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  1. #51
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    Dec 2008
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    Quote Originally Posted by Quandary View Post
    That's just not accurate. Here for example are the flex numbers from two reviews that came out this summer;

    DPS Pagoda
    Tips: 8.5
    Shovels: 8-8.5
    In Front of Toe Piece: 9-9.5
    Underfoot: 10
    Behind the Heel Piece: 10-9
    Tails: 8.5-9

    K2 Reckoner
    Tips: 6
    Shovels: 6.5-7
    In Front of Toe Piece: 8-10
    Underfoot: 10
    Behind the Heel Piece: 10-8.5
    Tails: 7.5-6

    Hmmmm, looks pretty different to me. Once you have flexed a few skis that they have reviewed and have a feel for their "scale" you will find it is reliable.


    Yeah, I had a typo there. Should be "under" 6-6,5.
    And yes, they do differ between skis. My point was more that they seem to put "most" skis in the 8-9 category, and almost every ski at 10 underfoot.
    Another point would be that their scale seem a bit random. What is a 10? What would make them consider adding "11"? How soft would a ski rated 3 be?

    185cm Enforcer 93:
    Tips: 6.5
    Shovels: 7-8
    In Front of Toe Piece: 8.5-9.5
    Underfoot: 10
    Behind Heel Piece: 8.5-8
    Tails: 7

    "it is also not a seriously stiff ski" - Blister - but still half of the ski measures from 85-100% on their scale. I've skied the 93s for two seasons. It's pretty easy to handflex the entire ski - yet they are "10". The same as Wren108s and a lot of other skis - and both skis you mention above. I guess what I'm saying is that I feel they should use the entire scale. I upgraded the 93s to 88s. And they are a lot stiffer - but are rated pretty much the same for the middle of the ski.

    Disruption 82Ti:

    Tips: 9
    Shovels: 9.5
    In Front of Toe Piece: 9.5
    Underfoot: 9.5
    Behind the Heel Piece: 9.5-9
    Tails: 9.5

    "Look at those numbers — this thing is stiff!" - Blister. But not that much stiffer than the 93 in the middle......on a scale from 1-10, that is.

    But then again "To understand the flex you should look at the whole curve, not just the highest point of the arc. The middle (where the binding is mounted) is less important than the front and back area" - Endre Hals.
    Maybe the difference I feel comes mostly from the difference in tips and tails - which I feel Blister communicates better.

    On the other hand, I guess modern skis are more similar than 10 years ago. Then we had super-stiff skis from Dynastar, Rossi etc, alongside super-floppy skis from Line and K2. Probably less difference today.

    The same can be seen in the Endre Hals/SFI/FriFlyt-data. Most (again - not every) ski nowadays seem to be in the 4-6/7-range. Back in the days Bluehouse Shoots measured 11 and I think EP Pros were a 2.

    However - a 5 on the SFI scale represents the average of every ski tested. So it's not set in stone. A ski rated 5 10 years ago is probably not the same as a 5'er today.
    Another thing with the FriFlyt tests are that they (maybe) use more of their scale for a group of ski, but less for any given ski. You'll often see a 5-5-5-5-5 ski in FriFlyt. Never seen that in Blister.

    PS: Obviously, if Blister actually measure skis in some sort of machine, then I'm just way off.

    PPS: Obviously, if Blister doesn't measure skis in some sort of machine, I'm still probably way off.

  2. #52
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    Jan 2013
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    391
    Well put sf! I agree 100%.

  3. #53
    Join Date
    Feb 2009
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    113
    Good convo. Lots of manufacturers put lots of ski metrics and measurements out there - great example 4frnt with basically a ski blueprint on their site for each ski. Those measurements don't tell you everything, but they get you in the ballpark if you know camber, radius, width, rocker, taper, weight. Some stiffness metric would be great and seems quite doable - but someone's gotta start and ideally manufacturers (at least some) get on board.
    Manufacturers prob won't go for this. It really tests their manuf specs and tolerances. You see it when people post pics of camber and/or rocker that are off from what's on the website or what they saw in a shop. And with so much manufacturing farmed out, they're probably crossing their fingers when the production runs actually start showing up!
    All that said, Blister (and others too I'm sure) are way better than the old "Ski" magazine reviews that would just have a handful of reviewer quotes like "they're like rocket ships on each foot!" and "like surfing but you're on snow!" I remember being so psyched to see those issues as a kid and then just scratching my head like "what the hell does that mean" and end up just lusting on a pair based on the topsheets... Is like Ski magazine still even around?!

