HOW does sandwich construction influence ski perf & PMTS

[40below]

HOW does sandwich construction influence ski performance & PMTS progress?

Since there are several on this forum who have owned &/or played both Head instruments:

- SuperShape & i.SL -

would you kindly explain HOW the sandwich construction used in the SuperShapes (& other RD race products)
differs from X-frame or whatever type construction is used in the i.SL for example;

and even more importantly, HOW & WHY it makes the ski perform differently?

Then, WHEN is it more desirable to choose one instrument over the other?
(Strat vs Les Paul, Titleist vs Calloway, etc.)

TIA !

@40below

[John Mason]

I have 4 pairs of head skis. The I75M is a cap construction. The 1100, 1200, and SS are all of the laminate construction.

The laminate construction makes for a very progressive - bow and arrow like - response to pressure changes. The first time I skied on the 1100 and felt this and how well the ski hooked up I got a smile plastered on my face.

I've also skied had 6 stars and nordica's. They were both cap construction though the 6 stars modified that with their imbedded rails. The progressive nature of the laminate construction is quite a noticable difference.

I also skied with race stock Head WC skies at the hood camp in June and they were much too stiff for where I'm at in my skiing.

[SrMike]

Over the last 3 seasons I have skied a Head XRC 800 in a 177, the Supershape in a 170 and the i.SL VIST RD in a 166. I have also been on quite a few demo skis. I guess the best answer I can give to your question based on my experience is ski selection depends upon skiing ability and how fast you are capable of progressing as a skier.

In my case I just so happened to be on a the XRC 800 when I found out about PMTS. Last year as I felt I was progressing I got the Supershape. The Supershape was less forgiving, but is capable of an order of magnitude more performance. The i.SL RD is an order of magnitude or 2 more ski beyond that.

I really don't know why X-Frame construction / cap ski is different than a sandwich construction or vertical sidewall ski. I have been told that cap skis are less expensive to produce and are easier to produce in mass quantities. It's easier to customise sandwich ski, which is why most race skis are sandwich construction. (Note: Atomic race stock skis are cap construction)

In my case the reason I got the i.SL RDs was I noticed when I skied FIS slalom race stock skis they are very sensitive to for/aft pressure and have a very narrow sweet spot. I wanted to get a ski like this to learn to be more centered over the ski. I happened to get the Head i.SL RD because I got a pretty good deal on them. I had it down to Elan, Head and Fischer. Since I've skied the i.SL RDs a few times now, I am a lot more centered skiing the Supershapes. The step up from the XRC800 to the Supershape was similar.

I get a great workout on the i.SL RD. You have to be there 100% of the time or the ski will bite back hard. OTOH, what the i.SL can do is really amazing when used in the conditions for which it was designed. 2-3 hours skiing hard on the race stock ski is like all day on the Supershapes. The XRC800s feel pretty wimpy to me now. However, under certain conditions, I would still ski the XRC800.

[40below]

Thanks guys, this is exactly what I'm looking for,

especially the discussion around a very common ski progression that is often recommended here in order to develop PMTS carving skills :
XRC800 or i.M72 > i.SL > SuperShapes .

(All Mountain/Powder equipe'/1-SQ being another discussion altogether)

John, the bow analogy is perfect, and that's what I suspected-
that the laminates store and release energy extremely efficiently with the least energy loss vs. other construction methods.

Now for a slightly different twist for "you'uns" who've made substantial progress:

*****From your current skill levels, knowing what you know now,
what would you do differently (if anything) with equipment selection as you progressed, and why?

thx ~

[Ken]

I think you mixed your ski progression...the SuperShapes are more versatile while the i.SL have higher ultimate performance.

Ski length is often not optimized, usually too long. Binding position is very often not considered. Don't rely on the manufacturer's markings. The SuperShapes do very well with the boot center 10 to 15 cm forward of the ski mark, and maybe farther forward (???).
Interesting info:
http://www.lous.ca/Articles/Biglines%20article%203.pdf
http://www.lous.ca/techarticles.htm


Ken

[Max_501]

Binding position is very often not considered. Don't rely on the manufacturer's markings. The SuperShapes do very well with the boot center 10 to 15 cm forward of the ski mark, and maybe farther forward (???).

When considering the CP13 plated skis, I think this may only be true for boots that are 28 or greater in size. My boot is a 27 and all of my CP13 plated skis (I have 3 of them) ski great without moving forward.

[Ken]

Could be. My SS skis have railflex bindings. I set my 335 mm boot soles 15 mm forward of the mark for packed snow and on the mark for unpacked snow. They do ski very well on packed snow on the mark, just better forward of the mark. Harald is the one who told me about the SS skis doing well 10 mm fwd.

About SrMike's use of very demanding slalom skis for his training...that is either a very astute training idea, or somewhat akin to learning to juggle knives so you'll be able to juggle raw eggs in the future without dropping one.

Ken

[SrMike]

About SrMike's use of very demanding slalom skis for his training...that is either a very astute training idea, or somewhat akin to learning to juggle knives so you'll be able to juggle raw eggs in the future without dropping one.

ROTFLMAO That is an interesting analogy.

I wouldn't go quite that far. It's just a step or two up from the Supershape. If I thought after skiing FIS SL demo ski that it was more than I could handle, I wouldn't have done it. The thing is, the ski responds very positively to PMTS movements.

I think the point is to get a ski appropriate to your ability that will respond positively to PMTS movements. In many cases that may be a ski that is a little more challenging than you expected.

[40below]

About SrMike's use of very demanding slalom skis for his training...that is either a very astute training idea, or somewhat akin to learning to juggle knives so you'll be able to juggle raw eggs in the future without dropping one.

