I have the power of ESP. I can see the future of tennis strings.

Discussion in 'Strings' started by travlerajm, Jun 30, 2013.

  1. travlerajm

    travlerajm Hall of Fame

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    ESP stands for Extraordinary Spin Potential.

    I strung up my Blade (my regular stick) with kevlar/ZX at 63/49 (both pre-stretched manually).

    Combining:
    a) large difference in stiffness between mains and crosses
    b) with a 14-lb differential in tension
    c) on a low-friction setup...

    ...yielded a result that was nothing short of amazing.

    The stringbed was firm and crisp with perfect directional control and depth control on volleys and flat shots. But the mains are free to travel laterally and snapback better than in any setup I've used previously.

    When I wanted to spin the ball heavy on serves or forehands (or outside-in bh slices), the spin was as heavy and extreme as the spinniest shaped poly. But it does not have the high launch angle of other spin-friendly setups. And when I wanted something in between flat and heavy spin (like a finesse topspin lob to the backhand corner), I got the trajectory I wanted there too.

    The "dynamic range" of the stringbed is something I've never come close to with any conventional setup.

    I chewed the fuzz off two balls (the only downside I've noticed) hitting against the wall for an hour (where I added a couple grams to the tip to make up for the lost SW of the 1/16" shorter hoop), then played a couple hours of doubles outside. Really enjoyed being able to use my complete game by having a such a versatile stringbed. Serves were great too.

    My ESP sees kevlar making a comeback soon, with more people going to extreme tension differential between mains and crosses.

    One interesting thing that is noticeable, comparing a full poly stringbed to this one:

    When I pull a main string laterally on the full poly bed, the (positive) resistance force when stretching is much greater than the (negative) resistance when allowing the string to return. In otherwords, much of the snapback force in the full poly stringbed is offset by the friction between the strings. In the high stiffness ratio, high tension differention stringbed, the snapback force has minimal friction resisting it.
     
    Last edited: Jul 7, 2013
    #1
  2. fortun8son

    fortun8son Hall of Fame

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    Aww, man! You know what they do to people who really can tell the future?
     
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  3. Bhairava

    Bhairava Rookie

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    wow! wonderful results, if they are not some sort of placebo effect :p
    the main problem is that 28kg/22kg is something that would destroy any racket in the long run, if not specifically made for those particular tensions.
    What happens if you make just 7lbs as differential instead of 14lbs?
     
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  4. Bhairava

    Bhairava Rookie

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    Well, another point to be raised:
    what about using poly instead of kevlar at your same tensions? I can suppose a rough, textured, shaped poly instead of the kevlar will make the trick even more extreme ;)
     
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  5. newyorkstadium

    newyorkstadium Semi-Pro

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    deleted...
     
    Last edited: Jul 8, 2013
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  6. FlyingAce

    FlyingAce New User

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    Poly loose tension very fast, no matter what you do, where kevlar have a "plateau" zone after some time, so if we prestretchit should hold tension much better that poly.

    As for using gut instead of nylon, there some idea of beeing string vegetarian. In theory it should work.
     
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  7. Bhairava

    Bhairava Rookie

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    Sure it lose tension very fast, but it performs very well in those few hours. As wilson steam 99s enhance main string movements via less crosses, and it's best string is luxilon 4g 1.41, I could imagine how 4G/ZX could provide even more spin than kevlar/ZX. The point of using kevlar is for having long lasting stringbed, but if we speak about extreme spin potential a 4G 1.41 for some hours or tour bite 1.30 for even less hours could provide even better spin.
     
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  8. travlerajm

    travlerajm Hall of Fame

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    The point of kevlar mains vs poly is twofold:

    1. It is 3x stiffer than poly. This permits a stringbed with high enough stiffness for excellent control even when the crosses are strung at very low tension.

    2. It holds tension much better than poly (after it is either pre-stretched or broken-in).

    I believe kevlar mains are key to the success of this setup.

    As for other materials in crosses, I tried 15L nylon already. The results were similar to the ZX (really nice), but only for the first 1-2 hrs of play. After that, the stringbed transformed from a low-friction stringbed to a locked stringbed and played similar to conventionally string kevlar/nylon after that. Monogut ZX will not lock like nylon (unless strung very tight). Poly crosses might work ok, but since they don't hold tension nearly as well as pre-stretched Monogut ZX, the stiffness of the stringbed would soften faster over time.

