 Poster: A snowHead
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| valais2 wrote: |
@under a new name, ...yep, if the force needed to pull the skis together is so low, if can’t see how this contributes to the idea of ‘pop’ at the end of a turn - the amount of force needed to launch me nicely into the air is not going to come from that...it’s far more likely to come from holding the edge at an angle to my direction of travel at the end of the turn - keeping the edge in - and then me deliberately forcing my body up off that solid platform .... I think a lot of things may have been attributed to camber which derive from very different elements of the complex physics of skiing.
Interesting analogy with sag in mtb and DH suspension - regret a specialist subject of mine, since I was involved in full suss mtbs since day 1 - Thinking it through the principle function of sag is to place the unsprung mass in around 30% of the travel so that the wheel can move DOWN into holes as well as UP over bumps. The whole point is keeping the contact point consistently in contact with the ground. I am thinking through the analogy ... does the camber keep the right tension in the ski to present a consistent edge to the snow? In which case my lightness means that all I need to do is tilt the ski and go....which is what it feels like... |
Yes possibly a closely linked but hard to see analogy on my part, but the overall aim of maintaining directional control under the severest of hammering down varied terrain i think stands.
Suspension, I was racing moto-X before Suspension came into mtb etc with early yamaha monoshock framed bikes, then as more bikes followed like honda pro-link, suzuki floating system etc, they became more sophisticated in their performance.
Currently with a few old DH bikes in family, iron horse Sunday, orange 22 series, sun radical, Turner dhr et al, we've quite a few to experiment with.
My view is command of direction takes priority in both skiing and mtb, if you can fully interpret and enact where you really want to go, then alot of the other elements fall into place.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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I really do need to try some reverse camber, esp in some deep snow.....but I think as noted above I'd be disappointed at higher speeds on pisted/packed snow......so probably R.98s as a do it all ski with a minimal camber & tip rocker seem to work ok...
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| phil_w wrote: |
| I think also that the pressure needs to be consistent along the entire running length, or the ski will break away where the pressure's less. Hence decambered noses and torsional stiffness. They dick around with the stiffness at tips especially to stop them vibrating: it's not just "stiffness" which matters, it's also "damping". For completeness, the sidecut profile also has some input into this. |
Very good point there about edge/sidecut.
If the widest point of the ski were to be variously behind, matching or infront of the rocker "lift" point, then it would be applied by the skier earlier or later into their leaning the ski over from flat stance.
It could come in really fast, or slow and late dependent on placement relative to other aspects.
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| under a new name wrote: |
| @Old Fartbag, yebbut, the actual tip/tail pressure is vanishingly small. |
A good explanation re Camber from Wagner Skis:
UNDERSTANDING SKI CAMBER & ROCKER
To understand rocker and camber, it’s best to picture a ski on a flat, hard surface with the base side down. Traditional skis make contact with the ground surface in the tip and tail sections while the center of the ski is arched upwards. The two contact points often correlate to the widest parts of the shovel tip and tail. The section between these two points is essentially the ski’s effective edge. A ski’s effective edge is the section of ski that is used to make a turn, it is the length of the edge in contact with the snow when the ski is carving through a turn. As a point of reference, traditional race skis have significant camber, which helps ski racers track well on hard snow and initiate fast turns.
Ski camber reflects what you are picturing for a traditional ski, as seen in the figure above. With this ski shape, you have a longer effective edge. This translates to a more stable and controlled ride when skiing. Why? When you weight the ski, and initiate a turn, the forces you use distribute along the entire effective edge of the ski. In effect, much of the edge pressure applied to the snow is transferred out to the shovel and tail. This provides better stability, better edge grip, and precision on hard or icy surfaces. When you press the tip into the snow to help the ski “draw” into the turn, the effect is accelerated in a cambered ski, especially in moguls, where the shape of the camber helps maintain contact with the downhill face of each bump. Taken together, the longer effective edge holds a cleaner carved arc and offers a snappy transition into your next turn.
https://www.wagnerskis.com/blogs/journal/ski-camber-vs-rocker-skiers-guide
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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@Old Fartbag, nah. THe first half is just describing what camber is and the 2nd half is Wagner marketingbollocks. You don't fork out the prices of those skis for any old marketing puff!
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You'll need to Register first of course.
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| under a new name wrote: |
| @Old Fartbag, nah. THe first half is just describing what camber is and the 2nd half is Wagner marketingbollocks. You don't fork out the prices of those skis for any old marketing puff! |
Maybe you prefer it without the marketingbollocks:
Without camber, the weight at the mid-section would cause the ski to have a large pressure point under foot, making it more difficult to make ski turns. With the camber, the added weight evenly distributes throughout the ski, thereby making maneuvering of the skis easier – and adds spring to turns and pop for jumps.
