RacquetTune way off?

Discussion in 'Strings' started by JTJet, Feb 6, 2013.

  1. JTJet

    JTJet Rookie

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    I realize that RacquetTune isn't going to always be accurate, but my last string job had a difference of 9 lbs. Should I be worried? I'm using the default string factors also.
     
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  2. Charleyk24

    Charleyk24 New User

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    Me too
    It was used good like 1-2 lbs different max
    It is going up 5-9 lbs ( poly &syn)
     
    #2
  3. mikeler

    mikeler G.O.A.T.

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    If you measure it off the stringer, most strings will lose between 10% to 20% of their tension from that reference tension. String at 60 and expect anywhere from a 6 to 12 pound loss depending on string type.
     
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  4. ellipticality_224

    ellipticality_224 Banned

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    My mom has that on her Ipad, I snagged the iPad for a week while she was gone and tried it. I was not impressed by it, It would start off +/- 5 pounds by what I strung it at (I only used fresh strings to test it). And every time I hit the bed with a spoon it would start off fairly accurate, and with each hit the tension on the app would start to read higher and higher, by about a half a pound each hit. But still a very impressive app for all the features and the fact it used only tunes from the strings to get a fairly accurate gauge on the string tensions
     
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  5. JTJet

    JTJet Rookie

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    Really? I strung at 58 and got a reading of 49. Would this be a normal occurrence fresh off the stringer?
     
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  6. Centerforward71

    Centerforward71 Rookie

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    Whattt. Man I know you got alot of clout around here but I seriously disagree. i won't settle for anything more than 5% max loss off the machine on my string jobs. 10-20 that's way off and your never getting what you asked for. I ask customers do you want strung at X tension or off machine at X tension. And this is with any machine I may use.

    By the way I have had large differences on strings that I didn't measure but usually only 1-2 lbs
     
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  7. Centerforward71

    Centerforward71 Rookie

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    No no no way. You got to measure the string trust me. Also use a good metal tool like a soup spoon to twang the strings. Gotta measure strings I had same issue at first.
     
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  8. v-verb

    v-verb Hall of Fame

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    Strung at 35 lbs, measured on RT at 33. Pretty accurate I think
     
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  9. JTJet

    JTJet Rookie

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    Could you clarify what you mean by "measure the string?"
     
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  10. Ramon

    Ramon Hall of Fame

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    I use a calibrated drop weight stringer and my jobs always measure 7 pounds high. I used to have other people string my racquets whose RacquetTune measurements were about 6-10 pounds low. My intuition tells me that if you measure the string factors accurately, RacquetTune is more accurate than the stringers. Don't rely on the default string factors for accuracy. It's ok to use them if you are only concerned about measuring relative tension loss.
     
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  11. nightfire700

    nightfire700 Rookie

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    That leads to a question that I have been thinking of asking. When one mentions a tension of say 55 lbs does it mean the string is strung at that tension or does it mean the tension one can record 1-2 hours post stringing as I understand that lot of strings lose quite a bit of tension during that time as it settles down? Also will pre-stretch help here and if yes why isnt it used everytime?
     
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  12. Centerforward71

    Centerforward71 Rookie

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    Read the racquettune instructions for getting the string specific factor number. It requires putting single strand under tension and twanging string so that app can get the string factor.
     
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  13. Centerforward71

    Centerforward71 Rookie

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    I hate to break this to you all but a lot of the stringing that occurs at tennis shops are not very good or accurate. A few factors include uncalibrated electric machines, stringers who dont really care about accuracy, and other stringers who aren't good stringers based on not paying attention to detail and last is that alot of 2knot jobs instead of 4 knot which can lead to greater innacuracy but also saves string for the shops profit.
     
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  14. esgee48

    esgee48 Hall of Fame

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    Nightfire: If you use a LO, the machine stops pulling when it reaches ref tension. The string, since it is under tension, starts to lose that same tension so that it no longer at the tension the machine locked out at. If using DW or CP, tension starts to be lost as soon as the string is clamped. Again, the string will lose tension to relieve stress. Mikeler is correct that strings will ultimately lose between 10 and 25% of the desired ref tension. The low end is prem gut and the high end is poly.
     
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  15. GlenK

    GlenK Professional

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    I've had no issues with RT as long as I have the data set right. It is extremely consistent and has helped my become more consistent in my stringing processes.

    Right now RT is showing a reading of +/- .1 lb from job to job. It does read a littler higher than reference right off the stringer. I average 3-4% 24hr tension loss vs. right off stringer.

    Been using it now for over a year and anytime I've had issues it turned out to be user error.
     
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  16. Buford T Justice

    Buford T Justice Semi-Pro

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    On my end, RT seems to be fairly accurate....or at least good enough.