    I've played with kevlar/poly hybrids almost exclusively for the past 5-6 years. Once the stringbed gets soft (because the poly loses a lot of tension), the setup becomes extremely spinny, but the launch angle is high so directional control suffers and volleys and flat shots are not very precise.

    The point of this thread is that I am getting the dual benefits of a stiff stringbed (excellent directional precision) and a soft low-friction stringbed (extreme spin potential) at the same time. In my experience, that is not possible with a conventional string setup. Before, I either had to choose one or the other or compromise with something in between. Now I don't have to choose anymore.
     
    Last edited: Jul 1, 2013
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  9. Bhairava

    Bhairava Rookie

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    For point 1. - I think a stiff poly like 4G 1.41 at 28kg(63lbs) would be VERY STIFF too. solinco tour bite 1.30 too. And if they wouldn't, you could just raise 3 lbs for main and 3 lbs for crosses, getting same stiffness and same differential tensions.
    For point 2. -luxilon 4G has very good tension maintenance. Beside of this string kevlar retain tension better for sure, but it hasn't the spin capability of shaped poly ;) however kevlar/ZX seems to be the better combination of spin and durability if this absurd setup will be confirmed and tested more :)

    But really don't you feel super stiffness with kevlar mains at 63?It isn't breaking your arm?(beside of breaking your racquet :p )
     
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  10. travlerajm

    travlerajm Hall of Fame

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    Again, a very stiff poly is still less than half the stiffness of kevlar. And no, the kevlar at 63 lbs on the Blade doesn't feel that stiff because it's crossed with ZX monogut at 49 lbs, which is quite soft.

    The whole point of my setup is that it is fairly stiff in the normal direction, but very free to allow movement in the lateral direction. A stringbed with these two properties gives you ESP.
     
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  11. Bhairava

    Bhairava Rookie

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    I'm spreading your experiment over italian tennis forum ;) maybe a friend of mine will try this combo. I'll try too if I find a cheapy racquet to work on, I don't want to risk pro stock six.one ;)
    The point is: why no one has ever tried setups like that?I can imagine company like luxilon, babolat,prince etc have much more possibilities to try every combination...they could even produce a racquet made for working with 15lbs as differential.
    By the way, tell us how many hours this setup will retain it's spin capability ;) it would be wonderful to find an instrument to measure spin too...
     
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  12. JT_2eighty

    JT_2eighty Hall of Fame

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    Very interesting, I'll have to revisit my kevlar trials, although I traded all my kevlar away as I focused solely on gut/poly for the most part as of late--which for me, also has excellent directional precision, and soft low-friction string on string interaction for great spin (perhaps not extreme spin). How do you compare gut/poly to this current setup? Which Blade do you use?

    Keep it up, always enjoy your threads! Kevlar/poly has been the craziest spin setup I've ever tried, but the directional control over time was mediocre. This 63/49 kev/zx setup has potential... but I'm using a frame that is out of print and worried also about the 14lb differential, as it is very flexy and I've tried large differentials before and had serious warping that I had to cut out the strings before damaging the hoop. Sounds like this one needs a stiffer frame to hold up to the rigor, I've a couple YTPP with 66 flex that I've strung at 60/40 and the warping was barely measurable.
     
    Last edited: Jul 2, 2013
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  13. travlerajm

    travlerajm Hall of Fame

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    I have the Pink BLX Blade 98. I am not using the outer mains (using 16x20 instead of 18x20).

    When I used kevlar/poly strung with no tension differential (for most of the last 5-6 years), I had the same observation as you: the directional control deterioriated over time as the poly dropped tension and the stringbed softened. I also noticed that the frame would squash over time. Typically, a round frame like my Warrior OS would be 1mm squashed (1mm shorter than relaxed length) when freshly strung. Then it would gain back 0.5mm in length as the kevlar breaks in. But after the break-in, it would start to go in the other direction and squash, eventually settling at about 1.5mm shorter than the relaxed length (because the poly has an asymptotic tension plateau about 10-12 lbs lower than the kevlar).

    With kevlar/ZX, when both are pre-stretched and used with no tension differential, the racquet stays the same length after stringing (about 0.5mm shorter than relaxed length). It doesn't change length over time because the kevlar and Zx have similar tension relaxation profiles, except near the end of the kevlar's life when it starts to notch more than halfway through (at which point the racquet gains length rapidly).

