Badminton guide Youtube channel, measured racket specs including stiffness

Discussion in 'Badminton Rackets / Equipment' started by Asmo, May 17, 2020.

  1. Asmo

    Asmo Regular Member

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    Badminton guide is a relatively new Youtube channel that measures racket specs. I've seen it mentioned in various threads here but I thought it might be good to have a separate thread to collect and discuss their measurements. Of particular interest is that they attempt to objectively measure stiffness which I think is the first place I've seen that does that for badminton rackets. Every other review or mention of stiffness I've seen has been more or less completely subjective opinion with no hard data. Or just the manufacturers often very vague rating. They also have some other measurements you usually don't see like shaft and frame thickness. Unfortunately they don't measure swing weight but Racquetforce does a pretty good job of that on their Facebook page.

    The first thing to discuss is how accurate or meaningful their stiffness measurement actually is. Here is a video describing how they do the measurements, not in great detail for the stiffness unfortunately. But it seems they apply a fixed force or weight to the top of the frame and measure how much it bends. After googling it a bit that does seem to be a method also used for tennis and that I can't really see any big issue with? The biggest concerns I found are that it doesn't say anything about where the frame bends. Also it gives a static stiffness value which apparently might not be completely representative of the dynamic flex of a frame during a stroke. Still it should give a pretty accurate repeatable value that is much better than not having any objective value to compare with at all. Especially between different manufacturers.

    So here are a couple measurements for some of the more popular rackets. They're starting to build up a pretty good database.



    Stiffness ratings for some other rackets
    Yonex Voltric Z-force II - 8.3
    Li-ning
    Aeronaut 9000 - 8.7
    Aeronaut 9000c - 8.5
    Aeronaut 9000d - 8.8

    Some pretty interesting results. For example that Astrox 99 should be clearly stiffer than 88. 88d actually less stiff than 77. 100zz pretty much the stiffest racket ever, more than ZF II. Also that the 100ZX should be way head heavier than 100ZZ. Aeronaut 9000 series that are genereally considered less stiff than Yonex should be very similar to Astrox 88. Interesting also that their measurements don't align with Li-nings official rating of them with the 9000d actually being the softest.
     
  2. Martynas

    Martynas Regular Member

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    probably my other racket will be only after these guys review it, so I think they are doing very great job there, and as long as they keep the same measure practices it does not matter that much how they do it, since it is way more important how one racket compares to another. Then only swing weight without overall weight does not matter that much as well, so their measure of weight with the same setup always and BP gives way more information how racket would behave than only swing weight. And those discrepancies does not surprise me at all since all big three brands give basically 0 quantitative specs (may be lining a bit more) they can produce like whatever they want, and 100zz has the longest handle of all - so I am not surprised that it would play the stiffest (since z-strike has not so long handle it has even more stiff shaft)
     
  3. visor

    visor Regular Member

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    88D is much stiffer than 77.

    Sent from my SM-G988W using Tapatalk
     
  4. Coolkas

    Coolkas Regular Member

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    I dont know why but i still cant trust his stiffness rating, because some of the racket i have does differently from the vid, but BP weight other is more or less the same
     
  5. Asmo

    Asmo Regular Member

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    Well it is of course possible that the shaft flexibility value they provide is more or less useless and doesn't tell us anything meaningful. Which would be a shame. Basically I can see two reasons for why that might be 1.The way they measure it has too high margin of error so it gives unreliable data. 2.This method of measuring stiffness is fundamentally flawed and doesn't correlate to how the rackets actually feel when playing.

    I'd say nr2 is more likely since they seem pretty meticulous in their other measurements. Like I said I found a couple concerns about this method when being used for tennis, but it seemed to still be considered at least somewhat valuable. It might be that for some reason it doesn't work as well for badminton rackets. It doesn't say anything about where the racket bends which maybe makes a noticeable difference. The other concern is that a static flexibility measurement doesn't accurately represent how the racket behaves during a stroke. For example it maybe doesn’t flex linearly and doesn’t factor in how fast it snaps back. That is basically the Astrox marketing that they’re supposed to feel stiff but still flex and give you power when you need it. I’m a bit skeptical of that but maybe there is at least some truth to it.