  4. #54
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    Aug 2014
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    2,390
    Ski Magazine (as well as Skiing Magazine) are still a thing, and the reviews haven’t gotten any better...

    Is there enough control in ski manufacturing that measuring one pair of skis for each skis of each make and model enough to come up with an idea of what that ski is? Or are the manufacturing tolerances not that tight? It does it depend on the brand? Or is that something early on that would need to be identified?


    Sent from my iPhone using TGR Forums

  5. #55
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    Skiing magazine went out of biz again, actually. Too bad, it was much better than Ski.

  6. #56
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    Quote Originally Posted by m104da View Post
    Good convo. Lots of manufacturers put lots of ski metrics and measurements out there - great example 4frnt with basically a ski blueprint on their site for each ski.
    Down is great in this respect as well

  7. #57
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    Quote Originally Posted by skibrd View Post
    Ski Magazine (as well as Skiing Magazine) are still a thing, and the reviews haven’t gotten any better...

    Is there enough control in ski manufacturing that measuring one pair of skis for each skis of each make and model enough to come up with an idea of what that ski is? Or are the manufacturing tolerances not that tight? It does it depend on the brand? Or is that something early on that would need to be identified?


    Sent from my iPhone using TGR Forums
    I would imagine it would be similar variations in stiffness as there is in weight, basically around 3 percent, or 50 grams of variation on a 2000 gram ski.

    The variation in wood grains might cause more than just manufacturing variations, but either way its probably pretty negligible.

    I would bet theres more variation from large manufacturers than from the small companies, but I don’t have anything to back me up on that.

  8. #58
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    Quote Originally Posted by gregorys View Post
    ...In the end, nearly everyone simply says "It does X like this other car." And does Y like yet another car. etc...
    Simple performance comparisons like that are what I really want to pursue for skis. But in addition to "like" above, also > and < can help someone to zero in on what they're looking for. Blister does it via their Spectrums and Deep Dives, but I want to take it much further, and in a way that's machine-readable. One challenge is that the number of A/B pairs to be compared increases factorially with the number of skis. (You know, like "exponential growth", except it's factorial.) And one impossibility is getting humans to waste many, many powder days rigorously testing powder performance (unless skiers in Japan get sick & tired of way too much powder? hahaha).

    I agree with gregorys that the fruits from measuring longitudinal stiffness & damping might not be worth the work, but it's not in my best interest to discourage anybody from trying that. I do have higher hopes that torsional stiffness could be more fruitful, but who knows?

    Quote Originally Posted by gregorys View Post
    ...But I fail to see what advantage that really has over the current system of: "The guys at Blister/TGR/BroRiders/your-fav-review-site have this review and it's pretty similar to the Katana - though you may not be able to sip your PBR while crushing chop."...
    Is that everyone's current system nowadays? hahaha

    Quote Originally Posted by sf View Post
    ...But then again "To understand the flex you should look at the whole curve, not just the highest point of the arc. The middle (where the binding is mounted) is less important than the front and back area" - Endre Hals...
    Yeah, instead of longitudinal stiffness, I'm trying fore & aft self-righting moment (measured at the boot), thinking that might end up being more fruitful. Self-righting moment at least partially captures the effect of distance from the boot (i.e. the increased importance of "the front and back area" as mentioned by Hals above), and also at least partially captures the effect of a non-flat ski geometry on a flat surface of snow (i.e. rocker, camber, reverse camber, etc).