    With the kevlar/poly, I needed to re-tune the SW frequently (to get my MgR/I tuned to my favored 21.0 by adding or substracting up to a gram of lead tape at the tip. Before I became aware of this inherent SW instability from the kevlar/poly tension stability mismatch, I lost matches because I'd show up at the match thinking my frame was tuned, and then struggle because the SW had shifted.


    With the current 14-lb differential, the Blade was at -2.3mm length when freshly strung, then gained back almost 1mm after the break-in. Length seems to be holding steady at -1.5mm so far, which means the actual tension differential is no more than with kevlar/poly strung with no differential at the end of its life.
     
    Last edited: Jul 2, 2013
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  14. newyorkstadium

    newyorkstadium Semi-Pro

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    How long are you hoping this stringbed will last? You got 30 hrs out of your last setup.

    Most people on here think gut/poly is better then poly/gut. I wonder if poly/gut is better if you add in a large tension differential.

    I don't think it can be ruled out that people with lighter rackets will feel pain from a 63 lbs kevlar main. You have a heavy racket, with a high SW.

    How much does a -1.5mm length alter the racket's balance and specs, like SW? I've never readjusted racket specs to account for tension loss.

    Thanks
     
    Last edited: Jul 8, 2013
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  15. Power Player

    Power Player G.O.A.T.

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    Kevlar at 63#s?

    No thanks.
     
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  16. purple-n-gold

    purple-n-gold Professional

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    Dang it traveler, I'm all out of kevlar:) kev/poly was my hybrid of choice last year and had some good results, def gonna try this,, anywho been wanting to try this MonoZx stuff out. Always enjoy your threads btw!
     
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  17. travlerajm

    travlerajm Hall of Fame

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    The experiment is in progress... time will tell...
    I think one of the reasons that gut/poly is preferred by many is that it naturally has a large tension differential. The mains are already 5+ lbs more than the crosses, and the when you add the extra ~10-lb loss of tension in the poly vs gut, you end up with close to 15 lbs tension differentional when you string gut/poly at the same reference tension.

    I have no desire to try poly/gut at any tension differential.

    If you are worried, you could always try at a lower tension then.

    A 1mm length change due to hoop deformation makes up to 2 kg-cm^2 difference in SW. Most people wouldn't notice. But if you tune MgR/I like I do, it's very noticeable. My forehand is pretty darn good (4.5-5.0 level) when my MgR/I = 21.0, but I spray the ball a lot more (fh drops to 4.0-4.5 level) if MgR/I drops to 20.95.
    I haven't tried those polys. I still have lots of poly in my drawer at home (a half-reel of Silverstring, a half-reel of PTP, a few packs of SPPP). I might continue to use these for experiments, but I don't think I'll be buying anymore poly anytime soon. In my opinion, the advent of Monogut ZX removes most reasons to use poly.

    As a cross, the ZX is all-around better than poly in just about every way. The main difference is of course tension maintenance (which is a big deal for me - I really dislike stringbeds that change over time). But ZX also outperforms poly in power level on the serve. It seems like it has better energy return for a given stiffness level.

    I may try kevlar/poly at high tension differential to see how it compares to kevlar/ZX, just because I'm curious.
     
    #17
  18. FlyingAce

    FlyingAce New User

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    Travlerajm, could you please elaborate on what makes ZX so special in comparison with poly as a cross.

    Thank you
     
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  19. NLBwell

    NLBwell Legend

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    Travlerajm, thanks for posting this info. I might try this setup. I used Kevlar/syngut most of my playing life, and really enjoy Kevlar/gut. I got a ton of spin with Kevlar/poly, but it hurt my wrist. Also, it was strange the way it felt that the strings were sliding around. The softness of the ZX (and lower price than gut) might make this a very good setup for me.
     
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  20. ricardo

    ricardo Professional

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    Tension differential VS Stiffness differential..

    Tension differential VS Stiffness differential..please explain...

    If you string Natural gut (Pacific Classic 16g) at 51lbs reference tension, the stiffness is 100 lbs.

    If you string poly (Babolat Revenge 16g) at the same tension, the stiffness is 304 lbs.

    51lbs reference tension:
    Natural gut stiffness = 100 lbs
    Poly stiffness = 304 lbs.

    source:
    http://twu.tennis-warehouse.com/learning_center/reporter.php

    thanks in advance...
     