Precisely! When my golf pro convinced me to get some high quality Wishon forged blades (plug! for Tom Wishon Golf of Durango, Co.), matched with the appropriate freq'd shafts, my handicap plummeted 5 strokes in a very short time due to the ummm, immediate / direct harsh feedback from the mis-hits, and by contrast the rich reward of smooth butter, baby! when I struck the ball well.

But then, I had the motivation/discipline to persist and to practice daily/intensively in order to elevate my game, same as with skiing now.

So let me ask again (or do I need to post as a new topic),
from a more advanced skills point of view, what would you do differently (if anything) with your equipment progression, and why?

i.e. - could you have chopped off a little more of the learning curve,
perhaps bypassing an in-between ski, with more of . . . . . . . whatever?

[SrMike]

In my case - the answer to your question is no I would not change any of my recent equipment decisions.

I was out of skiing from '89 until '03-'04. I learned to ski in '77 and I ski patrolled from '79-'84 in Ohio and 3 weekends at Eldora when I moved to CO in '84. Back then I was on straight skis using old school technique. There were a couple of years in there where I was in pretty good shape and I could ski just about anything.

In '03-'04 I got a pair of Rossignol Cobra T-Powers, which were OK. Since my movement patterns were more old school, I really did care for that ski much. The following year I got rid of the rear entry boots, which helped a little and I replaced the T-Powers with the XRC800s. Then I found PMTS. As it turned out I was on the right ski at the right time for my ability and learning PMTS.

Last year I picked up the Supershapes, I got out to CO & HSS for an alignment session and 1/2 day lesson and that really kicked things off. This year I feel like I have made significant progress, however I feel like I still have a long way to go. I wouldn't say I have equipment issues though.

BTW, the golf analogy is a good one. I am a 1.5 index, so I know the value of putting the right clubs in the bag to match your game.

[Arkady]

Do not take my advice too seriously, I am not a gear expert.

However, I'd like to make a point for XRC 1100 (instead of 800). Up to the last year I skied straight skis, then soft beginner/intermediate skis (Dynastar Agyl Plus). Then I tested a lot of different makes and models, and finally chose 1100. I do not regret the choice. If they felt like "too much ski", it was for probably 3 or 4 first times on the snow. One can really grow fast into these skis. They are somewhat harder to turn then 800, but much more stable at speed. As an afterthought, I might have tried 1200 instead (these felt way different than 1100, stiffer and speedier, but at the time I got 1100, 1200 would likely be too much for me).

A related question for more experienced Head users, how you would compare 1100, 1200 and SuperShapes, different seasons also?

[40below]

Excellent point and request, Arkady -
because both the SuperShape & 1200 are sandwich construction,
whilst 1100 & 800 are X-frame.

Also, would it be asking too much to throw in comments on the
effects of Chip vs. non-Chip ?

[John Mason]

I skied these back to back at Holiday Valley this week as my SS needed some ptex work from the minimal snow out in Tahoe a few weeks ago.

I find them very similar except in these areas:

The SS turns tighter (duh)
The 1200 is less forgiving on fore/aft balance
The SS is a slightly more comfortable ride

Both lock up and carve great

If I'm doing cruising blues and want to go fast gs like I prefer the 1200. If I'm doing steeper stuff or just want to turn more I like the SS.
If it's crudy or spring conditions I grab the SS.

I have the I75M chip and it's a more comfortable ride than either the 1200 or SS but it is no-where near the carver of those two skis. So it basically just decorates my basement wall now.

What I would have changed? I didn't realize that lots of skis are designed to be easy for the tails to break since that type of turn is what many people want. I would have picked more of a carving ski earlier had I known what I know now. The I75m's were much improved in this tail regard by moving the binding forward from the default factory setting.

[40below]

I didn't realize that lots of skis are designed to be easy for the tails to break since that type of turn is what many people want. I would have picked more of a carving ski earlier had I known what I know now.

John - what have you felt, specifically, in the designs which give this characteristic?
and conversely, what specifically yields the desirable carving characteristics ?

Here we are, back to the story of inter-relationships -

* the relationship of the outline shape,
* to the dimensions,
* to the materials used,
* to the way in which the materials ARE used or put together to build the ski.

As I built surfboards professionally for a number of years, I could shape 2 boards with the same dimensions at 12'' from the nose / widest point located @ __ " from center / 12" from tail; but they would have different riding characteristics if I altered the overall planshape (outline) of how the curves connected those points.

Not to mention how the overall "foil" (think 'airplane or bird's wing' in cross-section) or thickness was distributed.

Thx everyone for these inputs -
it's helping to get that learning curve down to 9.8m @ --- cm (insert ski length of choice)

;>)

[John Mason]

I don't know 40below

whatever those combinations - empirically the SS is one of the best I've

I have the 1100 and 1200 sw model. They are vitually identical. But the 1200 has a layer of 'liquid metal' in it's laminate stack. Whatever the technology, the 1200 does not pass along vibration which gives the subjective feeling of staying connected to the surface better, especially when it's icy.

The SS shares the liquid metal layer technology.

I had a metron B5 which has a similar overall shape and market positioning as the SS, but they are totally different skis. The B5 is very heavy and compared to the progressive flex of the SS, very stiff. But the B5 will carve a good line. I just find the SS more versitile because it's more responsive to pressure than the B5 was.

The SS seems to me to do the crud better than the 1200 because rides more up on the crud because of its surface area. Both are pretty easy to tip because they are both narrow under the boot.

That does bring up a point. For a PMTS skier a ski that is narrow under the boot gives you more leverage for using tipping skills than a wider ski.