rockered skis

[plywood]

when mattym mentioned the K2 hellbents in the "just an observation...(ski lenght)"-thread, i thought maybe it would be a good idea to open a new topic for this theme.
well, i found some posts where some of you discussed about new ski shapes, inverse sidecut and camber....but all these posts are quite "old".

and now that this theme got actual again (at least for me ) i wanted to know if there are any news.
what happened with all your plans of new skidesigns (someone mentioned building skis like the burton fish snowboard etc.) ?

so first of all i`m posting mattym`s link again about pep fujas and rockered park riding: http://www.filmtheidea.com/fujaspage.html

then i found the patent application of shane mc conkey and others in 2002 (i think for the spatulas?)

http://appft1.uspto.gov/netacgi/nph-Par ... OFF&p=1&u=
%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=50&f=G&l=50&co1=AND&d=PG01&s1=
ski&s2=camber&OS=ski+AND+camber&RS=ski+AND+camber
(you have to copy-paste the whole 3 lines and put them behind each other to get to the patent text. to make this posts easier to read i had to split up this url)

there you can read also some interesting things about ski design for powder. they have a narrower tip to better slide through the snow for example. among other things they mention also, that powder acts more like water. similar thoughts that i had with my skis. that`s why i created a relatively long and narrow swallowtail. on surfboard this is called to increase the stability of a board....
so i`m thinking any further about the ideal skis for powder and hard crust. how should a powder ski be shaped to work in powder and hardpack? what do you think?
is there really a need for an inverse sidecut? how can we prevent stability and control in hard conditions?

and for the park revolution:
how are the hellbents? do they have a similar sidecut as the pontoons? or how are they built up? all in all it seems that with rockered skis you "loose" edge control - why not building a concave base like there were some skis some years ago? or something like the bataleon snowboards, which use the so called tripple base technology what means that in the tip and tail section they use a concave base, but the middlesection is flat. everything with normal camber...

so i`m looking forward to your feedback and hope that you won`t say "oooh, not again, we discussed all these issues years ago!"

[mattym]

I was hoping this would happen sooner or later, was ready to start it myself - glad you took the initiative plywood! Im stoked for a fully updated convo on this matter because it is basically what got me into the idea of building my own skis- and when i start building, this is basically all i will be experimenting with. I would also love to hear from anyone who has played around with reverse camber and rockering skis, and especially if anyone has tried a 5 dimension ski like the Armada ARG (go to www.armadaskis.com and have a look if you have not seen it).

Just quickly, the kind of skiing im into is pretty much backcountry jibbing kinda - like smooth flowing pow lines (trees, open whatever) with lots of natural hits u can spin, butter, whatever off. I also like skiing park too, which is where I spend my spring in the northern hemisphere season and basically where I spend the entire season back home in Aus haha (for lack of much pow). SO... I have had the pleasure this season of skiing on the K2 pontoons, we have a pair of 189s here at our shop in Fernie, which basically end up staying at my place when we have snow. If you have not seen the pontoon - check it out! The first day I took this ski out, the very first run I got was down through this tree run i love and no one skis - so there i was with 2ft of fresh and a pair of 189 pontoons!!!!!! Needless to say it was epic and the first day I spent on the toons sold me on the idea of rockered skis full stop. They exceeded all my expectations by so much I came into work the next day ready to order a pair. This was the day our K2 rep came in and explained next years skis - the 07/08 hellbent and seth - and so I decided to give the toons a miss- i will just ride our pair from work for this season. Before i continue, this is a review i wrote on the toons for newschoolers - it was pretty much straight after i rode them so i was so stoked i think i repeat myself a few times but yeh - i dont wanna use up more space with a review - i get carried away as ull see.

http://www.newschoolers.com/web/content ... ad/id/319/

So the toons only shortcoming was that it wasnt the perfect hardpack ski. I think it still works fine - for me i could have so much fun on the pontoons with only 5 cm. I could butter them, i can now spin them, and they are without doubt the most fun pow ski ive ever skied. I guess it kind of depends on how you ski- but for me - these were where its at. The K2 Hellbent for next season is the Made'n AK/AK Enemy with fully rockered tips and tails. The dimensions are 150-122-141 (or maybe 147 i think 141) and I believe they will be full sandwich/sidewall construction. Our K2 rep said they were designed to drop 80ft cliffs to switch. The seth takes a slightly different stance, there is still camber underfoot but like the 4frnt EHP there is an early rise in the tip - in effect giving it like a mini rocker.

