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April, 2025

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Sintered Ski Base Density

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Cyanicenine
Posts: 966 - Karma: 2,291
First some info on sintered bases for those who don't know: "Sintered bases are created by taking the plastic in a powder form and slowly heating it, supercompressing it into a block, which is then sliced into sheets. The different ratings you see for bases (sintered 2000, 3000, 4000, 6000) are a rating of how dense the material is, so a sintered 6000 base is more dense than a 4000, and thus there are finer pores and the base is harder. The process of creating sintered bases allows for the bonding to create a much higher molecular weight, making it stronger than extruded. When you wax a sintered board you are filling the pores with the wax, the plastic is "absorbing" the wax like a sponge. When a sintered board goes too long without being waxed you will see it start to dry out, generally along your edges you will see the base start to turn whitish." -Taken from http://easyloungin.com/forum/topic.php?id=5278

My question is specifically about base density. Some manufacturers state their ski base density up front. Others I cannot seem to find no matter how hard I look. I would really like to know how the bases differ between manufacturers as this is a huge consideration for me when I buy a ski.

The following is a list of ski manufacturers and density when I can find it, would love if someone could help me fill in the holes.

Moment - Durasurf 4001

Armada - site says s7 base is their toughest base material, but doesn't say what it is.

K2 - ???

Lib-tech - NAS description says "Ultra High Molecular Weight P.E. Speed Walls" snowboard bases are "Sintered Carbon 9991 Base Material" I know my own pipe NAS seems pretty dense but it would be nice to have a real number behind it.

Atomic - ???

Rossignol - ???

Line - Sintered Fatty Base & Edge 30% thicker (according to EVO) 30% thicker... than what it doesn't specify)

Salomon - ???

If anyone could provide info so I can fill in the holes here that would be great.


13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
Generally manufacturers will use a number of different bases. Salomon for example, use a differnt base on the pro pipe to the suspect. The same is true for armada with the pipe cleaner.

Generally if a ski is designed for pipe it will lickly have a higher density base. Skis aimed more at the jib market will usually have a less dense base, which makes it easier to maintain and cheaper.

The race skis will usually have the highest quality bases, and these are often used on the skis the pros use, but they are not generally available to buy, as they would require to much care and would cost to much.
13 years ago
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RudyGarmisch
Posts: 25444 - Karma: 13,856
ON3P uses Crown Plastic Durasurf 4001, 1.8mm thick. To my knowledge, their "standard" is 1.3mm.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
Thanks for the info, this is exactly the sort of thing I'm looking for.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
I realize manufacturers are going to use different base materials on different skis in their line up, I'm more looking for what is generally used in their high end line up. Obviously some low price point park skis won't even have a sintered base, they'll be using extruded.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
That was my point though, a high end park ski and a high end pipe ski, will probably still use differnt bases.

In an ideal world all skis would have the best most dense base, but then there would be lots of kids complaining there bases sucked because they did not care for them. It would also make prices go up alot.

Overall, any decent price ski will have a decent base, price point skis will have the worst and pipe skis will have the best.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
If your after numbers, for salomon, Pro pipe is ptex 4000 and suspect is ptex 2000. This will be fairly standard, but some brands do skimp on bases.


13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
Well the reason I made this post is because I've noticed huge variety in the way that different high end ski bases hold up to abuse as well as retain wax. You would think that if you were buying a top end ski that it would have a high density base across all brands, but this has not been my experience.

I don't understand why manufacturers do not list their base density along with all their other tech specs for their skis. This would be useful for people like me who are looking for skis with dense, burly bases, as well as people who don't have their own in home waxing/tuning setup so they can get skis that better match a low maintenance preference as you point out.

