EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Ski Gear Discussion › Wood core vs. foam/synthetic core -- what are the pro's and con's?
New Posts  All Forums:Forum Nav:

Wood core vs. foam/synthetic core -- what are the pro's and con's? - Page 2

post #31 of 54
My $.02

The one thing that seems to have been overlooked and discussed, is the purpose of the core. From my point of view, it just opens up the gap between the topsheet and the base. This is where the real strength of your ski is created . If you want a 'real' stiff ski, build a pair of skis on a thicker core.

I work in the aerospace industry and have a little to say about this 'foam' that everyone seems to be unsure of. We use foam core in varies applications in the design and manufacturing of composite piston aircraft and personal jets. On our shop floor there are RACKS full of foam. They come in all different thicknesses and densities. There are some sheets that look like sponges (large air voids) and some so dense that they seen solid. Some have commented on the quality of these cores and that is subjective just like the wood used for the wood skis (as noted about softwood and knots). From my experience this stuff is just like working with wood. We work with it in the same way that you do wood. Cutting, milling, chamfering and drilling it is all the same. I would bet that most of the foam that is made for the composite industry for the most part is coming out of the same plants. (Higher quality standards for areo of coarse)

If you discuss foam in the terms of a injectable goo, them yes a foam core ski is junk (no control). If you talk about building a ski around a milled and 'consistent' core of foam, them I think that it would be on par with any wood cored ski. I would go so far as to say in the ski building biz, you could mill foam and wood all in the same day on the same machinery.

At the end of the day I wouldn't use the core material as my starting point for purchasing a new pair of ski with the technologies that are in place today. There are much larger parameters in my purchase decision (size, cut etc).
post #32 of 54
This thread really came around with some useful info. I learned quite a bit thanks to SJ and others regarding dynastar's milling process.

Cheers for othe updates, guys. (living in Japan, I don't have ski-shop chat or locker-room gossip regarding gear. I appreciate this site keeping me up to date.)
post #33 of 54
Quote:
Originally Posted by SierraJim View Post
There was also a different composite known as Rohacell which was introduced in the Omeglass SL ski of decades ago. This material was derived from an acylic based product and was again milled to shape.
Same as the orange BIG?
post #34 of 54
Thread Starter 
Quote:
If you discuss foam in the terms of a injectable goo, them yes a foam core ski is junk (no control). If you talk about building a ski around a milled and 'consistent' core of foam, them I think that it would be on par with any wood cored ski.
This comes down to the crux of the matter from a consumer's perspective, and illuminates why these forums are so useful in getting information out there to us buyers: that is, how is a potential ski buyer to know whether the synthetic core ski that they are perusing on a manufacturer's website is the real deal, or "injectable goo". Without someone with a bit of knowledge about who's doing a good job and who isn't, who then tells us about it on this forum, all we see are terms like Multicell and Isocell. How the heck are we to know what that means if the website doesn't explain it and convince us it's just the best hi-tech material ever invented? If we've got some healthy skepticism and raise an eyebrow (like we should -- eg. the question about Liquidmetal shows that skepticism is alive and well here), we may pass over a potentially excellent product. We'll just click to another site and see familiar, confidence inspiring materials like beechwood and poplar, layered with titanium and carbon, and "Whoa, Martha! There's my ski!". That stuff just gives you the warm and fuzzies, don't it?

Seems to me that the top-shelf manufacturers like Dynastar and Stockli should be doing a much better job of getting the word out that their product isn't crappy cheap foam, but high density, highly engineered, well-finished, durable stuff. And show us the proof, guys! Back up your claims of excellence with some evidence that it isn't injectable goo! People like us love to read something that's right out of an engineering journal. For a great example of what I'm talking about, check the tech articles at Lou's site http://www.lous.ca/techarticles.htm (scroll down to the University research ones).