So here is where im at with it now. I think the perfect pow ski for me is going to be like a combination of the hellbent, the seth, and the ARG. Its funny cause I had the idea and was discussing it with people and everything, and then I saw Lines skis for next year and the Eric Pollard (my fav. skier for sure) pro model has basically taken this approach, as has Salomon for their pow ski next year. Heads up - next season a hell of a lot of the manufacturers are doing something with a rocker/early rise/reverse camber. Here is a link to huge thread on newschoolers on next years skis for those interested:
http://www.newschoolers.com/web/forums/ ... 68/page/1/

But anyway, here's what I was thinking:

A ski with dimensions like so 150-123-150, possibly 140-150-123-150-140. This is because I like fat skis with nice sidecut, it makes for a snowboard/surfy kinda feel but on skis - and I want a perfectly symmetrical ski because I like skiing switch a lot too. So under foot there would be say 2mm of camber, for a running length of somewhere around 120-130cm, then an equal early rise in the tip and tail, to a point somewhere between the seth and the pontoon, and then an equal tip/tail height too. I want to make it with a bamboo core - maybe with something else to soften it a little more, possibly honeycomb in tips and tails, abs sidewalls, and then I'm not 100% on composites yet. I think for me, this would be the ideal ski for any day where I would ski at least some soft snow.

Sorry this is dragging on, im sure ill post even more soon enough, but its such a revolution to me, where skiing can head with skis like this. In terms of park skiing - andy mahre and pep rode the hellbents at x-games - proof enough they rock. These guys are where its at in the newschool revolution and they may not be spinning the most or whatever (although im sure they could) they are doing the stuff that looks super cool and is fun for them. Please check out that filmtheidea site everyone!!! Basically rockered skis = easy butters, nose and tail presses without straight legs, no catching of tips/tails if spinning on rails or boxes or if you just want to bail etc. - the list goes on! I am yet to really ski them in the park but i played around buttering, spinning off natural stuff, and sliding easier boxes and rails (this was on the toons!) and it was so fun!!!

Anyway, this will prob be a massive post I know, but I really wanna spark some conversation on this topic!!!

[plywood]

huh, quite a long post. that rocks, dude!
i just had to change the url for the patent application in my first post because she was too long, so it would have been a pain in the ass to read further posts.

so you say the hellbents have a "normal" sidecut but are just rockered? i had about the same idea yesterday.

i think inverse sidecut is not the way to go: the disadvantages of it are too big. i`m thinking of less control on hardpack, less edge control etc. but maybe here someone who rode an inverse sidecut ski could tell us more.

i like your idea of doing a relatively long middle section with normal camber. that`s more or less what i thought about yesterday when i couldn`t sleep
this middlesection also should have normal sidecut. but then my ideas differ from yours.
i don`t know if it`s a good idea to build a perfectly symmetric ski for powder jibbing. if you do so, you also had to put the bindings really in the middle, otherways the whole symmetrical thing would make no sence. and if you put the bindings in the middle i seriously doubt if they would ride well in powder because of the huge surface in the back - i suppose you had to horrible lean back...
so here`s what i would do:
let`s say we have an 120cm long middlesection on a 180cm long ski. so there are on each side 30cm left. on my skis i built a 15cm long tip. so there would be left about 15cm to rocker. so if you would put such a ski on flat ground and step to the middle, the camber in the middlesection would lay flat on the ground and the rockered tip&tail would point a bit higher off the ground. so the 30cm in the front and back would never touch the snow on hardpack. this leads to following thoughts:
we have a middlesection which is responsible for the riding abilities of a skis on harder conditions, and we got a tip and tail section which could be designed specific for powder riding.
in this tip and tail section there is no need for sidecut because of the effect i tried to describe above: this area never touches snow when riding on slopes. so i would make them straight. this prevents a wide area in tip and tail which allows you to float on powder.
for the timensions: wide skis are great. but i don`t think it`s wise to have 150-123-150 in the middle section. this would creat a relatively narrow radius. either you make the 150 narrower or the 123 wider. so i woudl do something about 146-146-125-140-140 or if you think a symmetric ski is the way to do it -146-146.
but for me (i prefer to ride "straight" lines without any tricks - i`m not able to do tricks, physically stupid ) i`d prefer to have a narrower tail section to sink into the powder. or a swallowtail. as you can also read on the patent text of shane mc conkey it`s better to have a narrower tail. it makes sliding through powder easier.

