of all, most factory size charts are generally pretty good. Whenever possible you should demo a ski before you buy it or look for skis that have a return policy. I strongly recommend dealing with high end ski shop the like Performance or factory direct with brands like D3 or Goode. When you buy a ski from your local boat dealer you may know more than they do. Even if they cut you some sort of deal, you risk not getting the best ski for you needs.

 

As a side note any time you try a ski with non-stock fin or binding settings you have totally change the equation again.

[Razorskier1]

This is so true. I was told when I bought my old blue and red Sixam that the 69 was the mother ski. I bought a 69 and loved it.

[gregy]

I've always thought height of a person played a role in ski size. If the body is a lever applying tip or tail pressure on the ski from the COM. The taller person can apply more torque to the ski.

 

Seems like I'm always on the fence at 190lb between 67 and 68.

[Horton]

@Razorskier1‌ I do not know about the sixam but that sounds unlikely

[gregy]

@horton I figured the skis were made using a scaling type method. Is there something done similar with fin settings. Like when you see something about Rossi's settings and it's listed for 65, 66, 67, 68 etc. I can't see him skiing all sizes and even if he did the # wouldn't work for person of proper size for a ski. Maybe a chart using extrapolation?

[Horton]

@gregy‌ I sure @chrisrossi‌ and the Radar boys put a lot of time into those settings but that is a really small task compared to the actual design process.

[Razorskier1]

@Horton -- heard that from Austin Abel. Bought the ski directly from Mapple way back then.

[Horton]

@Razorskier1 odd but I believe you

[ozski]

Warp comes in any length as long as its 67 - lots of different sizes and shapes ride that ski. Its an interesting topic because I've just dropped from 67 to 66 and my scores are about the same but I like the 66 a lot more and think I can take it further. To me 66 Helix feels faster than 67 Quest.. I'm 175 - Moral of the story is try before you buy if you can, don't get any particular length stuck in your head and keep an open mind, we could all be skiing on stable, lightning fast 62 inch skis in a few years..

 

 

[Horton]

@ozski‌ the work maybe 67 inches long but with the bindings at 28 1/2 it does not set the standard template at all