    #20
  21. travlerajm

    travlerajm Hall of Fame

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    I think normal/lateral stiffness ratio is what matters. I believe it affects spin both by enhancing asymmetric stretch and by enhancing energy return from sliding-main snapback.

    Assuming that the stringbed can be modeling as springs in parallel:
    For gut/poly, this stiffness ratio is about (100 + 250) / 250 = 1.4.
    For poly/gut, stiffness ratio = (250 + 100) / 100 = 3.5.
    For kevlar/poly ratio = (600 + 250) / 250 = 3.5
    For kevlar/ZX, stiffness ratio is about (600 + 150) / 150 = 5.

    I would expect these numbers above probably roughly correlate with the relative spin contribution from asymmetric stretching, but they don't tell much about snapback. The snapback contribution (which is, in my experience, roughly equally important as the asymmetric stretch contribution) would be difficult to model with a simple equation, because it has to take into account interstring friction as well as the goldilocks principle (there appears to be an optimum for the degree of string-sliding freedom).

    For example, gut/poly has a much lower stiffness ratio than poly/gut. But the lower stiffness ratio is more than offset by a much lower interstring coefficient of friction, so its spin potential can be greater than poly/gut if the tension is right.

    The spinniest setups, in my experience, are the ones that take advantage of both high stiffness ratio and optimized interstring sliding/snapback.

    Using a large tension differential enhances both the stiffness ratio and the snapback efficiency.

    I hit again for 1.5h of baseline games against my regular hard-hitting 5.0 partner. The stringbed performance yesterday was transcendent. I could do whatever I wanted with the ball. For flat shots, the stringbed feels locked. But when I take a big cut, I can really feel the lateral deflection of the mains, and the result is terrific spin that made it easy to keep the ball in the court. Normally, I am the more defensive/reactionary player of the 2 of us, but yesterday, I was the one dictating play. I don't think I'll ever string without high tension differential again - yes, it makes that much difference. There's no going back.
     
    Last edited: Jul 3, 2013
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  22. travlerajm

    travlerajm Hall of Fame

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    For one, there is no comparison when it comes to tension maintenance. I can get 2-5 hours of quality performance out of a poly when used as a cross with kevlar. The poly gets softer and softer - it never really stabilizes.

    But I am getting about 30 hours with kevlar/ZX, and the only reason I don't get more is because the 18g kevlar eventually gets sawed through. I could probably get 60 hours if I went with 16g kevlar instead of 18g.

    Second, poly has very low energy return at high swingspeeds. This makes it less than ideal for serving. Monogut ZX is the opposite. It has really good energy return at high swingspeeds, which makes it nice and powerful and spin-friendly on serves.
     
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  23. newyorkstadium

    newyorkstadium Semi-Pro

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    I will add this to my playtest list. Would it be okay to have a stringer pre-stretch the strings, or must it be done manually? Would the string-bed still perform superbly if the strings weren't pre-stretched?

    So a stringbed can have too much string-sliding, causing a decrease in spin? Can you estimate at what COF this change occurs?
     
    Last edited: Jul 8, 2013
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  24. travlerajm

    travlerajm Hall of Fame

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    It would still probably have much of the same effect, but their would be two problems:
    1. The stringbed softness would not be very consistent over time, since ZX stretches a lot if not pre-stretched fully.
    2. The shape of the racquet would not be consistent over time, which can throw off you timing as the SW changes.

    I did a manual stretch this time because I overloaded the steel-frame step-ladder of my pre-stretch device and crushed it under too much string tension (I should have taken the 250-lb/step specification more seriously).

    I stretched the Monogut ZX manually by looping one end over the end of my kitchen bar countertop and pulling an 18-ft piece of string by leaning with my body weight until it stopped extending plastically. The 18-ft segment was 19-ft (relaxed length) when I was done.

    To pre-stretch the kevlar, leaning with my body weight was not enough unless I was patient for it to creep (which doesn't happen fast with kevlar). So I stood on top of my dropweight stringer, set the weight to 85-lbs, and kept adjusting the ratchet. I was able to get about 2" of extra relaxed length in 15 minutes of ratcheting from a 19-ft piece of kevlar this way.
    It has less to do with COF and more to do with the tensions. If both the mains and crosses are too soft (too low tension), then the spin potential goes down. But it's hard to know if the reason for this is too much interstring sliding (as postulated by the Tennis Professor), or too little normal stiffness to take advantage of ball compression-associated overspin or tangentially directed snapback.
     
