string tension, main/cross ratio, feel, etc...

Discussion in 'Badminton Stringing Techniques & Tools' started by kwun, Dec 17, 2009.

  1. kwun

    kwun Administrator

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    i cannot quite make sense of this. but here it is:

    i have two main rackets that i use most of the time. a ARC10 and a 2/3rd gen AT700.

    when i first bought it from MK, i asked them to be strung at "24lbs". which later on was confirmed to be 23M/25C. the string job is 4 knots.

    both rackets after the initial string job felt good. lively and powerful.

    after the strings broke in both, and after i got my WASE, i restrung at the same tension, 23M/25C, 4 knots. i even kept the same pattern. the result feels different, the racket seems dull and not repulsive. it took much more effort in comparison to get the same bounce.

    so recently, i restring them again.

    this time i decided to do some experiments.

    using the same exact pattern and technique, i did:

    ARC10: 25M/25C
    AT700: 25M/27.5C

    the AT700 feels more lively than my previous string job. the repulsion and power is back. i didn't think that an 10% increase in tension would make that much of a difference. the only other difference i can tell is that the C/M ratio is slight higher. C is exactly 10% tighter than M. while previously it was less than 10%.

    the ARC10 is even more odd. it feels way more lively than before and power was also excellent. the most strange part is that after a hour or two at the gym, the tone of the racket suddenly changed. there is a distinctive "PAK" sound when i try to hit the shuttle hard. it was strange and sudden change. i went and checked that the racket and string are both fine, nothing cracked or shifted.

    the testing were done in two separate days so there is less likelihood that i just happen to feel good that way. i will continue to use them and see.

    but meanwhile, anyone can come up with an explanation? i wish i have more AT700/ARC10 so i can do more tension and M/C ratio experiment. but unfortunately i don't.

    and i am sure some of you remember my previous inquiries on what makes a string job better, most of the recommendation came back as consistency and doing little checks here and there. well this time i didn't do anything different with how i strung the rackets.
     
  2. silentheart

    silentheart Regular Member

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    1) Is MK=HK? If I remember it right?
    2) Do you know what machine the shop use? The reason I am asking is mounting and tensioning head might make a difference.
    3) Which pre-stretch method does the shop use (or the shop is not pre-stretching?)? The reason I am asking is may be 10% pre-stretching might be too high for badminton?
    4) Do you have a diablo drum on your tensioning head? That make a wold of difference.
    5) On the crosses, do you clamp right after the tension is reached and remove the stringer from the gripper? Or you keep it on the gripper and weave the next cross then clamp? Try to a experiment on this. If you do the later, pre-stretch might be needed.

    I have think of everything I can. Good luck.
     
  3. dunmaster

    dunmaster Regular Member

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    for your AT700, you meant 25M / 27.5C, not 25C / 27.5M, correct?

    also, are you using the same string as MK did?

    if everything the same, the string, even the color of the string, the age of the string, the pattern, etc., there are two causes:

    1. the pre-stretching of the string and the speed of stringing, or in general, how it's done (you did it on your machine, vs MK did it on their machine).

    2. you do need to use higher tension as you are improving over time!

    would like to find out the reason as well, since I have found this "optimal" tension is very dependent upon string, stringer, string pattern, and even racket.
     
  4. taneepak

    taneepak Regular Member

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    Both these two racquets use very stiff materials (different from shaft stiffness) and as a result their frames have very high Youngs modulus. This is ideal for high tension as unlike racquets with lower Youngs modulus material, which will "flex" more readily with power shots, the ARC10 and AT700 will have more effortless "punch" because they will "flex" less. Frames that "flex" less lose less energy when hitting power shots, more pronounced at higher tension.
     
  5. silentheart

    silentheart Regular Member

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    1) I am sorry, what are you smoking? Or are you too drunk to understand what Kwun was asking?
    2) Can you please enlighten us why Kwun is experiencing the racquet plays better with 25x25lb on ARC10 and 27.5x25lb on AT700? I do no have a solid answer to that, so I did not attempt on that area.
     
  6. singnflip4life

    singnflip4life Regular Member

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    I think what taneepak is saying, is that the lively, more springy feel comes from the properties of the materials from the racket head, which perform better at higher tensions due to their Young's modulus. So since Kwun strung at a higher tension, this brings the point into play. Just how much of what he said is credible, I can't say.
     
  7. kwun

    kwun Administrator

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    sorry for the typo, yes, AT was strung at 25M/27.5C. i have corrected it in the original post.

    the machine used by MK was a exthree electronic, similar to Pete's. i don't know if they turned on pre-stretch or not.

    i have tried on my WASE both pre-stretch and no pre-stretch. not much diff.

    so to summarize:

    MK - Exthree - 23M/25C - lively, good power
    Kwun - WASE - 23M/25C - pre-stretch - dull
    Kwun - WASE - 23M/25C - no pre-stretch - dull
    Kwun - WASE - 25M/25C - no pre-stretch - lively
    Kwun - WASE - 25M/27.5C - no pre-stretch - lively

    the first 3 data points should nullify taneepak's claim of higher tension, as they are done in the same tension and have different feel.
     
