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Ski Physics and soft snow performance - Page 2

post #31 of 51
Quote:
Originally Posted by Cirquerider
None of this discussion seemed to exist here 2 years ago. It was all about super sidecuts and short skis. Now both have their role, but the tide has definitely turned, at least in the West.
Alot of it has to do with personal preference. I dislike the wide long boards with little sidecut. I'd much rather have a turny ski.
post #32 of 51
Quote:
Originally Posted by mudfoot
I can see where a wide soft tip would work well for an intemediate venturing into the ungroomed because it allows them to maintain their usual stance and not force them to sit back to make the ski float, but I think as your speed increases in powder or crud the soft wide tip looses stability and starts become a liability. I would agree that "for most people... they turn out to be more versatile for them," but I think you are talking about a basically groomed run ski that does a pretty good job of not diving in deep snow, as opposed to a good ski for off piste. To say the "Metron series works so well in soft at shorter lengths" would have to be qualified as applying to intermediate skiers or those going at slower speeds. I believe that any serious off-piste skier would not be wanting a short radical sidecut ski, but just the opposite because of the increased float and stability. Obviously straighter is only better in deep snow up to a point, since the sidecut does play a role in shaping the turn, but a much lesser one than on the groomed.
Sure, for an AT setup no one is gonna mount up an MB5, but to say that the upper end of the metron seiries is a groomed run ski or that the supple tip on the MB5 leads to instability in powder or at speed is just plain wrong in my book. I teach in hike to terrain 2-3 times and I really appreciate the versatility and stability that my MB5's bring to the table. Yeah, when it gets deeper than my knees, I want my suggar daddys, but in everything else, I'll opt for the MB5's. When freeskiing, I doubt that I spend more than 20% of my time on groomers, wiht most of this relegated getting back to the lift. When teaching, the ratio goes up of course, but I teach plenty off the groom.

I don't see this as an east/west thing but probably more a difference in technique and choices between sidecut to manage versus extra steering input. Both are very valid ways to approach skiing. My expereience has lead me to the sidecut side of the equation for most of my skiing. later, RicB.
post #33 of 51
Quote:
Originally Posted by Ghost
This makes sense to me. I also have a suspicion that when metron owners claim the ski works well at high speeds that they are not ex Downhill Racers, if you get my drift.

Simply put the wider tip will prevent tip dive and more than make up for the narrower waist, and the skis will be easier to ski at slower speeds. The less radical sidecut will work better at higher speeds.
You are right ghost, I'm not an ex downhill racer. I don't ski really fast, nor do I ski slow. I do ski all the mountain in all conditions, and I do have much backcountry expereince on old school gear in Soutwest Montana. How about explaining your drift to me so I can understand better. later, RicB.
post #34 of 51
In the old days the only top end skis were race skis. You only had a choice of 3 types if you wanted real perfomrance, Slalom, GS or Downhill. When Head came out with its 360 model around 1970 it was hailed as the frist "all-round" ski. Since then skis have gone through hundreds of construction changes and length trends, all called "advances," and although some more width has improved performance it seems to me the flex and sidecut radius of a well perfoming ski has not really changed.

When I grew up skiing in Wisconsin there were short hills and long lift lines, and skiing was about making as many turns as possible. When I moved to Montana (land of no lift lines and wide open runs) I got invited on trip with some patrolman to ski on their day off. Every run they were at the bottom waiting while I was still up there turning like crazy. They probably made 1/4 the number of turns I did on the same run. By the end of the season my style had evolved to match theirs but the experience illustrated how skiing is not the same thing for everyone.

RickB: I did not intend to get into Metron bashing. A good skier can make almost any ski work in almost any condition, so it really comes down to personal preference. The B5 is one of the best all round skis but IMHO it goes too far in the wide tip narrow waist department. It sounds like it works for you in the crud. If you are skiing "hike to terrain" at Birdger or Big Sky then you are probably in very steep terrain and making very tight turns
post #35 of 51
The standard thought progression for many Metron owners:

1. "Gee, the groomers sure on fun on my K2 Fours! I think I'll stick here."
2. "Well, the K2s are getting old. I guess it probably time to buy some new skis."
3. "Atomic is pushing this new Metron line... but a 70+ waist? That's a powder ski by my standards!"
4. "Wow, these crazy powder skis really work well on the groomed! Who knew a 75mm ski could be quick edge to edge?"
5. "I guess since these are powder skis I should try some off-piste stuff...."
6. "Hey, this is fun! These skis are AWESOME off-piste! Best crud/powder skis ever!"
7. "I'm gonna tell the entire world how awesome these metrons are on this message board!"