    Last edited: Jul 4, 2013
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  25. travlerajm

    travlerajm Hall of Fame

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    Kevlar/Poly at high tension differential

    To see how kevlar/poly would work at high tension differential, I strung up my Gamma T5 late last night.

    The T5 has unique specs: 74 RA stiffness, 100" headsize, 18x19 pattern, with center mains very dense. Unless strung very loose (low 40s) with low-friction stringbed, the racquet doesn't like to spin the ball.

    The frame already had 17g ashaway kevlar / 16g Prince Tournament Poly strung in low 40s, but the bed had already gotten too soft to perform well after hours or so of play, strung a year ago.

    I clamped it onto my stringer, cut out the poly crosses, snipped the outer mains, pulled tension to 55 lbs on the outer mains, walked off the friction slack until all mains were at 55 lbs, and tied off without outer mains (so just 16 densely spaced mains). Then I restrung the crosses with fresh 16g Prince Tournament Poly at 36 lbs.

    Since the kevlar was effectively pre-stretched (by being re-used), and the poly was not, this represents an even more extreme tension differential than the 19-lb difference in reference tensions. The racquet was 3/16" shorter after stringing compared to strung length before the re-stringing, so I would guess that it's about 1/4" shorter than relaxed length. The T5 has an elongated head shape, so now the rounder headshape is more PureDrive like.

    Will test it soon. Feels like nice stiffness ratio bouncing the ball in my living room.
     
    #25
  26. moonballs

    moonballs Hall of Fame

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    What is the definition of lateral stiffness? If it is a measure of the firmness when trying to slide the mains laterally against the crosses, shouldn't it be the stiffness of the mains?
     
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  27. newyorkstadium

    newyorkstadium Semi-Pro

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    Would my local stringer be able to pre-stretch the ZX and Kevlar? Or must this be done manually?

    Yet the low, low tensions thread speak of heightened spin. This seems to go against the science.

    I was re-reading your pre-stretched poly experiment. How many hours do you think a Kevlar/Poly, or Poly/ZX, would remain playable if the poly was pre-stretched? I think this thread has opened up an opportunity to try many hybrid combinations.

    Do you think all strings should be pre-stretched, gut and nylon included?
     
    Last edited: Jul 6, 2013
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  28. travlerajm

    travlerajm Hall of Fame

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    The 55/36 re-used kevlar/fresh poly on my T5 worked remarkably.

    The bed was slightly softer than on my Blade. Flat shots still controlled. Topspin forehands had borerline cartoonish spin.

    I let a few other guys at the park try my T5. They were dumbfounded that a racquet could have that much spin but still have that much control. I hadn't even tuned the weighting yet.

    Feels like a normal stringbed when you try to hit flat. But when you want to hit spin, it's anything but normal. Even when taking steep uppercuts, the launch angle stays low, so you don't need to close the face as much as you would with a conventional low-friction setup. This means the spin window is about double of with normal racquet, so no shanks, and huge cuts are rewarded as reliable heavy shots.
     
    Last edited: Jul 6, 2013
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  29. travlerajm

    travlerajm Hall of Fame

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    All strings including poly, will have the following properties after pre-stretching:

    1. Better tension maintenance.
    2. Higher effective tension for a given reference tension (feels tighter).
    3. Higher energy return for a given effective tension.
    4. More stable playing characteristics over time.

    If you prefer stringbeds that do not change in playing characteristics over time (like I do), then pre-stretching is a good idea. For poly string, which loses a lot of tension immediately after stringing if you don't pre-stretch, you might need to drop the reference tension from what you are used to so that the pre-stretched stringbed does not feel excessively tight.
     
    #29
  30. spinovic

    spinovic Hall of Fame

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    I am fascinated by this idea/experiment travlerajm. Nice work.

    I'd be curious to hear some other experiences with this when they try it.
     
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  31. ricardo

    ricardo Professional

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    How to pre-stretch a string.

    Can you pre-stretch a string by waiting 20-30 seconds before clamping.

    I have a Gamma Progression 200 (http://www.tennis-warehouse.com/Gamma_Progression_200_Stringing_Machine_/descpageGAMMA-GP200.html).

    It is a drop weight machine.

    I normally clamp the string as soon as I get the bar to horizontal or near horizontal. This usually take about 5-10 seconds.

