let's together answer : what is the ideal tension?

Discussion in 'Badminton String' started by kwun, Nov 14, 2003.

  1. pepe54

    pepe54 Regular Member

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    @kttcn
    Actually, I do agree with your theory. Higher tensions and stiff racquet combinations yield a better return up to a certain point assuming that the user generates a sufficiently large amount of hitting force. The idea was backed and pointed out by several reputable bc users who use high tensions on a regular basis like DinkALot. The results from your test alone would suggest that the ideal tension for your current condition would be 28 lbs ; my own findings on the matter concurr.

    In short, I guess the general advice would be to try a range of different tensions under the same test conditions and to pick whatever feels best / achieves your ideal hitting range. As for my own limited experience as a beginner, I started out at 29*31 lbs with a stiff racquet and found my ideal tension at 28lbs. My current spare racquet is too flexible and lossy, at a miserable 24lbs ; power is loss upon impact as the shaft continues bending further, rather than staying rigid during impact.

    Speed and power however, might be entirely different I suspect. Due to the nature of shuttlecock designs and aerodynamics, typically most shuttles 'restore' and experience a significant slowdown in speed. It starts out at a whopping 300+kmh initial speed but drops down to a sunday coast at 80kmh by the time its in the recepient's court. In that respect, the power of a shot relates to how much momentum or force that was imparted to the shuttle upon striking it. This has a huge influence on its initial speed but a lesser influence over time as the shuttle 'restores' and drags down to a crawl. Disclaimer: I'm not an expert in the field of aerodynamics or momentum physics, these are just my own interpretations of the mechanics at play here which might be subjective or incorrect lol :D
     
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  2. Sianturi

    Sianturi Regular Member

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    I just found an interesting research on badminton string tension which takes into account the human factor (i.e. skill level of the players):

    Perceiving the affordance of string tension for power strokes in badminton: Expertise allows effective use of all string tensions

    You can download the full pdf text. It goes back to 2013, using YY NS9000 as one of the racquets. The player skills are categorized in 3 levels:
    • Novice
    • Recreational
    • Expert
    The results are very interesting:
    • for novice players, (shuttlecock's) speeds peaked at the lowest level of string tension.
    • for recreational players, it seems that there is an optimal string tension (parabolic curve, with max speed at around 28 lbs in the 1st figure)
    • for expert players, speeds exhibited no significant variation across different string tensions.
    What is more interesting, is that although expert players can generate same speed for different string tensions, this paper explains why they choose higher tension. Here is the excerpt:

    "In producing a power stroke, novice players merely used elbow flexion and extension with little follow through after striking. Skilled players performed strokes quite differently than less skilled players. Both recreational and expert players used a full body motion starting with a side stance, then
    swinging the racquet in a series of movements at major joints starting with the ankle and knee, and proceeding up to wrist and finger joints proximal to the racquet. These motions were similar to those exhibited in long distance over-arm throwing which entail a well-timed sequence of movements along these adjacent joints. This timing is acquired through the extensive practice that eventually yields expert performance.
    ...
    Expert players were also able to produce faster racquet speeds as were the recreational players, but obviously, they were doing something more to enable them to maintain the resulting high shuttlecock speeds despite variations in string tensions. Presumably, expert players were able to use wrist and finger flexion to increase speed at the racquet head even more to compensate for the loss of energy when using lower string tensions.
    ...
    In our case, the perception of lower string tensions by expert players stimulated the expert motor system to alter the striking motion by increasing the flexion of wrist and fingers during impact, so that the additional speed can be generated to maintain high speed of the shuttlecock after impact. However, this method for generating additional speed comes with a cost: it takes more energy and may cause fatigue. For this reason, high string tensions are preferred by the experts."

    You should read the full paper. Very interesting. I just wish that the paper includes the effect of racquet's stiffness.
     