Basically, most Metron skiers are one ski people. They've skied on one ski in every condition since they began, and that one ski is invariably a mid to high performance carving ski in he 65-69mm range. All of a sudden, they're being told that, yes, a wider platform can add stability to a carver and still perform just as well. They're tempted to try new terrain by this newfound stability and becasue, hey, they think they've finally got the appropriate tool to. A few inches of busted up crud or light powder later, and they realize that there is fun to be had outside of their normal groomed territory. Since they had fun there, suddenly the Metron is an end all, be all ski for every condition, and they're gonna tell everyone they know that they're wasting their time on big skis, because the solution is right here: the Atomic Metron.

Don't let yourelf be fooled; all-mountain ski still refers to the fact that the ski performs at an average level everywhere on the mountain. The little misdirection didnt just work for the metron though; look at the praise received by the Volkl Karma, the original Rossi Bandit, etc. The top echelon of all-mountain skis will forever be raved about by intermediate skiers as the greatest skis of the year, and since that makes up the largest portion of skiers, it'll look like everyone loves them.

Yeah, they perform well on groomed and in crud and are decent in pow, but if you're looking at any metron or allmountain ski as a soft snow ski, you're cheating yourself.
post #36 of 51
Quote:
Originally Posted by Cirquerider
None of this discussion seemed to exist here 2 years ago. It was all about super sidecuts and short skis. Now both have their role, but the tide has definitely turned, at least in the West.
Two years ago I was skiing on a 70-m turn radius ski. I heard the buz, did the demos, and bought a short-turning ski. It was fun. Now the novelty is beginning to wear off, and I'm thinking maybe it's time for something in between, say 35 m?
post #37 of 51
Quote:
Originally Posted by RicB
You are right ghost, I'm not an ex downhill racer. I don't ski really fast, nor do I ski slow. I do ski all the mountain in all conditions, and I do have much backcountry expereince on old school gear in Soutwest Montana. How about explaining your drift to me so I can understand better. later, RicB.
My drift is that the term "high speed" is ambiguous and usually has a different meaning depending on the past experience of the users. It could mean 45 mph or 90 mph. I'm guessing that when a metron owner says it performs well at high speeds, he means at 45 mph.
post #38 of 51
Thread Starter 
Quote:
Originally Posted by Takecontrol618
Yeah, they perform well on groomed and in crud and are decent in pow, but if you're looking at any metron or allmountain ski as a soft snow ski, you're cheating yourself.
I don't think very many people here see the Metron as a soft snow ski in the pure sense of the word. As you noted it is a ski that does well on the groomers and handles soft snow. For me and others it is a great ski because it enables me to ski both the groomed and ungroomed runs well without having to change skis.

I agree that it is not a powder ski per se. It is a ski that works in powder.

A side note. It is not just the intermediates who sing the praises of the Metron and other all mountain/mid fat skis.
post #39 of 51
> The top echelon of all-mountain skis will forever
> be raved about by intermediate skiers as the greatest
> skis of the year, and since that makes up the largest
> portion of skiers, it'll look like everyone loves them.


Obviously, the above statement by Takecontrol618 doesn’t apply to EpicSki participants and other advanced skiers who demo lots of skis each year, own quivers, and, in a knowledgeable manner decide to use their Metrons (or equivalent) for much of their skiing. However, I think that TakeControl618 (TC6) sized up the situation correctly for the countless number of intermediate->advanced recreational skiers who ski on one pair and in a well-intentioned but uninformed way extol the virtues of that particular model to anyone within range of their vocal chords.

They do this because their current pair performs better than anything they have previously owned and because it obviously has a broader performance envelope, NOT because they have carefully compared this pair to other modern skis, especially skis of different types.

It’s a noble goal to try to reduce the number of skis in your quiver and stay on one pair as much as possible, but at some point you decide that the tradeoff you are making by having fewer skis in your quiver costs too much in terms of performance, and so, you don’t reduce your quiver further. Some folks can be happy with a 1 ski quiver; others need more skis to be happy.