    .
    - TRADE your heavy PROTESTS for my lightweight version at this thread

    "My biggest goal in life has always been to pursue passion and to make dreams a reality. I love my daughter, but if I had to quit my passions for her, then I would be setting the wrong example for her, and I would not be myself anymore. " -Shane

    "I'm gonna go SO OFF that NO ONE's ever gonna see what I'm gonna do!" -Saucerboy

  9. #59
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    Mar 2020
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    Quote Originally Posted by sf View Post
    PS: Obviously, if Blister actually measure skis in some sort of machine, then I'm just way off.

    PPS: Obviously, if Blister doesn't measure skis in some sort of machine, I'm still probably way off.
    My understanding is that Blister does not use a machine, but I could be completely wrong. I could find nothing in their website or the Buyers Guide that details how they arrive at the stiffness numbers. Thus the stiffness numbers are likely subjective based on hand flexing, presumably by the reviewer of that particular ski. My point was that at least Blister makes an honest attempt to judge the stiffness of each ski and relate it to the characteristics of a given skis' performance. Couple that with the Deep Dives, and your personal knowledge of skis that are being compared to the ski being reviewed, a reader can get a reasonable picture of the skis' on snow performance. As far as I am aware it is the only ski review source that makes an attempt at combining the subjective and objective, skis a ski multiple days in varied conditions and goes to these lengths to review a ski. It is certainly far better than the crap you get from any other source, which are based on a couple of runs be random reviewers.

  10. #60
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    After reading more, I'm convinced lab measurements of ski damping & vibration response are not worth the trouble at all. And likely not even valid to try to use lab measurements of damping to draw conclusions about on-snow performance.

    A very recent paper suggests that lab damping is basically ALL about mass, mass, & mass---not affected much by other attributes in skis, or even by fancy parts marketed as specialized "damping features".
    See https://www.mdpi.com/2504-3900/49/1/49/pdf
    and http://tiny.cc/4bq7fz

    And it means nothing if a super-stiff, mad-camber ski vibrates freely like crazy in the lab---because when loaded and flattened on-snow, its spring-loaded edge pressure is high enough that it will rarely lift up off the surface to ever be free to vibrate much anyway. Plenty of lab measurement methods haven't figured out how to capture the stuff that matters on snow.

    .
    - TRADE your heavy PROTESTS for my lightweight version at this thread

    "My biggest goal in life has always been to pursue passion and to make dreams a reality. I love my daughter, but if I had to quit my passions for her, then I would be setting the wrong example for her, and I would not be myself anymore. " -Shane

    "I'm gonna go SO OFF that NO ONE's ever gonna see what I'm gonna do!" -Saucerboy

  11. #61
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    I like Gregorys' car analogy. Just tell me how many cup holders and USB ports the ski has.

  12. #62
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    Sep 2015
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    I think, as I read somewhere on here somewhat recently, that the most important measurement is "how many grannies, small children and Ikon pass-holders" they'll mow down.

  13. #63
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    Aug 2020
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    Quote Originally Posted by Vitamin I View Post
    After reading more, I'm convinced lab measurements of ski damping & vibration response are not worth the trouble at all. And likely not even valid to try to use lab measurements of damping to draw conclusions about on-snow performance.

    A very recent paper suggests that lab damping is basically ALL about mass, mass, & mass---not affected much by other attributes in skis, or even by fancy parts marketed as specialized "damping features".

    And it means nothing if a super-stiff, mad-camber ski vibrates freely like crazy in the lab---because when loaded and flattened on-snow, its spring-loaded edge pressure is high enough that it will rarely lift up off the surface to ever be free to vibrate much anyway. Plenty of lab measurement methods haven't figured out how to capture the stuff that matters on snow.

    .
    Vitamin I, this paper is about what is important during a lab test. Mass is important to reduce the response to impacts in the lab. Skis are not very damp to start with. They will oscillate for 30+ cycles when you hit them in a lab. However, if you hit the same ski on the snow, you will rarely see more than 2-3 cycles. No tested damping device can match the damping of the snow.

    A "damp ski feel" is not the same thing as the "damping" definition in engineering. For skiing, it is much more important to think about how the ski interacts with the snow through the preload on the tip/tail, its mass to plough through snow, resistance to twisting during skidding, etc.

    We need more representative ways to measure the vibration response of skis in use.

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