    #522 Sianturi, Mar 22, 2017
    Last edited: Mar 26, 2017
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  3. pepe54

    pepe54 Regular Member

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    Adding onto the above discussion, I have juxtaposed the two opposing philosophies in a post, comparing actual, data driven research against some other very silly views out there insistent on misleading us folks. You can find the original thread here:

    I'd respectfully disagree due to the nature of quantifiable and absolute values outweighing subjective and personal opinions. Machines record values, value A is larger than value B, humans interpret based on feelings, emotions and are influenced heavily by perceptions. I don't know if you read the entire paper, skimmed it, or glanced at the graph then interpreted the results incorrectly, but I have direct-quoted the relevant sections below. The effect of string tension on striking performance
    was examined as a function of expertise, not as a function of tension, which to my guess, is how you interpreted the results. Still, the wording in the discussion is quite clear.

    As Paul Stewert himself points out, it is a well known trend that a great divide exists between the western and eastern philosophies of ideal tensions and the trend for westeners seems to be "lower is better" while the opposite belief holds true in Asia. Given his recent article depicting his views on the topic, I'd say he has a dislike and a certain bias against higher tensions but thats just my own subjective opinion on his views from its title alone of : Why Egos and Incorrect Information About String Tensions In Badminton Could Be Doing More Harm Than Good" .

    Quoting Paul: "My concern here is that young players are being given the wrong information, backed up by over-zealous players in far-east who contribute to the badminton forums." Further on, he expresses some vastly different tension values to what the hard, data driven numbers suggest. Paul: "A highly accomplished player may find that their tensions need to be 24lbs before they notice a leveling out on power. A lower level player may find that this is way too high and 20/21 lbs is a max. " He then proceeds to recommend the following tensions:
    • Beginner – 16lbs – 18lbs – especially if playing with plastic shuttles

    • Beginner – 17lbs-19lbs if playing with feathers

    • Intermediate – 18lbs -20lbs

    • Advanced – 20lbs-22lbs

    • County/International – 23lbs – 25lbs
    (values taken from Paul's article:)

    In stark contrast, the ACTUAL data, read by machines, using a prescribed methodology says the following :
    Note that novice players are defined as "those who have not played badminton before nor other racquet sports" while recreational players are defined as "those who have experience with badminton, or other similar racquet sports" and play occasionally". A tennis player or squash player with no badminton experience, qualifies as a recreational player by definition.

    [​IMG]
    Figure 1. Mean maximum shuttlecock speed after impact as a function of string tension and skill level. Novice players ( fi lled squares), recreational players ( fi lled triangles), and expert players ( fi lled circles). Error bars are standard errors.

    You can obtain a full copy of the research whitepaper here: Perceiving The Affordance Of String Tensions For Power Strokes In Badminton

    As for my own opinion, I think the tensions Paul suggests, of 16 - 22 lbs up to the advanced level of players, are frankly quite suitable for nothing other than backyard badminton, or for first experience beginners new to badminton. My intention is not to bag Paul for his views here (to which he is perfectly entitled to them), just the fact that I'd much rather look at hard data driven evidence written in the Journal of Sports Science, than say annecdoctal stories, or personal views. Not that my own subjective views or experiences are worth much but I was flabbergasted and disturbed when I had a hit with a friends identical ZF2 which was strung at 22lbs and using thinner strings at that!. The switch turned my backhand clears into half assed backhand drops - those which invite a net kill response. Needless to say, I switched back to my own 28lbs ZF2, but was agitated for the remainder of my match, knowing that my opponent was severely handicapped and knowing why his backhands were non satisfactory. These ridiculous, mickey mouse like tensions, are not particularly useful when your trying to belt a fast drive from end to end, or making an effort to drill down an opponents defense. I honestly was ready to rip someones head off after hearing that tension. It was a borderline, offensive insult to me and kudos to my handicapped opponent for putting up with that horrid pos.

    Lastly, the research whitepaper also investigated the effects of human perception on ideal string tensions. I find it slightly comical that Paul seems to contradict his entire argument by recommending higher tensions for feather shuttles, given that plastics fly further than feathers (ie it requires more force to hit feathers the same distance:

    It found that:

    Bottom line? Subjective, perceptions are worthless to some degree imho.

    So perhaps, even Paul, with his professional coaching credentials, is mistaken by his perception, not to mention his local climate, playing hall, shuttle speeds are all entirely different environmental setups to those in Asia. Colder climates demand faster shuttles of speeds 78 and above. Warmer climates on the other hand see speeds of 76 thereabouts.