i wouldn`t take bamboo for the core.for the first attempts ash lasts fully. let me tell you what i had to experience: if you make a woodcore, the weight is nearly set. take ash for a solid core and forget honeycomb, foam and such things. they just weaken your construction and the weight reduction is barely recognizable.

maybe soon some drawings of my ideas about the perfect skis will follow, i had a bunch of ideas yesterday!
but we mustn`t forget that mattym and i we got a different riding style - but we both came to nearly identical solutions (ecept the tails)

[NEngineer]

I've never riddin a ski/snowboard with reverse sidecut and don't like the fact that they are squirly on hardpack. Also, I'm not convinced that you cannot get the same effect with a regular sidcut ski.
Also, I've heard that with a reverse camber it's hard to land jumps. Any experience with this guys?

Here's the ski that I want to make (once I have everything up and running)
Reverse camber in the front half of the ski and regular camber in the tail.
The tail is relatively stiffer than the front of the ski
The tip are a whole lot wider than the tails. Maybe even a swallow tail.
Also, the nose radius is huge. Basically the effective edge of the ski would be 140. Total length 170. the rest is all nose.
If everything goes according to plan, you could probably mount the bindings center or even slightly forward of center of the effective edge. Also, you won't need to lean back. The tips should stay up no matter what.

[mpm32]

If the powder acts like water, I wonder how skis modeled after waterskis would work. Waterskis have a narrow tip, wide waist, concave bottom (tunnel) and narrow squared off tail.

If I ever skiied on powder (I'm in the NE) or if I was even set up to press skis, I'd try something like this.

[hafte]

MPM32 here is a movie of the red Octobers from this site. http://www.skibuilders.com/gallery/movi ... bers02.asf It doesn’t have all of the features of a water ski you mention, but it looks like it skis very well. I have been planning something like this since I saw this video. My friend Korki has a Ski(?) called a snow snake that is built as you describe the water ski. It has lots of rocker and a squared off narrow tail. It has one alpine binding on the front and a strap to kick the back foot into while you ride. It is a mono type ski so he looks like a slalom water skier. Really a very strange ride. It only works in certain snow conditions. Mostly powder. Its really strang to see him ride. He has to rock back and forth to make the transition from one edge to the other.

I have started a form for a ski just like Plywood talks about. I have the form set with a 135 cm cambered center and long shallow tip 2.5 m radius. I think I can get ~53 cm long tip and my regular tail flip of 32 cm radius. I started this for a snowboard project I have in mind, but it will work nicely for a pair of skis too. I will be glassing the deck parts in the next day or so (it’s snowing again and I may not get much done if it keeps up). I’m not much of a jibber& bonker but the idea for me was to make a ski that would ride well in the powder snow we get here, but it needed a bit of camber so it will have bite on some of the traverses that we do to get to the goodies. I figured the long tip would just float off the snow and stay out of the way while the cambered center would hold and carve on the packed runs. I’m not too worried about symmetry for my purposes. The narrower tail will aid in keeping the tips up. Here is a picture from snow cad for my ski the fatbelly.

http://home.comcast.net/~mhafte/images/fatbelly.JPG

The reverse camber to me would make the ski too specific for powder only days. I was looking for a compromise that would allow for a broader all around ski.

Hey that works much better. Thanks Robogeek

AARRGGG The picture is too big!! I'll leave the link and fix the picture when I get home, so you don't have to scroll back and forth to read the thread..

Hafte

[RoboGeek]

just use BB code - its much easier

Code: Select all

[img]filename.jpg[/img]

[kelvin]

We've made a few reverse sidecut skis, (Red Oktobers, Doinks, Upper crusts) with a little bit of rocker (~2-3mm). They do perform well in soft snow and has the turn quickness of a much shorter ski. In harder conditions, they are manageable, but are quite squirrelly. The turns are a much more sliding/ drifting turn than a carved turn. That may be why they are nice in the park since you can slide, turn them really quick. Maybe someone should make rockered ballet skis.