At the moment, the ski press doesn't write about synthetic cores (at least I haven't seen it), and most store people don't really know, or won't give a straight answer (I wouldn't trust most of them anyway -- with apologies to Sierra Jim and Dawg; I didn't mean you guys, but you know the type of salesman I'm alluding to -- there are lots of them around Toronto, where I'm at, but that's another story).

So, Kudos to the forum for shedding some light on this. Well done.

BR,

Svend
post #35 of 54
I read somewhere that it can be difficult to make wood consistant in the manufacturing process. However, I know I have seen somebody make skis out of crate wood. I kind of like the K2 triax braid wrap over wood construct. It is light and strong.

I have been trying to beat up my pr's so I can get some new guns.... but they just keep flying. And I have a second set of touring pr's still in very good condition. Someday I will get a new set of guns just because.

So, you want bouncy skis? Or skis that are damp? Want skis that flex in pow? (soft tip and tail).

Personally, I think wood skis make good planks. Engineered plastic core (I really don't know why they call it foam) ... allows for putting stiffness under foot and allowing for a softer tip & tail. And they are lighter.

They say soft skis chatter... but I ski 185's and have never really noticed. Maybe I think chatter is normal. By the way... I will race, but not on ice.

People around me keep stocking up on the guns... great single ski for pow and groom. '07's were going for $350 used/w binding, $400 new/without. '08's will follow starting March. Binding, half price in summer.... so the price is right.

I watch a lot of Warren Miller vids... and other extreme skiing vids. I see a lot of pr's and guns.... but then again, I am paying attention. In WM - Off the Grid, this guy makes a 250 foot leap off a cliff... looked like guns. 'Course he landed on his back... in deep pow.

So, I have seen so many 'plastic' skis charging down insane Alaskan steeps... And I ski mine hard, always doing surgery on the bases... so I don't know what all the fuss is about.

I used to think Volants were cool... all that metal. But I have been hearing more about delams... I wish my skis would delam... then I would have to get new ones...
post #36 of 54
I think 'foam' cores have gotten a bad rap over time. Back 20 years ago I would say that a wood core was definatly more resilient, and stood up to much more abuse.
Circa '89.....
100 hard days on a wood core K2 KVC and it still had pop.
100 hard days on a foam Rossi 4S and it was dead.
But, I think the Elan Comprex S was a wood core and had definatly lost alot of life after 100 hard days.

It is the entire building process that makes a ski durable, the sum of it's parts and not just it's core.

Technology has changed, and impoved manufacturing methods have made foam/composite cores much more hardy than they were 20, even 10 years ago.

That being said, I'm still going for a wood core if I have the option........
post #37 of 54
cant speak for all the synthetic core skis out there, but the 2 rossi's (B2's & Saltos) I've owned have lost a lot of pop after about 30-40 days. Quite noticeably so when flexing the ski compared to the same brand new ski in the shop. It's like I was flexing 2 completely different skis. The one with 30+days felt at least 30-40% softer.
post #38 of 54
Quote:
Originally Posted by SGN View Post
Seems to me that the top-shelf manufacturers like Dynastar and Stockli should be doing a much better job of getting the word out that their product isn't crappy cheap foam, but high density, highly engineered, well-finished, durable stuff. And show us the proof, guys! Back up your claims of excellence with some evidence that it isn't injectable goo! People like us love to read something that's right out of an engineering journal. For a great example of what I'm talking about, check the tech articles at Lou's site http://www.lous.ca/techarticles.htm (scroll down to the University research ones).
The products speak for themselves. Threads like this are irrelevant because the haven't really told anyone anything about how the thing will ski. I don't care a fig how the core is built if that isn't going to be tied back to design specifications and how it skis. And so far that hasn't happened in this thread. I don't see the inherent problem with making a ski core using a reaction injection molding process, squirting goo as you called it. How do you know that RIM foams are crappy cheap foam, and not high density, highly engineered, well-finished, durable stuff? All things being equal, being cheap is in it's self a benefit if you are talking about cost effective solutions. I doubt anyone unfamiliar with either ski manufacturing or polyolefins injection molding would actually be able to show any problems that may exist with squirting goo to make a ski's core a priori.