I never assumed that all skis should have top end base material for obvious reasons, but If you're already spending top dollar for top of the line skis seems like manufacturers could at least grace consumers with this kind of info before we drop a ton of cash on a expensive ski.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
This is exactly what I'm after. I know first hand some brands do indeed skimp on their bases and I'm looking specifically in pinning them down.
13 years ago
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50Kal
Posts: 2836 - Karma: 5,541
My 11/12 Armada base is pretty fast. That and deep. Found that out the hard way. I hit that rock thought that It was gonna be a good core shot. Turned out to be just a good cut to the base. A little ptex and she was solid.
13 years ago
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Heart
Posts: 6156 - Karma: 3,464
Line seems to have pretty nice sintered bases. My chronics are really fast, although they dry out quickly and I have to wax them pretty frequently.
13 years ago
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rozboon
Posts: 1642 - Karma: 868
Just gonna throw it out there but the whole base pores thing was pretty much proven to be a myth... this VERY TL;DR thesis goes into it in considerable detail: http://epubl.luth.se/1402-1757/2006/03/LTU-LIC-0603-SE.pdf
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
Great post! For whatever reason I'm finding this subject intriguing, and that PDF is a good read. Aha, the author sounds sort of pissed while disproving the mantras. +k only 12 pages in.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
That article was really long and confusing. It seemed to mostly be saying bad things about stone grinding. The ultimate conclusion, unless I'm mistaken, was that waxing works, but not due to the conventional idea of pores, but due to the smoothing out of the p-tex fibers.
13 years ago
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cubber
Posts: 1933 - Karma: 638
Which makes more sense than wax "evaporating" from pores, as our shop tech says (paraphrased). This is a very educational thread, I award gold stars to everyone. Also, threads for pdf when not on mobile
13 years ago
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grown-ninja
Posts: 3031 - Karma: 175
just some nonsense input,  moment has the best bases ive ever been on, going on my 5th season with my moments and their bombproof, granted im not a park rate and was out 1 season due to a injury and last season there was no snow...haha but other than that great bases.
13 years ago
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ballsofsteeze
Posts: 611 - Karma: 45
So I get that higher quality bases, like the 4000, will need more wax more often than, say, 2000s. how much more are we talking here? i never waxed my skis regularly, but i just got on3ps with the 4001 bases. how often am i going to need to wax these puppies to keep them fast?
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
^ it will depend on a few things.

How often you ski, snow conditions, if your hitting alot of rails.

I generally wax my skis 1-2 times a week. If you do it this regually they will get super fast and stay in great condition.

If you only ski 1-2 times a week you could wax less, but a high quality base deserves looking after and will reward you for looking after it.

Regular stone grinds which are suitable for the conditions will also help alot, but will obviously shorten the overall life of the base. But if they are a park ski, its unlikely you will wear them out by grinding, before they break down through rail abuse.
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
From their research, it also seems that a ski base that has not been stone ground and finished with a steel scraper instead, and hasn't been waxed at all was the most hydrophobic. The more hydrophobic or water resistant a base is, the better it will slide. Interesting stuff......

Also found this passage very interesting, and once again, the author sounds pissed and I like it :D

"It seems that at the end of the 1970's the X-C community missed the opportunity to reconsider the value of glide waxing. Traditions and inertia resulted in the community retaining their old waxing principles, which were intended for wooden skis. However, we believe that the development of new skis bases made of UHMWPE with hard hydrophobic additives (e.g. fluroplastics) and the development of a bristle free alternative to stone grinding is the most promising way to improve ski glide."

Still not done reading the article, but I'm hooked, and plan on finishing it within the next few nights. Alot of food for though in there.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
stone grinding will make a huge difference in terms of speed no matter what kind of base or wax is used.

If a base is perfectly flat, it will cause suction when the top layer of snow is melted by the fiction of the base. The stone grind gives the base a structure which helps break up this suction.

You use different structures for different snow conditions. However the stone grind will not effect how much wax a base will absorb in any way.
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
Did you read anything from that PDF that Rozboon posted in regards to base material, waxing, and finishing? It's all based on cross country skiing, but in terms of base materials and finishing techniques it's directly transferable to downhill skiing.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
^ no I have not read it yet, Im talking from my personal testing.

My previous shop had a wintersteiger base grinder and I had the chance to test out, different grind methods and wax techniques.