I tried to increase the versatility of these skis by reducing the reverse sidecut and creating a tapered pintail type ski (Dr. Strangeloves). It's hard to tell from the picture on the website, due to the angle, but the widest part of the ski is about 10 cm from the tip and it tapers all the way to the tail. There is maybe 1mm of inverse sidecut. These skis worked really well, and I was using them as my everyday ski for a while. They were still easy to turn, great in powder, but was much more controllable on the hardpack. The only time they suffered was in real hard conditions, even refrozen corduroy wasn't a problem, but any ski this width would probably have problems. I did notice that they have a tendency to wash out on the bottom 1/4 of a turn, parallel or tele. I think as you get to the bottom of a turn, you start loading up the tails a bit more, and since there isn't much tail on these skis, you start to skid. You have to be a bit careful and can't really carve trenches like a GS ski. I would like to try to make these again, but with regular sidecut, like Hafte's picture.

I don't do much park skiing, but landing jumps wasn't a big problem. The biggest issue is that a lot of jump landings are fairly hard, and the squirrelly nature of these skis on hard snow may be why it's harder to land.

-kelvin

[collin]

If the powder acts like water, I wonder how skis modeled after waterskis would work. Waterskis have a narrow tip, wide waist, concave bottom (tunnel) and narrow squared off tail.

If I ever skiied on powder (I'm in the NE) or if I was even set up to press skis, I'd try something like this.

I could be wrong, but I think that before McConkey designed the Spatulas he did try skiing on water skis. On snow.

[Charlie]

If the powder acts like water, I wonder how skis modeled after waterskis would work. Waterskis have a narrow tip, wide waist, concave bottom (tunnel) and narrow squared off tail.

If I ever skiied on powder (I'm in the NE) or if I was even set up to press skis, I'd try something like this.

I could be wrong, but I think that before McConkey designed the Spatulas he did try skiing on water skis. On snow.

yes, he did, but it was after he designed Spatulas. Everybody kept saying him "hey, dude, those look like some waterskis!" And he was like "yeah, exactly, that's where the idea came from..." Than he took some Goode waterskis, put ski bindings on them and skied some sick AK line... Watch the segment in the movie "There is something about McConkey". Or maybe one of the Ski movie series...not sure...
He is THE most influential ski designer (and skier of course ) EVER...at least in big mountain skiing...

[plywood]

as far as i know davide made some skis similar as mpm32 described it. i didn`t found his post now, but it were huge skis with inverse sidecut, 160mm underfoot or something like this. davide told me that he did ski them also in the reverse direction that he usually planned to. but he sure could tell you more about how they handled.

the picture of haftes fatbelly remembered me a bit of the zag skis. the zags also have a long tip, not so long as yours, but also around 30cm. www.zagski.com

i think the point is to use camber. camber gives the ski an internal tension.
on hard ground it makes sure that the edges bite. the camber distributes the forces in a ski. some of you are engineers, so maybe you understand what i`m painfully trying to explain so if you would step on a flat ski, the distribution of the forces would be totally different than on a ski with camber. the flat ski would sag a lot more than the one with camber. so the result of a cambered ski are higher forces in tip and tail. these higher forces also affect the edges. you become a longer section of the edges which is under tension and which grips.
the thing i try to explain is following: if you make some camber the ski gets a internal tension like a bow. this internal tension increases the "resistance" of a ski to sag. and this resistance is needed to get a snappy edgehold.

this resistance also helps in powder i suppose. while on hardpack you got all the forces on the edges (longitudinal AND torsional!), in powder all the forces affect on the whole surface of the ski. these forces are higher than the ones that just affect the edges. so even a ski with camber gets bent upwards in powder.
in comparison to it, a ski with negative camber would get bent up even more. but on a ski with normal camber this effect would create again internal tension - and in my opinion this gets you a nippy ski for powder, because you can use this internal tension and resistance.
i`ve never ridden a ski with negative camber, but after my guessings here it would indeed float well, but the ski wouldn`t be as energetic as a normal one.

i`m also sure that the better floating attributes of an inverse sidecut/negative camber ski can be reached differently. the tip is the solution to everything - if it`s wide and high enough it will float. and the rockered section is just kind of an extension of the tips. so on such skis the tips help you flood and the section with normal camber gives you a snappy edge and an energetic ski.
so on hard snow they`re sure not as squirrelly as inverse sidecut/negative camber skis, but because of the shorter running lenght the can not be as stable as normal skis in the same lenght. if the advantage of rockered skis in powder compared to normal shaped fat skis is recognizable...i don`t know! maybe they are easier to slide because of the lower internal resistance....?