So far ski mfgs don't even provide info regarding basic performance specifications of their products such as weight, flex, frequency resonance, etc... I would much prefer to see accurate descriptions of the flex (both longitudinal and torsional) and weight, for each size and model of ski produced than some sort of detailed white paper on composite core construction that isn't tied to performance.

Fyi, I found this blog entry that details composite ski construction and testing. It is actually pretty interesting to see how different builds performed. Link
post #39 of 54

Kingswood skis + bamboo cores

Kingswood ski - www.kingswoodskis.com (Aotearoa New Zealand) are now using bamboo for their cores.
cores: vertically laminated bamboo
Other manufacturers are now picking up this great material, but Kingswood pioneered the use of bamboo for ski cores. We chose this material because it’s strong! (20% stronger than maple) and it’s consistent. It has good pop and shock absorbing qualities. Plus, it regenerates quickly and that’s good for the planet.
post #40 of 54
Thread Starter 
Quote:
So far ski mfgs don't even provide info regarding basic performance specifications of their products such as weight, flex, frequency resonance, etc... I would much prefer to see accurate descriptions of the flex (both longitudinal and torsional) and weight, for each size and model of ski produced than some sort of detailed white paper on composite core construction that isn't tied to performance.
Tromano, you're right, but I don't see why we can't get both from the ski makers. Performance is certainly important, as are the other physical properties you mentioned -- it would be very useful information to get, esp. a flex index of some kind, as it would definitely help choose a ski based on one's body weight and skiing style. Good ski reviews, like those here on the forum and some other sources, are providing some of this info, but it shouldn't be left up to ski reviewers to provide -- the makers should do it.

However, durability is totally relevant, as it is with any expensive product purchase. Performance is very relevant too, but its a separate discussion and is mutually exclusive of the topic of durability.

Some of the forum members have clearly verified that some foam core skis start to lose performance after 30 or 40 ski days. For most of us, that's less than two seasons. Not all of us have the means to spend another $500 or more every two years just because our boards have become flacid. Some of us are students, or have four kids in hockey or dance programs (believe me, I know -- at $6K per kid per year, minimum, on one income, that adds up!). Even if we can afford it, we want good value for our money, and if the ski craps out, I'd get pissed off and feel ripped off (and I'd probably never buy that brand again). For $500 or $800, I want quality and I expect to get it. If a thread like this helps fill in the gaps that the manufacturers or press or stores aren't filling, then that's all good as far as I'm concerned.

Cheers,

Svend
post #41 of 54
Have you ever heard someone say "I'm sporting a tremendous foamie?" I don't think so.
post #42 of 54
Quote:
Originally Posted by Ruxpercnd View Post
I read somewhere that it can be difficult to make wood consistant in the manufacturing process. However, I know I have seen somebody make skis out of crate wood. I kind of like the K2 triax braid wrap over wood construct. It is light and strong.

I have been trying to beat up my pr's so I can get some new guns.... but they just keep flying. And I have a second set of touring pr's still in very good condition. Someday I will get a new set of guns just because.

So, you want bouncy skis? Or skis that are damp? Want skis that flex in pow? (soft tip and tail).

Personally, I think wood skis make good planks. Engineered plastic core (I really don't know why they call it foam) ... allows for putting stiffness under foot and allowing for a softer tip & tail. And they are lighter.

They say soft skis chatter... but I ski 185's and have never really noticed. Maybe I think chatter is normal. By the way... I will race, but not on ice.

People around me keep stocking up on the guns... great single ski for pow and groom. '07's were going for $350 used/w binding, $400 new/without. '08's will follow starting March. Binding, half price in summer.... so the price is right.