Overall, it helps for a skier to control their turns. Camber gives the best edge hold and it gives each turn more power. It provides a springiness or pop into the ski every time the ski rebounds to its natural arc shape during weightless turn transitions.
https://skiprofiles.com/ski-camber-explained-whats-best-for-your-style/
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I don't think even that's getting remotely close to the mechanics correctly though.
"it helps the skier to control their turns" is a claim, it doesn't explain how. I think we can work it out, but those guys don't seem like they've done even school physics.
"gives each turn more power" is funny. They are using "power" in a marketing, not technical sense.
It's more like wine tasting notes than science.
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| phil_w wrote: |
I don't think even that's getting remotely close to the mechanics correctly though.
"it helps the skier to control their turns" is a claim, it doesn't explain how. I think we can work it out, but those guys don't seem like they've done even school physics.
"gives each turn more power" is funny. They are using "power" in a marketing, not technical sense.
It's more like wine tasting notes than science. |
Maybe this is more to your liking (which does talk about Camber)?
https://www.real-world-physics-problems.com/physics-of-skiing.html
Last edited by After all it is free  on Sat 14-01-23 15:53; edited 1 time in total
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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@phil_w,
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I don't think even that's getting remotely close to the mechanics correctly though.
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me either
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@Old Fartbag, "In other words, the ends of the ski touch the ground while the middle of the ski is elevated. This is done to control how much the ski flattens out when the weight of the skier is applied to the ski. Nope. A flat ski distributes the weight of the skier more evenly over the snow surface, which means the ski doesn't dig into the snow as much, and snow resistance is reduced. Nope. This is useful when skiing with no tilt on the skis. Alternatively, if the skis are manufactured flat, then the middle of the ski would sink more than the ends when the skier's weight is applied, Nope. and movement through the snow would be more difficult. However, the amount that the middle of the ski bends when a given weight is applied depends on the stiffness of the ski, which can vary in different skis. Remember, thumb and index finger?"
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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@under a new name, If you prefer your explanations with equations - see the "real world" physics link.
I certainly notice the difference between skiing on a ski with regular camber vs one with early rise.
The descriptions that I have found, of what a positive camber does, all say the same thing. If you completely disagree, maybe provide a link that backs up your beliefs. Just saying "Nope" doesn't make you right. 
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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@Old Fartbag, the problem is that they make no real world sense. If I can get my skis flat with 2 fingers, there's no way that's doing anything very meaningful, outside, perhaps, @ski3's high level racing context.
Feels to me like the old "ground's too warm for snow to last" nonsense, which had never made sense to me and there on new years' eve a (senior) pisteur chum confirmed my intuition.
i'm only saying "nope" to assertions that are patently ridiculous. (and that author ought to know better).
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"Nope": I think ski physics as used by most of the industry is wildly funny.
"early rise" is described pretty well in at least one snowboard patent - Kessler patented that at least a decade ago for snowboards. If you mean what I think ("decambered nose and tail"), then the basic idea is that traditionally they just "turned up" ski noses so they'd not bury themselves in snow. By the early 2000s they figured out that if you actually engineered that curve so it matched the curve the ski was likely taking through the snow in a turn... it'd work a lot better.
It's interesting to think that it took a long time for people to work out something seemingly obvious like that. I think that's because ski design was a "craft", passed from master to apprentice, not actually science-driven. If computers were designed by passing knowledge from generation to generation... we'd probably not have come quite so far quite so fast.
But then I may have just drunk some rather good South African Chenin Blanc. At 12.5% I think internet access remains safe, although time will tell.
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You know it makes sense.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| under a new name wrote: |
| @Old Fartbag, the problem is that they make no real world sense. If I can get my skis flat with 2 fingers, there's no way that's doing anything very meaningful, outside, perhaps, @ski3's high level racing context. |
... just to throw in my three penn'rth...
Prior to the carving-ski revolution in the late '90s, trad cambered-ski design had presumably just evolved from touring/travel orientated skis (cf Sondre Norheim's designs in the mid 1800s) which had a cambered mid section when the ski was unloaded and contact areas at the tip and tail, allowing kick-wax to be used in the cambered area and glide-wax at the contact tip/tail areas
So nothing much had changed for the next 100yrs or so... 
Also, advances in materials technology allow for a much more torsionally stiff ski, allowing more sidecut/wider tip & tail.
Trad cambered skis didn't have much sidecut so required bending into a -ve camber to get the curved carving edge engaged (take a straight ruler and bend it on a flat surface - there's only contact at the mid-point so you can appreciate how adding a little side-cut allows contact of the whole edge).
The pressure required to squeeze the bases together/flat is irrelevant - it's the pressure to camber the ski which is important, so the degree of difficulty squeezing the bases flat just indicated the force/stiffness required to bend the ski into an arc.
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Poster: A snowHead
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| Quote: |
| Trad cambered skis didn't have much sidecut so required bending into a -ve camber to get the curved carving edge engaged |
Lightbulb moment (?...maybe..¿) - Further to the above....