I used different base grinds on the same type of ski with the same base and same wax. I also tried no structure, different wax techniques and overall the most significant improvident to speed was using the correct base grind in conjunction with a suitable wax for the conditions.

A solid structure will help allot in terms of gliding.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
also just to add, if that PDF is in reference to XC skis, there are some big differences when it comes to downhill skis.

XC skis are much narrower so less friction would be caused meaning less melted snow so less suction. The speeds are also generally much slower so again less friction so less suction.

Im sure some of the info translates, but trust me, if it was faster to not grind or wax skis do you not think all the race teams would have adopted that technique years ago.
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
Yeah, the article really focuses on factors affecting ski glide, most of it in regards to base finishing, base material, base treatment, and base contamination. Since X-C skis often use the same materials as downhill stuff, it all really applies. They did sort of neglect base shape, and ski shape though, both affecting ski glide.....

The big reason that article is against grinding and waxing without any regards to the actual base shape, is that a waxed and ground base first of all become contaminated much more easily than a base that has been hand finished with a scraper and hasn't been waxed. Grinding and waxing also reduce the hydrophobic properties of a ski base according to that article, and basically the more hydrophobic a base is (repels water) the better it will glide. When you grind a UHMWPE base it also takes away some of the hydrophobic properties of the base, reducing glide even more.

And when ask if these were all true, then why aren't we following what this article has to say, they sort of answer that by talking about the history of X-C, when in 1970 we switched from wood skis to plastic skis. Basically pre-1970 wood skis were given a huge advantage when treated with a form of wax, it largely increased the wooden bases' hyrdophobicity. During that switch-over, really, tradition carried on and old habits were transferred over to something completely different than the old wooden bases and no one questioned the habit.

It's all really scientific stuff, but it's all backed by legitimate study, but I wouldn't sweat it too much. Because skis come from the factory nowadays with a storage wax and a base grind, you really have to stick with waxing skis, once you've waxed and base ground, there is no turning back. And really if you aren't a pro-racer, looking to beat out Bode during the next downhill race, I wouldn't read in to the article loads either, in reality, all of the fancy words, thoughts, ideas and studies, aren't going to make your weekend on the slopes considerably better because you got down the mountain slightly quicker.

Glad this has become a nice legit thread though :D

13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
^yeah sounds like it may be quite interesting but as you say, not really relevant to downhill skis.

XC skis dont generally come stone ground so you have more options, but I doubt you will find a downhill ski which has not be ground and waxed from the factory.

You say most skiers wont be interested in getting the right base grind but certainly getting the right setup for the base is very important. Have you ever skied on a really cold day, where you barley move. Well get the right grind and a good cold wax, you will get much more speed.

A great base is also very useful in the park. If your skis are well maintained you can get up to speed allot easier, this means you can take shorter run ups, get back up to speed after mistakes and generally shred the park harder with less effort. Most pro athletes will have there skis ground and re-waxed every day during a comp.

If you have never had a stone grind, go get one for the conditions and you will be amazed what a difference it makes.
13 years ago
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Session
Posts: 5408 - Karma: 22,541
Base structure that suits your snow type is just as important as a good wax.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
From what I understood of the article waxing did indeed help with glide initially. The problem was that this advantaged quickly disappeared versus the unwaxed unground ski over time due to the waxed ski accumulating dirt more easily.

I'm still a bit disappointed that it doesn't look like I'm going to accumulate a substantial amount of hard numbers for base density. All I know is anecdotally I have skis that can slide right over boulders and have little or no damage to show for it, and I have other skis that seem to gain huge scratches and dents out of no where, just skiing on well covered groomers. Base density makes a huge difference here, unfortunately it's hard to find any concrete numbers, you just have to buy and try.
13 years ago
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onenerdykid
Posts: 6744 - Karma: 11,760
Concerning base structure, I will tell you that our WC race department puts a ton of detail in creating the right pattern for the condition of the day. Same for wax selection, and base prep in general.
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
A sidenote with regards to waxing: Waxing is also very beneficial to a skis edge and any small nicks, bumps grooves, even those on an extremely minimal level will be filled with wax, and this helps inhibit water, which eventually leads to rust and edge deterioration. Anyone here wax their sidewalls occasionally? Really, it is part of the skis running surface.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
waxing will have no real effect on edges.