    Should I wait 20-30 seconds before clamping to allow the string to stretch some more? Sometimes, if I wait 30 seconds for some reason, the bar goes down and I have to re-adjust. Should I intentionally wait for 30 seconds to 'pre-stretch' the string?
     
    #31
  32. travlerajm

    travlerajm Hall of Fame

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    One interesting thing that is noticeable, comparing a full poly stringbed to this one:

    When I pull a main string laterally on the full poly bed, the (positive) resistance force when stretching is much greater than the (negative) resistance when allowing the string to return. This "hysteresis" in the snapback does not seem to exist on the high stiffness ratio, high tension differential stringbed.

    In otherwords, much of the snapback force in the full poly stringbed is offset by the friction between the strings.

    In contrast, in the high stiffness ratio, high tension differention stringbed, the snapback force has minimal friction resisting it.
     
    #32
  33. BlueB

    BlueB Hall of Fame

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    I've been stringing hybrids with 10 lbs digferential for ovef a year now. Great spin. No problems with frames whatsoever. Many oppondnts say that mu balls have nasty sidespin component too.
     
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  34. souledge

    souledge Semi-Pro

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    Man this guy ignores every question on how to prestretch besides his prescribed way of prestretching.
     
    #34
  35. newyorkstadium

    newyorkstadium Semi-Pro

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    As ever, thanks for the detailed replies.

    Would it be okay to have a stringer pre-stretch the zx, kevlar or poly? Or must it be done manually?

    You have told me that spin potential go's down with too low tensions. Do you know why so many people experience heightened spin on the extra low tension thread?
     
    Last edited: Jul 8, 2013
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  36. travlerajm

    travlerajm Hall of Fame

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    There are many ways to pre-stretch.

    ZX is the easiest string to pre-stretch. It can be stretched easily with the "doorknob" method. I highly recommend prestretching the ZX, otherwise it is a pain to string (because it elongates so much under tension during stringing).

    Kevlar is harder to pre-stretch. Kevlar requires either very high tension (80+ lbs) or enough patience to allow it to creep.

    Poly takes time to creep, but too much tension can make it fragile, so pre-stretching poly is best done slowly under constant tension.

    All 3 of these types of strings will hold tension much better with pre-stretching.

    Extremely low tension (ELT) stringbeds have good spin because they allow a lot of lateral interstring sliding. But in my experience, ESP stringbeds (as I have defined in the OP) have even more spin potential than ELT. I believe it's because ESP stringbeds allow nearly as much lateral interstring sliding as ELT, plus the added spin-increasing effects of more ball compression and reduced snapback hysteresis.
     
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  37. allenkau

    allenkau Rookie

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    I love ELT. But the launch angle is starting to get to me. What happens if you only prestretch the ZX and not the kevlar (I am too lazy)?

    I read on the ZX thread that its performance is very sensitive to tension. How did you end up with the tension shown in your signature? How many trials did you had to try sir?
     
    #37
  38. travlerajm

    travlerajm Hall of Fame

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    Both ZX and kevlar have extremely large tension loss in the break-in period. If you pre-stretch the ZX, but not the kevlar, and then string with 15-lb tension differential, your frame will probably start out ~3/16" squashed. But after you hit with it for an hour or so, the kevlar will stretch out, and your racquet will likely return to its relaxed length. The remaining tension differential will probably only be ~2-3 lbs, and won't get the full benefit of ESP.
    Trial 1:
    My first try with kevlar 18/ZX Red 16 on my Blade was at 49 lbs (neither pre-stretched). First day felt ok for control and nice spin (and extremely powerful on serve). But second day rebound angle was to high to control the ball well (way too loose).

    Trial 2:
    I then restrung the frame by re-using the same string, but upped the tension to 55 lbs (the 2-3 hours in the frame at 49 lbs was effectively a light pre-stretch). I omitted outer mains (used only central 16x20). This time first day was boardy, not that spinny, but superb control. Over the next two sessions, the string bed softened a little, settling in with excellent spin, great control, nice pop on serve. I got about 24 hr before the tension had gradually dropped below my comfort zone, and decided to cut out. But this hybrid had officially become my string of choice.