  8. kwun

    kwun Administrator

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    a proper experiment to do will be to gather a couple dozen rackets of the same exact model, and then string them (by the same stringer) with various tension and M/C ratio combinations. then give them to badminton players and have them rank the playability of the rackets. they shouldnt know which racket is what tension.

    then after that, we come back and analyze what combination provides better feel.

    this unfortunately will be rather unfeasible given the number of rackets needed and the scale of the whole experiment.
     
  9. silentheart

    silentheart Regular Member

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    Does it have to be the AT700 or ARC10? What if we can get you some mid range racquets (AT30? That is cheapest YY i can find that comes unstrung) for your fun experiment?
     
  10. kwun

    kwun Administrator

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    wow. thanks for the offer.

    in theory the racket model shouldn't make much difference given that the tension range for testing is suitable for it.

    how many can you get?
     
  11. silentheart

    silentheart Regular Member

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    Let's take this off line.
     
  12. cooler

    cooler Regular Member

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    i think most of u have hit the main points, it now come down to a process of elimination. One thing missing is which kind of string used (a secret??:D:D)Since both kwun and MK use electronic machine, it could be due to difference in calibration. We don't know if the is 25 lbs reading is the same 25 lbs on kwun's machne. In commercial stringing, the machine is used alot and we dont know how often their stringer calibrate the machine. One day of usage may equal to 2 years kwun machine usage:D Secondly, age of string does degrade string elasticity.
     
    #12 cooler, Dec 17, 2009
    Last edited: Dec 17, 2009
  13. cooler

    cooler Regular Member

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    i equate taneepak's theory to global warming debate.
    i think the feel difference is mainly due to the stringing difference (tension and/or string material), like in climatic changes we should focus what's happening to the sun. Taneepak think the feel difference is related to the racket material, like saying the global warming is due to the CO2 concentration.
     
    #13 cooler, Dec 17, 2009
    Last edited: Dec 17, 2009
  14. kwun

    kwun Administrator

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    oh. and more clarifications. :)

    the string used are identical. BG80. both of which are new strings. if you want to know the source, i bought mine from MK also. so no claim of fake strings. and i bought them the same time as i had the racket first strung so may even be of similar batch.

    the tone coming out of the rackets are to my ears identical (which implies tension is very similar). given that yes, i was comparing the tone on a AT700 to a ARC10. but i believe they are of close enough shape and size to be close.
     
  15. kwun

    kwun Administrator

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    as for string age. the strings used by MK and me are from the same time (April 2009) as mentioned by previous post.

    the time line of stringing was:

    April 2009 - good
    June 2009 - bad
    Sept 2009 - bad
    Dec 2009 - good

    the data don't support the string age theory.

    the only variation i can tell is:

    - variations in method of stringing
    - string tension / M/C ratio

    and anything else you guys might come up with.
     
  16. cooler

    cooler Regular Member

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    ok, u have cleared up on the string age thingy:D Ya, possible things left are difference in tension gauge readings and technique employed while stringing.
     
  17. silentheart

    silentheart Regular Member

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    May I throw in another theory? Kwun, if you wish to give it a try, I will send you a pack of string for your trouble. 1) For M/C ratio, I use cross as my final tension. Then I take 0.9xcross as my main. 2) I only pre-weave the mains. For crosses, tension 1 cross->release clamp->weave next cross->clamp the cross->tension next cross. Repeat the process. 3) Center out for cross. 4) Get Diablo drum if you don't have one. It prevent the string shock. If not, tension the string slowly.
     
  18. cooler

    cooler Regular Member

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    may i add another theory too?:D after tensioning, how firm the clamp hold the tensioned string also make a difference cumulatively. Do u use 1 or 2 flying clamps to hold each string? It maybe MK uses fix clamps. Fix versus 1 flying clamp do make difference when u r getting to the 25 lbs range
     
  19. kwun

    kwun Administrator

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    One more data point. I feel that the arc10 with 25/25 feels better than the at700 with 25/27.5. But then that could be due to different racket. which is why doing a proper experiment requires identical rackets.
     
  20. kwun

    kwun Administrator

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    1) yes, that how I'd specify tension if I were to give only one number. However that does not explain why 25/25 feels the best among all my trials so far. Something else might be different.

    2) I use double clamp. I clamp the current string and the previous string, alternating between two clamps.

    3) have not tried center out cross

    4) I have a diablo. But it won't fit. If you take a look at the photo of my wase. There isn't enough room to fit the diablo in.
     

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