I watch a lot of Warren Miller vids... and other extreme skiing vids. I see a lot of pr's and guns.... but then again, I am paying attention. In WM - Off the Grid, this guy makes a 250 foot leap off a cliff... looked like guns. 'Course he landed on his back... in deep pow.

So, I have seen so many 'plastic' skis charging down insane Alaskan steeps... And I ski mine hard, always doing surgery on the bases... so I don't know what all the fuss is about.

I used to think Volants were cool... all that metal. But I have been hearing more about delams... I wish my skis would delam... then I would have to get new ones...
The pocket rockets in those video are pro issue wood core pocket rockets, yes they actually do exsist.
post #43 of 54
Quote:
Originally Posted by skeezer View Post
Um - you wouldn't even look at , say, a Fischer RX8 because it isn't wood ?
According to the Fischer site, the RX8 has a wood core. I've heard this before even though the site has always stated very clearly that they have wood cores.

I own RX8s and really enjoy them. I think it's interesting how hard it is to shake a bias. If I found out that Fischer had been passing on bad information and the RX8s were foam, I might like them less. Crazy.
post #44 of 54
Quote:
Originally Posted by BushwackerinPA View Post
The pocket rockets in those video are pro issue wood core pocket rockets, yes they actually do exsist.
One of the two Krist(?) brothers, that ski in Idaho in some of his movies, skis the pro version of the gun.
post #45 of 54
Quote:
Originally Posted by SGN View Post
However, durability is totally relevant, as it is with any expensive product purchase. Performance is very relevant too, but its a separate discussion and is mutually exclusive of the topic of durability.

Some of the forum members have clearly verified that some foam core skis start to lose performance after 30 or 40 ski days. For most of us, that's less than two seasons. Not all of us have the means to spend another $500 or more every two years just because our boards have become flacid. Some of us are students, or have four kids in hockey or dance programs (believe me, I know -- at $6K per kid per year, minimum, on one income, that adds up!). Even if we can afford it, we want good value for our money, and if the ski craps out, I'd get pissed off and feel ripped off (and I'd probably never buy that brand again). For $500 or $800, I want quality and I expect to get it. If a thread like this helps fill in the gaps that the manufacturers or press or stores aren't filling, then that's all good as far as I'm concerned.

Its true that there is something of a common knowledge the flex in some foam skis breaks down, sooner than expected. Therefore, I don't know who is really was fooled by the solly pocket rockets and thought they were getting a macho ski. Those skis were never burly to begin with. We aren't talking about a squad or a R-EX or a atomic race ski or a RX8 that turned into a noodle after 30 days, but a ski that was supposed to be soft. The PR was very popular as it was and is still being made in one form or another. I guess I need a reminder. There are at least 4 major ski makers who have extensive foam or composite core offerings. Exactly which skis aren't holding up?

There are plenty of wood skis that have durability issues. Every ski breaks down and goes floppy after a while, this should be expected. But there are also reports of skis with unexpected problems like blown sidewalls or delams after just a few days use, many of those are burly wood core skis. Look at this years katanas or the im88 from 06-07 with the sidewall cracks. Both skis have had durability issues but are still considered good skis.

You are talking about apriori approximation of the life span of a ski based on it's construction materials. It isn't that simple, design and implementation are important too. It seems to me that the best way to know if a ski, any ski is going to last is to wait for a year and see if it has a good track record. There are people on this forum who ski 100 days a year, which is a lot more than me. Many of them review skis and will tell you what skis are holding up and which aren't.
post #46 of 54
Quote:
Originally Posted by Matthias99 View Post
Google found this:

http://www.liquidmetal.com/technology/

http://www.liquidmetal.com/applicati...p.sporting.asp

(They explicitly reference being used in HEAD tennis rackets, so I assume this is the same stuff.)

It's an amorphous metal alloy, as far as I can tell. The claimed advantage over, say, titanium or carbon fiber stiffeners is that it won't break down as much over time from mechanical fatigue.