What you are better doing to maintain your edge is keep on top of any burs, by filing them down reguallgy. What can work very well is having the edge sharpened, this gets rid of any burs, which could catch and lead to more damage. Then you would want to round the edge again underfoot, if your hitting alot of rails.

The worst thing you can do is just leave an edge. It it gets cracked and uneven its much more lickly that a small impact will pull the edge out.

And as for waxing sidewalls, that will not help at all.
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
Yeah edge maintenance is huge. So many people just don't do much edge maintenance and it just destroys edges...

The sidewall thing though, weird habit of mine maybe? Whenever I have any drips along the sidewall, I smooth them out real quick after with the iron by setting the ski on it's side then scrape after. Forsure though, when you set a ski on edge at a pretty aggressive angle the base will contact the snow and it essentially becomes a running surface. I know the race guys are pretty horny about sidewall planing, partially for this reason, moreso to reach the edge with a file. A big name company also made a ski awhile ago with the intention that you wax the sidewalls for this reason, I can't seem to find it. +K to anyone who comes through with that.
13 years ago
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tomPietrowski
Posts: 7290 - Karma: 18,697
Im guessing you mean the volkl race skis with the "spped Wall"

Waxing sidewalls really though will have little to no effect as they are made of ABS plastic, not ptex.
13 years ago
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NinetyFour
Posts: 8650 - Karma: 13,410
Ahaha yeahh! That's them! Yeah, although if the wax did increase the hyrdophobicity of the sidewall, then that would translate to a better gliding surface. Those skis with the speedwall do have ptex sidewalls. I just love that idea :D +K
13 years ago
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razors-chaz
Posts: 2255 - Karma: 1,250
had a read through of this thread and its solid and really interesting for somebody who is interested alot in ski tech. Im looking at buying new park skis this coming season and looking at all the different options and tech pros and cons. Can somebody answer my question of K2 skis have what they call swapbase is this a sintered, extruded or some other kind of base material?
13 years ago
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KillaSteeze
Posts: 3329 - Karma: 351
pretty sure its this guy i saw talking alot about k2 bases in another thread, heres his profile

https://www.newschoolers.com/ns/members/profile/member_id/5904/

pretty sure he works at the K2 factory making their skis ao he will probaly be able to answer your questions
13 years ago
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a_pla5tic_bag
Posts: 9243 - Karma: 5,677
i think the swap base is the graphic. i think. If not i'm pretty sure domais are extruded, and recoils are sintered last i heard.
13 years ago
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razors-chaz
Posts: 2255 - Karma: 1,250
thanks ive pm'd him i will post the reply for general interest. im pretty sure its not just the graphic as the whole k2 line has this swapbase. it amazes me how little some companies put up about the tech they're putting into their skis. afterall its the tech and shape which defines how a ski is going to ride and hold up. salmon are the worst since ive started looking, basically selling their skis on a pretty picture of only the top sheet a small buzz word marketing blurb and a size list. i would be able to reel off the spec, tech, flex and sizes of skis going into a shop and acctually handling them but im looking to get this seasons (they are for my birthday afterall) and so cant really do that.
13 years ago
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rozboon
Posts: 1642 - Karma: 868

While it would be nice if ski manufacturers included this info, you have to remember that what you've said about Salomon basically covers off what maybe 85% of skiers buy their gear based on.

Does it look cool? Check.

Does it have MOD MONIC TI HARMONIC BAMBOO KERS BOOST DECK? Check.

= buy.

13 years ago
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RudyGarmisch
Posts: 25444 - Karma: 13,856
Your purchase drives change in the industry, buy brands that value your values.
13 years ago
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Piste.Off
Posts: 11586 - Karma: 1,860
Nothing gets me going more than hearing a woman discuss the chemistry behind sintered ski bases. Mmhmmmm
13 years ago
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rozboon
Posts: 1642 - Karma: 868
Believe me, if shipping wasn't $64 million to our little backwater I'd probably have been all over a pair of ON3Ps a long time ago.