    To quash the myth once and for all, one only has to look at what sort of tensions professional players are using; Jan Jorgensen, Chen Long, Lee Chone Wei, Lin Dan, Victor Axelsen and so forth are all in the range of 30 - 36 lbs among various venues all over the world, regardless of environment specifics. It is also worth highlighting the fact that it is common for players to drop 1-3 lbs for "slow" venues as suggested, not 5lbs or 10lbs; no more ridiculous and infuriating recommendations of 16-22lbs please.

    Do these tension choices among professionals agree with what the research suggests? I believe so. Do Paul's recommendations of 23-25 lbs for these players hold true against the what professionals are actually using? Clearly not, he is off and off by quite some distance, up to two digits (10lbs+). Lets keep the low tension recommendations for backyard badminton players and utter beginners; it is simply not helpful offensive, and borderline trolling those of us who are trying to improve our games, be more competitive in matches, and most importantly to avoid handicapping our opponents with ill advice to the point of devaluing match victories. I personally do not feel comfortable with accepting a win, or a close draw, knowing that my opponent was handicapped, nor do I wish to continue.


    As for the million dollar question of why there are those among us who prefer celebrity endorsement based "facts" and heresay rumors over actual evidence published by academics and insist on burying their heads in the sands, it is well and truely beyond me.
     
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  4. ucantseeme

    ucantseeme Regular Member

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    IMO as long as you can clear with your backhand out and don't suffer with pain, I think everybody should use what he/she is comfortable with, regardless which level, if he /she has a good technique. I agree that people with bad technique should use a lower tension and people with great to excellent technique can use higher tension, but everbody has it's own definition of low and high.

    IMO the choice of the racket is also an important attribute. As a stringer I receive a huge amount of stiff and x-stiff rackets which are head heavy. Mainly ZFII and mostly, I wonder how these guys made their choice. That these people who choose a sooooo demanding racket, which is more harm than good for them, can't take anything higher than BG65 at 22lbs is no wonder.

    Also I often see that most people tend to use thicker grips which can't allow them to use finger power. That these people suffer from power and can't use the full spectrum of a stroke, don't make me wonder that they can't use anything higher than BG65 at 22lbs.

    IMO it also depends which string you choose. When you choose something pretty thick with bad repulsion, you won't get power.

    TBH Normally people go to a stringer for years and tend to increase 1-2lbs on the next job. That these people will notice when they suffer and loose power is obvious and 1-2lbs too hard for their liking don't do harm for long. The difference is too small. I never came across a guy who came with his BG3 Factory String @ 16lbs and asked for BG80 at 30lbs.

    My opinion: Use what you feels comfortable, be focused on yourself instead of too much on things which others like.

    BTW regardless which tension, a job which is too long in the racket can also do more harm than good an can produce injuries. That the low tension guys, play a racket 4-6 month is normal. The repulsion of most strings lasts 2-3 weeks and die.

    Conclusion: Too thick grips, bad racket choices, using an intact string for too long can also do more harm than good. That high tension is the culprit is IMO not fair. We all came across guys with tennis elbows, who don't use high tension and they had many other reason for it. IMO it's impossible to set something in stone. I agree that beginners should use low tension...the rest depends.
     
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  5. visor

    visor Regular Member

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    Higher tension gives better crispier feel for accurate touch shots, whereas lower tensions give better power.

    So it's up to you what you like out of your strings.

    It has been said before, play with the lowest tension that still feels good and accurate for you, or play with the highest tension that you can still smash and clear effectively.

    Sent from my SM-G930W8 using Tapatalk
     
    #525 visor, May 2, 2017
    Last edited: May 2, 2017
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  6. dave010

    dave010 Regular Member

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    What would be considered a thick string with bad repulsion? I don't feel that repulsion really affects the power. For example, BG66UM doesn't hit nearly as hard as BG65 for me, even when it is new. Thin strings are said to have better repulsion but the power is not as good in my experience.
     
  7. visor

    visor Regular Member

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    Do about 10 mins of fast drives with thin vs thick strings and you'll understand the difference in repulsion.