[mpm32]

Very cool. My warm weather sport is slalom waterskiing. I wish we had the big powder to try something like that out here.

These days we're lucky to have even man-made snow in the North East.

[mattym]

Ok, so first things first. Yeh, the hellbents have regular sidecut and are fully rockered. I agree, I'm not a fan of inverse sidecut, I do like continuous tapaering of the sidecut down to the tail (like the pontoon) though - I guess this is just beacuse u lose that jibby snowboard kind of feel that you get from a regular sidecut. I have been speaking to pep a little on this new prophecy that is rockered skis - and he was saying much the same, the jibby snowboard kind of feeling is gained from a reasonably deep regular sidecut, and then the rocker gives the flotation in the deeper snow and a seriously playful feeling in the park. His riding style is so sick, and the way he skis on rockered skis is so ahead of its time - he is a real innovator and seriously awesome skier - def a serious favourite of mine (check this edit out that he and andy mahre did on rockered skis with no poles, its the sickest, http://www.filmtheidea.com/mattpage.html - sickest skiing edit out)!!! I am going to discuss further with pep too this idea of camber under foot and a rise in the tips and tails, and see how he thinks it would compare to the hellbent (the k2 dudes are the only ones who have gotten to ride them thus far i would assume). So I don't think i mentioned this in my first post but check this out - its a vid of the new salomon ski which is pretty much of the shape we are discussing - camber underfoot and then the rocker/early rise.

http://skieur.com/index.php?module=skie ... icle&ido=7

I'm still not convinced that a symmetrical ski would not be the way to go, i think the rockered tips and tails would compensate for the lack of tail. Perhaps a little narrower tail would be good and then moun 2-3cm back from the center of the ski, but remember I am looking for a ski that will perform virtually the same backwards as forwards. I guess you wouldn't lose much in terms of skiing switch by narrowing the tail just a little, and you would prob gain more than u lose. Plywood, I like your thinking behind the length of tip combined with the amount of rocker. I like the idea of a small flat section that would then rise when you stand on the ski, and then the later half of the 30cm towards the tips and tails starts to rocker more - this is kinda what I was thinking with the early rise idea as opposed to full rocker. And I think you may be right about my dimensions too, I might just extend that radius out a little - I quite like the idea of an eliptical sidecut - something similar to the line elizabeths, but not sure if it would work on a rockered ski - any ideas on that!?!?!?!?

So the idea of playing around with honeycomb is out now, haha it was kinda a passing thought and you just confirmed my position on that. I was thinking I'd just make a shorter ski anyway to reduce swingweight, like i think id make around a 180-183, because with the rocker floatation is nowhere near as much of an issue - no need for a crazy long ski unless you are straightlining and stuff - this may suit some of you better i guess. However, i dont understand your opposition to bamboo core, i think it would be sick - super strong and nice and poppy?! Kingswood seems to kill it with the bamboo core!
I think the fact that we came up with such a similar ski probably suggests that this kind of ski shape is where we need to be looking to for the ideal versatile pow ski. I think camber is the key, but only underfoot, i think anyone who believes a regular camber ski skis as well in softer snow as a rockered ski is dillusional and not willing to accept the facts. I can't wait to get on a pair of hellbents, or hopefully my own ski if it gets made, so that i can give rockered park riding even more of a crack.

[mattym]

I also forgot to add that people often find problems with speed on skis without positive camber on harder snow. When i skiied the toons, there was a hell of a lot of snow around, but towards the end of the day there were areas of harderpack on cat tracks and what not, and they are a little slow but not stupidly slow. My idea to combat this was to use a golfball dimpled base (the StrucTurn base that is used on a lot of snowboards now). I posted a thread in the materials section about this kind of base, so if you have any ideas regarding it, check out that post.

[plywood]

the hellbents have regular sidecut and are fully rockered.

fully rockered.... what do you mean with this? maybe we had to definate "fully rockered" a bit more precise.
short and flat middlesection (about 50cm) and then rising tip/tails, right?

also interesting to see the vid about the new salomon skis. they look a bit sketchy... seems like they had a hughe amount of rocker/inverse camber. i don`t like the look of such "bananas"...

the video of pep speaks for itself - really astonishing. even i`m not talented in park riding, after this video i HAVE to build such skis
so my plans are growing.