That said, my #1 priority is supporting my local, so if that means buying a big brand because that's what they stock then that's the way I'm going in the first instance.
13 years ago
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razors-chaz
Posts: 2255 - Karma: 1,250
Found out the swap base is a clever piece of design by k2 to massively reduce base material wastage. They basically die cut the first design for one ski then use the cut out matial to make the same design but coulour swapped base for the other ski. I do realise that lots of people get sold skis on little more than the top sheet and what a sales rep would say to you about them but plenty of the other large brand companies tell you alot more about their skis, in short im not going to buy a ski i know little about.
13 years ago
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razors-chaz
Posts: 2255 - Karma: 1,250
my bad its not the normal wastage of one ski used on the other but the wastage of one pair is used in a swap of colours in the base for the next pair on the production line
13 years ago
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Twig
Posts: 6455 - Karma: 61,810
yeh, line do that too, thus all the different colour schemes on the bases.
13 years ago
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razors-chaz
Posts: 2255 - Karma: 1,250
entirely unsurprising with line being owned and made by k2. funny that line dont really shout about it like k2 do but it is a bit weird that they say "swap base" but dont have anything explaining what it acctually is
13 years ago
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Twig
Posts: 6455 - Karma: 61,810
yeh, line at least have been doing it for a good while and i presume k2 have too. I guess its just that now, with being 'green' becoming more fashionable, k2 have made more of a fuss about it.
13 years ago
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rozboon
Posts: 1642 - Karma: 868
Ahhh. Makes sense. I always wondered why half the K2s you see in ski films have different bases... I always just figured it was some sort of pro-model prototype special.
13 years ago
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razors-chaz
Posts: 2255 - Karma: 1,250
I also found out the materials used in the k2 park skis. The Iron Maiden Recoil and the 50th Anniversary Recoil use Sintered PTex base, but the Sight, DOMAIN, and Press all use extruded PTex. if anybody is interested. i dont see why it doesnt say this on their site. they go to the effort of telling you its a swap base they might aswell say this has a sintered swap base or and extruded swap base. it would have made my hunt for skis alot quicker
13 years ago
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Twig
Posts: 6455 - Karma: 61,810
being cynical for a second here, but the majority of people who buy skis will never have heard of sintered/extruded bases or the different types of base within those categories. If a company then says "we use an extruded base" at least some of these people may then look it up and find out its a cheaper, slower base.
Even fewer people will know about the difference in grades of Sintered bases but the same logic applies. If the big companies advertised they only use sintered 2000 but boutique brands use 4000 then people will take notice. Omitting the information is probably better for sales in the majority of cases.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
Didn't realize this thread was still going. Thanks for reporting back on the k2 skis, I had been wondering about swap base as well. It seems really odd that K2 would not say if it was an extruded base or not, I understand (sort of) why base density is not listed. Like someone else mentioned it's simply not something most people look for and has the potential to hurt sales rather than help them if they did list it. Stating whether or not a base is extruded or sintered seems pretty mandatory in my opninion, considering there is very different maintenance required with different bases. Extruded is not necessarily worse than sintered in that it does at least have the benefit of not requiring wax, which will appeal to a lot of people who don't do their own ski upkeep.

Seems like in general if the base density is listed at all it's because manufacturers like moment and others are proud of the fact that they use a high quality base in all of their skis and are happy to list it. It does make those of us in the know, less likely to want to buy major manufactured skis with say nothing blurbs and little technical info, but we're in the minority. Still seems like it wouldn't take much to bury the info in their websites so that the average consumer wouldn't find it but those who wanted the info could hunt it down.
13 years ago
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Cyanicenine
Posts: 966 - Karma: 2,291
Apparently Icelantic uses durasurf 4001, nice to see another company listing their base construction. http://icelanticboards.com/skis/info/construction/
13 years ago
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