I used to be a serious gear head (and probably could easily revert back), but I’ve found that one Metron-like pair (supersidecut, short, stiff, heavy, ~70 mm wide), and some Explosivs (mid-90's in width and minimal sidecut) handle 95% of what I like to do (including teaching). OTOH, I don’t race, don’t freeheel, etc..

Obviously, YMMV

Tom / PM
post #40 of 51
Quote:
Originally Posted by mudfoot
In the old days the only top end skis were race skis. You only had a choice of 3 types if you wanted real perfomrance, Slalom, GS or Downhill. When Head came out with its 360 model around 1970 it was hailed as the frist "all-round" ski. Since then skis have gone through hundreds of construction changes and length trends, all called "advances," and although some more width has improved performance it seems to me the flex and sidecut radius of a well perfoming ski has not really changed.

When I grew up skiing in Wisconsin there were short hills and long lift lines, and skiing was about making as many turns as possible. When I moved to Montana (land of no lift lines and wide open runs) I got invited on trip with some patrolman to ski on their day off. Every run they were at the bottom waiting while I was still up there turning like crazy. They probably made 1/4 the number of turns I did on the same run. By the end of the season my style had evolved to match theirs but the experience illustrated how skiing is not the same thing for everyone.

RickB: I did not intend to get into Metron bashing. A good skier can make almost any ski work in almost any condition, so it really comes down to personal preference. The B5 is one of the best all round skis but IMHO it goes too far in the wide tip narrow waist department. It sounds like it works for you in the crud. If you are skiing "hike to terrain" at Birdger or Big Sky then you are probably in very steep terrain and making very tight turns
Overskiing the terrain is an issue for alot of skiers. Even on my metrons I tend to make way fewer turns than most of my students, who usually have skis that have considerably less sidecut. The whole sidecut issue is a little over emphasized in my oppion. Sidecut, straight or radical, only restricts when we don't have the ability to manage it to accomplish whatever we want as far as turn shape.

We can approach this by saying if we find ourselves with our ski's sidecut dictating our turn shape, we need longer radius, or we could simply learn to manage the sidecut more effectively. This also applies to straighter skis too.

Ghost, My personal speed limit has changed little over the years. Whether I was on my old Kastle Green Machines 205's years ago, to the present. I have no idea how fast this is. Really don't care, but I am sure it is nowhere near 90.

Tom, I have slowly gravitated to a two ski quiver myself. If I wasn't teaching, i might find the time to switch it up more. I do own park skis also, and will add another pair or two next season. I have generaly gravitated to one main pair over the years. though. Later, RicB.
post #41 of 51
Quote:
Originally Posted by RicB
Overskiing the terrain is an issue for alot of skiers. Even on my metrons I tend to make way fewer turns than most of my students, who usually have skis that have considerably less sidecut.
I can't think of a single run in the last 2 seasons where I wanted less sidecut than my Metron B5s have. I'll admit that I've wanted more length in some deep crud, but never less sidecut.
post #42 of 51
Quote:
Originally Posted by SNPete
Looking at two skis. One has the dimensions of 124-74-108. The other ski is 116-78-105. . . . All things being equal, which ski will do better in soft snow? As in turning and floatation.
Getting back to the origianl question, I'm still voting for the ski with a smaller tip, less sidecut and a bigger waist, which doesn't sound like a Metron B5.
post #43 of 51
Interesting outlook on which ski is preferred. Member when you only had 1 long skinny pair and they worked. I have a couple of skis and prefer 16M or less most of the time. Why? Conditions and Terrain. For me a damp wide ski with a big cut and a killer edgehold. Different ski alittle different ski technique. Enjoy the ride. Sides we all know it's the skier right.
post #44 of 51
I skiied on straight skiis for 30plus yrs and didn't know i needed to have fat skis to ski the whole mountain
I still don't think it is as necessary as some think.
If the Metron can ski the whole mountain and still retain a good hard snow performance why would you fault the buyer of such a ski.
Maybe they can ski the whole mountin on them , and maybe they have always skiied the whole mountain and just like them for their versatility

P.s. I don't own Metron B-5's but i may try them again now that you got me started.
post #45 of 51
Thread Starter 
Quote:
Originally Posted by GarryZ
If the Metron can ski the whole mountain and still retain a good hard snow performance why would you fault the buyer of such a ski.
Maybe they can ski the whole mountin on them , and maybe they have always skiied the whole mountain and just like them for their versatility

.
Good point. If one does not like Metrons, then don't buy one. Ski what you like and rejoice that other skiers have found skis that they love.