    Here is a video showing how this type of measurement can be done or with this Babolat machine which seems to be the more common way.
     
    biborinho and Coolkas like this.
  6. endFX

    endFX Regular Member

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    BadmintonRacketReview does this kind of measurements as well. You have to pay to access all data but often you can find things like bp and stiffness in their free YouTube videos.
     
  7. Asmo

    Asmo Regular Member

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    Interesting I didn't know Racketreview did a stiffness measurement. I've seen a couple of their Youtube videos but I have to say I got a really bad impression from them so I basically wrote them off and hadn't seen their newer where they show a stiffness rating. For example that he doesn't seem to understand that everyone else in the industry lists weights unstrung and still seems surprised every time his weight measurement doesn't match. Or that part where they try to give the rackets accuracy scores and what not and hit shuttles in to buckets seemed like a bit of a joke. But I see they do actually appear to have some good real data behind the paywall like stiffness and swing weight.

    Anyway I compared a couple rackets that both Racketreview and badminton guide had measured and yeah their stiffness measurements don't agree at all. So at least one or probably both aren't accurate. You only see a zoomed in picture and can't really tell how Racketreview is doing the measurement, I guess the info might be behind the paywall? The value they give is in grams and the difference between rackets seem to be in the order of 1/100th of a gram with higher meaning stiffer. Which seems pretty strange and doesn't match any of the methods I've seen like the two I linked above.

    So I think we can conclude that the stiffness rating from Badminton guide should be taken with a big pinch of salt. Even without the stiffness Badminton guide has some good info on balance points etc that does seem to be thoroughly and consistently measured and they post new rackets every few days for free. So I still think they provide a valuable service that I’m grateful for.
     
    #7 Asmo, May 21, 2020
    Last edited: Aug 30, 2020
  8. Budi

    Budi Regular Member

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    Now it makes me wonder, who makes a standard 81-85gr is 4U, 86-90 is 3U?
    If its BWF, why they didnt set a standard for stiffness to?
    Some brand just say stiff, flex, extra stiff.
    Some other come out with number 8.0, 8.5, 9.0.
    Some other use a bar drawing. 5/5 for the stiffest, or adidad use 7 or 9 bar if im corrrect, tho their catalouge come out with number to.

    Or does measuring stiffness is much more complicated to do to put a standard?
     
  9. Martynas

    Martynas Regular Member

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    even if badminton guide is not accurate, but as long it is the same inaccurate for all rackets (and for badminton guide reviews it is the case) and you can compare one racket to another, it is more than enough, and if someones feeling does not match measurement, it is most likely not measurement problem.
     
  10. Asmo

    Asmo Regular Member

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    One of their more interesting findings lately I saw was that there does indeed appear to be a difference between blue and yellow Astrox 77. I have personally mostly written of claims of different specs for different colors of rackets as either placebo or normal manufacturing variances. At least if they've been released simultaneously.

    But here they tested both the 3u and 4u versions and got a consistent 7 and 6mm higher balance points on the yellow. It would of course have been better if they tested several copies to make sure but since they got such consistent results with a relatively large difference I'd say it does pretty strongly indicate the difference is real.

     
  11. Yaremchuk

    Yaremchuk Regular Member

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    Great channel - Badminton Guide!

    I'm gonna take their numbers into a spreadsheet for my personal references.
    And I definitely am choosing the next racket using their data.

    That's a pity that there are lots of unrelated rackets, like Apacs, Karakals as we don't have them sold locally.

    I'm also planning to do my own measurements and I'm going to try and align them with Badminton Guide's.
    For that I'll need 2 different rackets measured by BG then I measure them myself and then I can calibrate all my other measurements.
     

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