Head's (ski) marketing page for it:

http://www2.head.com/ski/technology....ag=liquidmetal

They also claim improved rebound. Calling it something with a "liquid molecular structure" is sort of misleading.
Head's liquid metal is a Titanium alloy, non-crystaline as described on the liquid metal pages. They are simply just a very high grade of metal sheet.
post #47 of 54
Quote:
Originally Posted by Highway Star View Post
They are simply just a very high grade of metal sheet.
They are a glass sheet, the glass just has lots of metal atoms in it.
post #48 of 54
Quote:
Originally Posted by comprex View Post
They are a glass sheet, the glass just has lots of metal atoms in it.
Don't make this more complcated for people than it needs to be!
post #49 of 54
Quote:
Originally Posted by Highway Star View Post
Don't make this more complcated for people than it needs to be!
OTOH, I'd say just calling it a "high grade metal sheet" is simplifying it to the point of uselessness if you want to really know what it is and why it might be a good thing to have in your skis (or not). :
post #50 of 54
Quote:
Originally Posted by comprex View Post
They are a glass sheet, the glass just has lots of metal atoms in it.
I think its interesting as hell. Is the metal cast and cooled quickly like glass?
post #51 of 54
Quote:
Originally Posted by Matthias99 View Post
OTOH, I'd say just calling it a "high grade metal sheet" is simplifying it to the point of uselessness if you want to really know what it is and why it might be a good thing to have in your skis (or not). :
No, it's simply just a high grade metal sheet for all intents and purposes. It really is that simple. The only thing that's special about it is that it's harder to permanently bend than other metals....part of the problem with that is that Head made the im88 too soft in the first year and the ski would break due to high shearing forces....it's much beefier now.
post #52 of 54
Quote:
Originally Posted by youngsman View Post
According to the Fischer site, the RX8 has a wood core. I've heard this before even though the site has always stated very clearly that they have wood cores.

I own RX8s and really enjoy them. I think it's interesting how hard it is to shake a bias. If I found out that Fischer had been passing on bad information and the RX8s were foam, I might like them less. Crazy.
I own RX8's too & love 'em , but no, there ain't no wood in those babies(at least on my 05/06 models) Read the writing on the tails - "Air Carbon Titanium"
http://www.fischer-ski.com/en/techno...d_group=20130#

But who cares - they're awesome, however they're made
post #53 of 54
Quote:
Originally Posted by skeezer View Post
I own RX8's too & love 'em , but no, there ain't no wood in those babies(at least on my 05/06 models) Read the writing on the tails - "Air Carbon Titanium"
www.fischer-ski.com/en/technology.php?id_group=20130#

But who cares - they're awesome, however they're made
The specifications also include the following along with a picture of a wood core along with the cap constuction. i don't think "Air Carbon Titanium" refers to the core. The race skis also have "Air Carbon Titanium" and they certainly have wood cores.

HIGHLIGHT TEC
SANDWICH CONSTRUCTION
A unique concept in ski core manufacturing that gives the entire ski construction the ultimate in stability. The Sandwich Sidewall Construction is the result of an intelligent layered structure with a wood core to give the ski edges perfect support and make them harder and more durable. Compared with other constructions the ski's shock absorbing properties have been improved considerably - just like the more even power flow to the edges.
post #54 of 54

I love my Salomon 1080 Foam core skis!  I got them used from a guy who weighed about 165.   I only weigh about 130 tops.  I've skied them over 140 days, and they still kill it!  I have other skis with wood too.  Maybe I like a more flexi ski because I'm light, but these skis carve like a demon!  I also love a stiff ski, so go figure.  I don't care that this is an old thread.  My 1080 foams kill it for me still!

 

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Ski Gear Discussion
EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Ski Gear Discussion › Wood core vs. foam/synthetic core -- what are the pro's and con's?