Old-Skool skiing technique relied on un-weighting when making the turn, so the return to +ve camber would presumably help with releasing the engaged edge whilst initiating the turn
Plus back in the day, turns tended to be more skidded, so probs didn't want the edge fully engaged until weighting the ski to complete the turn
..... hmmmmm?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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@geoffers, "Also, advances in materials technology allow for a much more torsionally stiff ski, allowing more sidecut/wider tip & tail."
I feel there's more in that and try to expand it with the following.
The material potential for more torsional resistance has climbed, in as much that a flatter section newer ski, against pure cross-sectional performance of thicker older ski needed before is greater. That's due to understanding of composite materials and performance of resins/bonds etc.
However, I feel that torsional rigidity at the tip width is reduced by intentionally laying up to accommodate this element of modern ski design.
To explain that. If we look at operating an old straight ski, then the mitigation of how severely the tips enacted against skier mass was to file metal from that edge such that it couldn't enact it's full bite on the snow surface.
In comparison, a modern shaped ski is deliberately trimmed with less torsion to facilitate the same, to blend away the pure bite as the designer specifically includes and negating the need to round those edges at tip and tail. Modern shaped skis are now edged the same full length with no consideration given to how those edges are used from ski tuning.
So higher performance composite structure to tailor that ski into its turning characteristics by selective reduction in applied torsional resistance, ultimately making skis targeted at different user demands/profile.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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I think that new technology that allows a more torsionally stiff ski is what Salomon claimed when they released the pocket rockets...
I did check on the DPS website, it appears the banana skis they used to sell are no longer available? Most skis they sell seem to have some camber and tip/tail rocker (Only from a quick check so could have missed a pair??). So perhaps that is quite telling?
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You need to Login to know who's really who.
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| kitenski wrote: |
I think that new technology that allows a more torsionally stiff ski is what Salomon claimed when they released the pocket rockets...
I did check on the DPS website, it appears the banana skis they used to sell are no longer available? Most skis they sell seem to have some camber and tip/tail rocker (Only from a quick check so could have missed a pair??). So perhaps that is quite telling? |
I guess that depends on the compartor when talking about ski torsion.
Natural for them to push torsional resistance upward in "expert, high performance" focused ski, compared to their previous ski models, compared to prevailing market etc.
I've sat in marketing focused meetings that explore what statements are to be included in new product releases, some of them very tenuous in technical achievements, key statements though when selling a product.
The materils are likely to perform better than previos, for the same dimensions. This would allow a reduction in materials to be used and keep that torsional response (lighter more poppy ski ?) and still claim "more torsionally stiff" as part of package.
Depending on how the marketing focused wording is sliced and diced really.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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| geoffers wrote: |
... just to throw in my three penn'rth...
Prior to the carving-ski revolution in the late '90s, trad cambered-ski design had presumably just evolved from touring/travel orientated skis (cf Sondre Norheim's designs in the mid 1800s) which had a cambered mid section when the ski was unloaded and contact areas at the tip and tail, allowing kick-wax to be used in the cambered area and glide-wax at the contact tip/tail areas Good point, so we have a bit of history as to perhaps why the initial shaping?
So nothing much had changed for the next 100yrs or so...
Also, advances in materials technology allow for a much more torsionally stiff ski, allowing more sidecut/wider tip & tail.
Trad cambered skis didn't have much sidecut so required bending into a -ve camber to get the curved carving edge engaged True, but they had enough that putting on edge and pressuring allowed at least some turning unput even if not perfectly carved (take a straight ruler and bend it on a flat surface - there's only contact at the mid-point so you can appreciate how adding a little side-cut allows contact of the whole edge).
The pressure required to squeeze the bases together/flat is irrelevant - it's the pressure to camber the ski which is important I can accept that, so the degree of difficulty squeezing the bases flat just indicated the force/stiffness required to bend the ski into an arc. I would submit that going from +ve camber to flat requires less force (well obviously) than going to significantly -ve cambered |
But other than history, this goes no further in explaining why +ve camber today ...?
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| geoffers wrote: |
| Quote: |
| Trad cambered skis didn't have much sidecut so required bending into a -ve camber to get the curved carving edge engaged |
Lightbulb moment (?...maybe..¿) - Further to the above....
Old-Skool skiing technique relied on un-weighting when making the turn (down unweighting was also a thing), so the return to +ve camber would presumably help with releasing the engaged edge whilst initiating the turn If you think about it, if significant (I don't think it is) it would actually act (I think) to keep the edges engaged. Anyway, I think this insignificant, from my recollection of carving old skool.
Plus back in the day, turns tended to be more skidded, so probs didn't want the edge fully engaged until weighting the ski to complete the turn Achieved by flattening the skis slightly, if you didn't want to carve. Again, nothing to do with +ve camber, as far as I can see?
..... hmmmmm? |
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| Quote: |
I think that new technology that allows a more torsionally stiff ski is what Salomon claimed when they released the pocket rockets...
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The Pocket Noodles you mean?
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