As Harley owners are quick to say: let those who ride decide.
post #46 of 51
this thread wasn't a matter of having one ski that can perform at a mediocre level everywhere on the mountain- It was asking about soft snow performance. You might be able to arc groomers all day long on a pair of metrons, but if you're looking to add to your quiver with a ski for soft stuff, why would you even consider a metron? It's a one-ski quiver type ski. I guess the way to best explain my stance on this is to use a number system- say 1 is glare ice and 10 is bottomless blower pow. A pair of carving skis like a Volkl 5star might perform well on 1.5 to 4 type snow. The metrons then could be said to perform "well" on 2-5 type snow and then decently on snow that would closer to 6. Why buy a product with that much overla when you could buy a true midfat with a waist in the mid 80s that'll do you for a range more along the lines of 3 all the way up to 7 or 8?
post #47 of 51
Thread Starter 
Quote:
Originally Posted by Takecontrol618
this thread wasn't a matter of having one ski that can perform at a mediocre level everywhere on the mountain- It was asking about soft snow performance. You might be able to arc groomers all day long on a pair of metrons, but if you're looking to add to your quiver with a ski for soft stuff, why would you even consider a metron? It's a one-ski quiver type ski. I guess the way to best explain my stance on this is to use a number system- say 1 is glare ice and 10 is bottomless blower pow. A pair of carving skis like a Volkl 5star might perform well on 1.5 to 4 type snow. The metrons then could be said to perform "well" on 2-5 type snow and then decently on snow that would closer to 6. Why buy a product with that much overla when you could buy a true midfat with a waist in the mid 80s that'll do you for a range more along the lines of 3 all the way up to 7 or 8?
I see what you are saying, but really all I wanted was to understand an aspect of what makes skis do what they do.

In a perfect world, I suppose I would own three skis. A carver, a mid fat and a powder ski. But there is the "wife" factor. I "stumbled" into my Metron as a result of a chance demo.

Truthfully, I really only wanted to understand the dynamics of the shape of skis in this thread. The fact that it turned into a discussion about the virtues of the Metron type of ski is most interesting. From what I have read, I feel I made a good choice by buying my M9. But that was not what I was after in this thread.

Being new to the sport, I am fascinated (sp?) by all of this.

Funny how threads flow. :
post #48 of 51
Well, to give you a straight up answer to your original question, a larger tip will be deflected more easily in soft snow, causing the ski to feel "turnier." A smaller tip in relation to the waist will make the ski feel more stable. The waist width will remain the best indicator of float, simply because it will indicate more surface area in general. If I were really up to it, I suppose I could do some integrals and figure out the surface area of each, but I've been in summer mode for 3 weeks now and not exactly ready to get into all of that again.
post #49 of 51

Ski design criteria for variable conditions

TC6, if you want a fairly accurate estimate of the load bearing area of a ski, you don't have to do any integrals yourself. You can either use:

1) A spreadsheet I posted some time ago - http://www.websurd.com/epic2004/PMSidecutRadCalc.xls (column "I"). Described in this thread: http://forums.epicski.com/showthread.php?t=2681

2) Or, do it yourself in a couple of quick calculations with either the trapezoid rule:

A = Effective_length * ( tip_width/4 + waist/2 + tail_width/4 )

or Simpson's Rule:

A = Effective_length * ( tip_width/6 + 2*waist/3 + tail_width/6 )

Note that in both calculations, the waist width is always weighted much more heavily than either the tip or tail widths. This is one of several reasons why I think that most good skiers simply use waist width as the primary classifier when thinking about floatation issues. Tip and tail dimensions count, just not as heavily.

===================

With respect to the question of what is the optimal shape for a ski to give good performance over the widest range of conditions, many people have commented that skis with larger sidecut radii are deflected less by variable snow conditions (eg, cut-up crud). This statement is absolutely correct, as far as it goes.

However, imagine what happens when a ski goes back and forth between hard snow and soft snow. In hard snow carved turns, the radius of curvature of the turn is determined primarily by the sidecut radius, edge angle, etc. - assuming the ski is not absurdly stiff.