    Trial 3:
    Bought a reel of ZX 16 Wheat. This time, I pre-stretched both the kevlar and the ZX on my pulley-&-weight device (both for an hour at 40 lbs, but with some bouncing to 60 lbs). I strung up my Blade at 56 lbs, 16x20 again. First couple of days were even boardier than with last test (felt several lbs tighter than previous test). Control was excellent, but spin was lacking - I was concerned that the Wheat was not allowing the mains to slide like the Red did. But after 4-6h of hitting, the stringbed "unlocked", and suddenly the spin was great, just like with the zone of excellent performance I observed with the kevlar/Red. I got about 30h of play out of it before I cut it out - at that point, the stringbed was still playing nice, but I noticed that the racquet had extended more than a mm because the 18g kevlar had been sawed 1/2 through, causing it to hold tension less well than the ZX. The slight bump in SW messed up my timing, which was fized by the addition of a gram of lead to the tip, but I cut it out after 30+ hours anyway, as I guessed that the kevlar would snap in 5-6 more hours. I was quite happy with my purchase - I was completely sold as a kevlar/ZX hybrid guy.

    Trial 4:
    I pre-stretched both the kevlar and ZX, but had to do it manually this time, (because I bent the frame of my steel step-ladder with an overly ambitious pre-stretch that exceeded the weight limit per step). Instead of 56 lbs for both (which I found was dialed in right, but only after allowing a 4-6h break-in), I upped the mains by 7 lbs and dropped the crosses by 7 lbs. This gave me 63/49. With this tension differential, the stringbed did not feel as boardy to begin because the mains and crosses were already unlocked and sliding and snapping back well from the first hit. Spin was significantly better than any conventionally strung frame, but rebound angle was remarkably low considering the spin potential. Stringbed felt like a regular firmly strung strungbed with good control on flat shots. I have about 10 hrs of play on it, and haven't noticed any change in performance since day 1. I may try upping the differential even more to 65/47 next time. I'm now an ESP guy and not going back.
     
    Last edited: Jul 9, 2013
    #38
  39. Bhairava

    Bhairava Rookie

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    We really need Simeone else with a stringing machine to try this experimental setup. And we need to Know what happens to the frame with 14lbs differenti al tension,especially on a very used frame.
     
    #39
  40. mykoh

    mykoh Rookie

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    trav, i'm a big fan of yours and i'll be trying this out in about a week's time when my supply of kevlar and zx get here. when i do i'll be sure to let the rest of you guys know how it plays. based on theory, and your raves, it does kinda make sense and i can't wait to try it out for myself.

    pre-stretching kevlar, now that's the challenge. i have a crank instead of a dropweight, would that work? just set it to pull max tension and turn the crank slowly. would i damage the machine that way? mess up the calibration?

    it was either that or the patience + body weight method.
     
    #40
  41. AR15

    AR15 Professional

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    This thread inspired me to try Kevlar for the first time.

    I've been using all poly or poly hybrids for years. I love the spin I get with it, and the power is adequate. I started playing with the Wilson Steam 99s this year, and I love the way poly plays with this racquet.

    So, since I've never had any elbow problems in the 11 years I've been playing tennis, I decided I'd give kevlar a try. I was hoping to see even more spin with it than I get with full poly and I expected to lose a little power. I strung my mains with Ashaway kevlar 17 at 50 lbs, and synthetic gut crosses at 55lbs. (I usually string my poly anywhere from 48 to 55 lbs, but 52 seems to be my sweet spot lately)

    My findings: I absolutely hated it, and will cut it out after I have only spent 30 minutes trying to hit with it. I got less spin, and zero power with this setup. The kevlar strings move all over the place and don't return like poly. And, my arm was getting sore immediately. I put my kevlar strung racket down and commenced hitting with my other racket with full poly, and all was right again.

    I know my experiment cant speak for everyone. I also know that different tensions (possibly lower) might have yielded more positive remarks from me. However, it was such a dramatic difference, to me, that I'll never consider kevlar again.
     
    #41
  42. travlerajm

    travlerajm Hall of Fame

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    You do realize that the topic of this thread is the concept of what happens when you string the mains 15-20 lbs tighter than the crosses? By stringing with this differential, it promotes the snapback effect that increases spin potential. The increased lateral movement of the mains also makes the stringbed much more comfortable for a given average tension. Using kevlar mains enhances the effect.

    By stringing the crosses 5 lbs tighter than the mains, you tried something that represents almost the exact opposite of the "ESP" setups that are the main topic of this thread. Stringing crosses tighter than mains takes away the snapback effect that is needed for good spin and comfort.