    Sent from my SM-G930W8 using Tapatalk
     
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  8. dave010

    dave010 Regular Member

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    Haha, I must be awfully insensitive to the differences in repulsion then. My solution is just "Hit Harder!".
     
  9. visor

    visor Regular Member

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    A 0.65mm string compared to a 0.70mm one will feel crisper and get faster shuttle on and then off the stringbed repulsion. The bird will leave the stringbed a bit sooner and faster, instead of sinking in a bit more...which is where you feel it more in fast drive battles.

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  10. dave010

    dave010 Regular Member

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    Hmm... drives have always been one of my better shots, so I may have completely overlooked this one. That being said, BG65 at the tensions I use it at (30+) doesn't really feel sluggish IMO. I was always confused by all the talk about repulsion, especially when I was losing power with more repulsive strings.
     
  11. visor

    visor Regular Member

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    I use Gosen GT5 (0.65mm) at 28 lbs. Perhaps next time you restring your racket give that or LiNing #1 a try and see how you like the feel and difference. Could be an eye opener.

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  12. dave010

    dave010 Regular Member

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    LN 1 is on my N99 right now at 28lbs. :D I must be blind or something.
     
  13. visor

    visor Regular Member

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    Or not...

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  14. fanfaron

    fanfaron Regular Member

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    Just wondering how this is possible. If you are able to clear the shuttle at 30 lbs, then you certainly can at 22lbs. It`s not like 22lbs is a shoelace tension and shuttle get stuck on frame bed right. You write a long text most make sense but this is annoying to read. And I'm trying hard to stay polite... Your badminton level is certainly higher than mine, no doubt. But just doesn't make sense...
     
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  15. pepe54

    pepe54 Regular Member

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    (TLDR version - read the bold points)

    Well truth be told, I don't think that your badminton level is less, nor should we be comparing levels without having actually played each other IRL. I have heard recent mention of my badminton level improving vastly but I do still consider myself an amateur-beginner as I have been completely obliterated by players focusing on very specific styles. One of the horrible flashbacks involves a certain opponent who is able to read my entire game while others simply analyze my weaknesses in an instant and place the shuttle around like a routine. I would go as far as saying that I sometimes feel bad whenever going up against beginners or those with equipment handicaps knowing that my racquet - string tension - string choice setup boasts optimal and effortless repulsion qualities for me.

    Regarding the issue of why I failed miserably at using an identical ZF2 running 22lbs and a thinner string at that, it is indeed a baffling issue but perhaps this can be explained in terms of maximizing force transferrence and impulse by matching racquet stiffness with string tensions, ie, you do not want to pair an extra stiff ZF2 with a mickey mouse string tension setup. Others here have stressed on the importance of carefully matching racquet stiffness against string tensions:

    Adding further to @sautom88 's point, overall stiffness is the combined interaction between your string tension, head frame, shaft, and if you wish to be extremely detailed, grommet designs and overgrip material do matter too. There is little point in having an ultra stiff sub component at one end and have it undermined completely by a flexible material at the other end.

    What happens when you use a an overly flexible stringbed / racquet ?
    After striking a shuttlecock, it is not desirable for either to be in the backward flexing phase once the shuttle has left the stringbed for obvious reasons of dampening that force. Whenever matters of energy or force is involved, stiffness relates to direct transference of force. Real world application examples include: anti sway bars in vehicles which eliminate body roll ; rollcages, riveting and spot welding to eliminate chassis flex, etc. To maximise force transference, you want an optimal amount of stiffness.

    Next, up is impulse (aka acceleration force) generation. To have the shuttle travel at maximum velocity, you want maximum force being exerted on the shuttle over a minimum amount of time. This is exactly why we are told to make swift and short strokes to generate power whilst avoiding long duration strokes tend to disperse that power. Real world examples include airbags, hans devices, why skateboarders and pakour incorporates the idea of "rolling" into hard falls, etc.

    As a final thought, it is interesting to point out that I have been heavily criticized by some to have a very crude, "tennis like" style of swinging my entire arm and shoulder around instead of the more efficient and conventional wrist / isolated forearm flicks. Ironically, I have never played tennis in my life.