OTOH, in soft snow carved turns, you are supported by the base of the ski, not the edge, and the radius of curvature of the turn is determined primarily by the depth to which the ski flexes longitudinally, ie, the radius of longitudinal flexure.

In this case, that the optimal design for a crud ski is not just simply "straighter is better", but a ski in which the range of hard snow turn radii (for a given skier weight, g-force in the turns, skier ability w.r.t. carving, etc.) significantly overlaps the soft snow turn radii for that ski, assuming the same skier weight, etc.., AND that the range for both radii matches the desires and abilities of the skier (ie, not too long of a turning radius for skiing the trees or a more timid skier in open places, not too short of a turning radius for a big mountain charger).

Using this design criterion, you won't have a ski that suddenly hooks up or washes out on you either as you go from soft to hard snow OR visa versa. Thus, you won't get stuck with a Spatula-like ski that can't buy a carved turn on hard areas, or a short radius groomer specialist that hooks up way too much when you ski into an area of deeper snow and start to ride your bases, not your edges.

Although I haven't done the measurements to confirm this, I suspect that the reason many very good skiers love the B5 is that although the waist width is modest, it does a good job in meeting the above criteria. Specifically, it's stiff enough (especially in shorter lengths) that when the ultra wide tip encounters a pile of crud, it doesn't suddenly cause the overall longitudinal flex of the ski to increase (ie, "hook up"). Thus, it's "performance envelope" is wider than many other skis, and acceptably wide for these folks to use it as their primary ski.

Just my $0.02,

Tom / PM

PS (in edit) - The above discussion assumes a good skier who is carving most of his/her turns, whether on hard or soft snow. If you are skiing crud with a heavily smeared component to your turns (either because of conditions or skill), not only will you be having a much tougher time of it compared to carving in crud, but the above design criterion simply doesn't apply.

In smeared turns, skis have a relatively large sideways velocity over the snow. Skiing like this, when the ultra wide tip of a B5-like ski hits a pile of crud sideways (and the waist does not), your skis will be strongly torqued to your left or right. For such skiers (or conditions), the above argument doesn't apply, and a smaller tip will always lead to less buffetting / twitchiness / better "stability", etc.. OTOH, when you can arc 'em, the previous design criterion (ie, match carved turn radii) is applicable and different skis will shine.
post #50 of 51
Tom, Your discussion really helps to move along the discussion of how skis with different sidecuts and flex (stiffness) behave differently in hard and soft snow conditions. Thanks for taking the time.

In addition to the focus on the wide tip, the flare to the tail is also important. In carved turns, a tail that is wide compared to the waist also hooks up. This can produce a rounded flex that is very desirable for carving, but may be a drawback for skiers that want to release the tail in situations such as steep bumps or chutes. A carved turn is a wonderful and fun thing, but I have not found it to be what I want in all situations. Also, on very steep slopes where technical skiing is employed to set a platform for a peddle turn or hop turn, a ski with a lot of side cut only engages at the tip and tail leaving the waist suspended and bouncing over space. Since I dont straight-line many steep chutes, excessive sidecut has been a drawback in these situations as well.

Like yourself, I find I want a carving ski for certain conditions and an off-piste specialist. The Explosiv remains one of the best all-time skis in the off-piste category. While I enjoy the sidecut on the Mantra for certain tasks, and versitility in hard /soft snow conditions, I increasing find I would prefer less sidecut for this venue.

Edit: Overall I have really enjoyed the Mantra and it is my daily go-to ski. Most of my stability problems with the Mantra in crud, I attribute to the use of Fritschi Freeride bindings which elevate me 2-inches off the ski. Also, there are no problems for me as long as turns are carved. When I start going uber fast or sideslip in turns, I get unexpected hookups. This is mostly from my futile attempts to keep up with 20-something year old kids and doing things I probably shouldn't. My goal for next year is to get another side ski and mount it with alpine bindings. I am looking at stiffer skis with less sidecut and about 100 mm at the waist.
post #51 of 51
Thread Starter 
Tom, your post was excellent. You gave me the formula to detemine the answer to my "all things considered" question. And your info re. the other factors really helps me in my understanding also

I did the math. My two hypothetical skis are nearly identical in terms of their surface area/load bearing.
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