    Another point: kevlar, if not pre-stretched, requires a break-in period before it softens up. It feels much softer after the first hour.
     
    Last edited: Jul 10, 2013
    #42
  43. moonballs

    moonballs Hall of Fame

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    Travlerajm or others, I think the concept of the normal over lateral stiffness ratio is a good concept but I am still struggling to see how lateral stiffness is approximated by the crosses stiffness. Thx
     
    #43
  44. Bhairava

    Bhairava Rookie

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    So one one has tried this particular setup?
    I'll start stringing on my own the next week, and I think I'll start with a full bed poly at high differential tensions. Something like 24kg/20kg, with the main string prestreched and the second one without prestrech. I'm used to poly that last 6-8hours, so if this setup will give me extra spin and will last 6 hours too will be my actual setup, waiting for some kevlar&zx in the next weeks ;)
     
    #44
  45. travlerajm

    travlerajm Hall of Fame

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    I look forward to hearing how this works out. Pre-stretching the mains only will definitely increase the effective differential.
     
    #45
  46. newyorkstadium

    newyorkstadium Semi-Pro

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    Travlerajm, can I divert you to ricardo's thread. He asks some good questions that I think only you know the answers to.

    http://tt.tennis-warehouse.com/showthread.php?t=469801

    If you use a string in a full bed, can you just string too high instead of pre-stretching?
     
    #46
  47. travlerajm

    travlerajm Hall of Fame

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    I played singles last night.

    In warm ups, I was having fun hitting spaghetti-string style spins with my T5. Really loved it for groundies. Didn't feel quite comfortable with the control at net though, as the stringbed was a little softer than I prefer now that the poly had lost more tension. So I elected to play the match with my Blade.

    My Blade stringbed had soften up a little too, but still good control.

    The spin potential had increased some. This made my Blade the perfect racquet for twist serves. I ended up played the whole match using nothing but slow twist serves on both first and second serves. I could get the bounce to go about 8-ft high, with the bounce direction quite unpredictable. I even got an ace on a 75mph serve when it kicked unexpectedly 4 feet sideways and my opponent ( a solid 4.5 with excellent defensive skills) couldn't reach it.

    This opponent usually plays me close, but yesterday was the first time the score was not close, as the extra rpm on my twist serve and groundies really bothered him. I actually didn't play that well, but I could rely on the spin as a weapon. I got many easy points by following my wicked slow twist serve to the net.
     
    Last edited: Jul 12, 2013
    #47
  48. JT_2eighty

    JT_2eighty Hall of Fame

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    I was thinking more about this setup, and how it relates to my preferred setup of Gut/Poly. Also, how many other people have noted that Gut/Poly "gets better with age" to a point (before the poly completely 'dies')...

    Could the "better with age" be partly attributed to the poly losing substantial tension over time, thereby increasing the effective tension differential to similar numbers of your kevlar/zx setup? Gut typically holds tension very very well, so after a few days, weeks, etc... one may end up with an effective differential on their used gut/poly near 14 lbs or more? (Gut loses about 5-8 lbs over normal hitting while poly can lose up to 15-20 lbs or more over the same time)

    I recall one of my first times stringing Gut/Poly, and I did a terrible job of tying off my poly (and probably also in clamping effectively), and over time my racquet head deformed from the standard Oval shape to almost Circular. I didn't measure it, but the racquet length definitely got shorter, evidence of the gut holding it's tension while the poly lost Tons of tension.

    During the last few matches of this stringjob I was accused of using spaghetti strings by a regular hitting partner, as my kick serves were bouncing waaay higher than normal. I thought it was due to lower tension but didn't really think about the tension *differential*... hmmm
     
    Last edited: Jul 12, 2013
    #48
  49. travlerajm

    travlerajm Hall of Fame

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    Absolutely. I think it is the same effect.
     
    #49
  50. allenkau

    allenkau Rookie

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    I think TravelJam allured to this earlier in the thread also. I am hitting the 40 hr marks on my Gut/Poly on an very stiff 2013 APD. Spin has gone up lately. The bed feels soft but yet my shots will stay in.

    Using the same line of thinking, I prestretched my 17 Co-Focus on last night's new string job to hopefully get the DEAD poly effect from the beginning. I also strung it at 58 / 53 and the racket did get slightly shorter after the string job was done.
     
    #50

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