    I will also point out that my wrists are as flexible as a bunch of fused joints; they are quite useless and lack the range of motion needed for some of these conventional wrist / isolated forearm flicks. The research whitepaper does point out that the expert players are able to achieve the same shuttle speed by compensating for lower tensions through more wrist flexion at the end of their hitting stroke.

    I hope that sharing my experiences helps you arrive at an answer.
     
  16. pepe54

    pepe54 Regular Member

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    PS: It is also odd to me as to why other club members are unable to generate power whenever we swap racquets around; I suspect it to be related to reasons of stroke style (long vs short) and the wrist vs whole arm swing observations above. What I noticed here is the emergence of a tension threshold ; 28lbs racquets go in their favor while 31lbs tips towards my comfortable zone.

    Another issue baffling me at the moment is why I seem to generate less force with thinner strings. See http://badmintoncentral.com/forums/...review-owner-perspective.171056/#post-2549822
     
  17. ucantseeme

    ucantseeme Regular Member

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    I agree with @fanfaron. If you can clear with a stiff racket and high tension because of the right technique, you should be able to do this with anything. I'm not proud to say it: But I also managed to hit a backhand clear with an old and crappy factory strung racket and I was drunk as hell. That the shot didn't sound crisp and proppeled with not much speed is a different story, but that lower tension makes a clear to a midcourt drop sounds very drastic. I didn't experienced that. It doesn't make fun too play with much lower tension compared to a tension area which feels comfortable and familiar, but that a clear don't reach the baseline because of too low tension, sounds to me unbelieveable. I agree that drives aren't fast, that smashs are spongy and weaker and the control goes down All fast shots, will suffer, if you are using a non-familiar tension, but clearing end to end? Serious?
     
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  18. pepe54

    pepe54 Regular Member

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    Kudos to everyone able to hit backhand clears with $10 walmart / kmart racquets :)

    Full disclosure: I am actually a small short guy (5"5) with sticks for arms and short arms at that ; no tree trunk arms here. Perhaps I'm just plain weak and I lack raw force / power. Give me a $10 walmart racquet and chances are I will end up enraged at myself and disgusted from all the weak hits.

    I have tried in earnest to generate proper force with my old 24lbs (22, once tension loss is factored in) flexible racquet but nothing spectacular happened and I ended up with elbow tendinits instead from all that intense, but futile trying. I'd like to convince myself that the shuttles they use at my local club are generally considered slow/heavy but I would be lying to myself (rather, there is a trend here for other clubs to use faster / lighter shuttles to compensate for a wider array of skill levels). Results only really showed up when I switched to a head heavy, extra stiff racquet and 31lbs + tensions. I still struggle with 28lbs. There are days I wish that I was built like Fu Hai Feng but oh well thats life lol :D

    I remember @visor, @Gollum and @MSeeley quoting me the concept of "proximal distance to transfer" while coaching me on the concept of backhand clears, then I hear that being echoed around by the likes of Jan Jorgensen and Chen Long. Ironically JJ and CL do not seem to realize the advantages of having longer arms and instead say things like "you don't actually need a lot of force, just a long arm" so when the scenario is flipped, all theory goes out of the window and more force is necessary to compensate.
     
    #538 pepe54, May 5, 2017
    Last edited: May 5, 2017
  19. ucantseeme

    ucantseeme Regular Member

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    77 grains are less weight than 79 grains, while shuttles with 77 on the tube are slower the one with 79. So slower shuttles are also lighter and heavier shuttles are faster. :)
     
  20. pepe54

    pepe54 Regular Member

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    The shuttles we use are Aeroplane EG1130 (black label) speed 76 if I recall. Apologies for the mistake, by heavier I meant that they drag a lot through the air and suffer a significant slowdown past the half distance point. I do recall being able to hit backhand clears with the faster / lighter shuttles well before I developed the proper technique but I thought nothing of it at the time.

    Nowadays I do actually prefer these Aerogplane EG1130's over other shuttles as they not only feel solid upon impact but have a trifecta of durability, flight pattern consistency and slowdown characteristics. Most other shuttles speed up when worn ; these EG1130's slowdown further :D!

    You are right in saying that by strict weight definition that they are lighter however but 4.9g and 5.1g thats the range iirc
     

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