    Two Steam 99S strung to 59 with Gosen Polylon 16 (from TW....not sure what type of machine they use), measured 54 on RT when I received them and before play. That seems reasonable enough to me for a cheap poly that has settled out for 2-3 days after stringing. I used the Gosen Polylon string factor thats already included in the app.

    The same frames, after 5-6 sets of use, measure out around 44 on RT.

    On the next stringing job, I am going to take measurements more frequently to see how fast tension actually drops off (i.e. does it drop from 54 to 44 after just a few minutes of use and hang out there, or is it a slow progression downward and then a plateau at 44).
     
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  17. mikeler

    mikeler G.O.A.T.

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    What what what!!! I think we are having some kind of disconnect here.

    Look at the tension loss RSI reports for a wide variety of strings:

    http://www.racquetsportsindustry.com/articles/2012/01/string_selector_2012.html
     
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  18. Buford T Justice

    Buford T Justice Semi-Pro

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    #18
  19. Buford T Justice

    Buford T Justice Semi-Pro

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    I think what charts like that show is that, the tensions we truly "like" are actually alot less than we think (i.e. if I say I "like" 59 lb with "X" string, I am really "liking" something far less as the stringbed is not at 59 lb for very long (if at all))?
     
    #19
  20. McLovin

    McLovin Hall of Fame

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    You know, that's a good point. And it *may* be the reason many people like string 'A' and not string 'B'. If string 'A' loses more tension than string 'B', this might result in a completely different feel, assuming they strung both strings at the same tension.

    Oh, and Buford T Justice, "do the letters F.O. mean anything to you?" :)
     
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  21. Buford T Justice

    Buford T Justice Semi-Pro

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    "Smaaaht alek"

    hehehehehehe

    One of the top movie characters, and movies of all time! Pretty sure I have the script memorized!
     
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  22. McLovin

    McLovin Hall of Fame

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    Agreed. One of my all time favorite quotes is:
     
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  23. Buford T Justice

    Buford T Justice Semi-Pro

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    I think there has to be something to this.

    And, I think that, if a string is of the type that perhaps drops initial tension fast (like apparently all polys do), but stabilizes ("plateaus") there, the initial (high) string tension loss may not matter so much as one can just string higher than desired and allow the string bed to settle out where they actually want it (and then maximize play time at the desired tension). I know there has been more than one time Ive "accelerated" that settling out process by standing on the string bed after placing the frame in the sun!

    Of course, this has some limits and has to affect the strings "feel" (as the string has a limited elongation) and a stringbed at 55 lb initially must feel a little different than a stringbed initially string to 65 lb and allowed to settle in at 55 lb.
     
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  24. mikeler

    mikeler G.O.A.T.

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    Most of the tension loss from my measurements and others occurs during that first 24 hours. Then you tend to get a little more the first time or two out on the court followed by stabilization. Other strings will keep dropping each time you play. Those are the hardest to deal with because it is like playing with a different string job each time out and who would want to keep switching string jobs all the time? :)
     
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  25. Centerforward71

    Centerforward71 Rookie

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    This is why you use a product like racquetune to at least have baselinies and when you report loss of tension or not its with some real knowledge.

    Yes the tensions we like are not what we string at, its your job to find that tension and string and its the stringers job to match it for you and does not mean to put the racquet on the machine at that tension. Thats the difference between a good job and not. Items like racquettune are great as whether it is +/- on true measurement it can give you the measurment at a point you like and then you match that to really be precise.
     
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  26. Centerforward71

    Centerforward71 Rookie

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    FROM THE ARTICLE: "Test Procedure. All strings were tensioned to 62 pounds and allowed to sit for 200 seconds. Then the string was hit five times with a force equivalent to hitting a 120 mph serve."

    I said off the machine, and I didnt say hit 200 seconds later with 5 strikes the force of 120MPH serves which is Significant.

    Also 62 LBS is a BIG PULL on any material and will definitely cause higher loss of the machine and with some striking and that kind of stress will also increase the loss....... buttttt

    I will also challenge some of these results. I PERSONALLY PLAYED geneses TWISTED RAZOR at strung at 62 on a HEAD spped MP 315 16x19 for about a year. measured of the machine at about 58 +/- 1lb. After one session would measure around 52-54 (Thats about 10lb loss so 18% or so) and would eventually get down to about 46-48 which thats about 6 hours which at that time I would cut it. For the below stat to say that this string loss 18lbs after stringing at 62 and struck five times with power serves I CHALLENGE the validity of this and will string another racquet like this and will record the findings and post them here. The below reading is saying that a job at 62 is 44 LBS after 5 strikes of a serve, like I said WHATTT ? I hit pretty hard and have a power game on all wings pretty much so I put alot of stress on my strings, alot more than just 5x120mph serves..

    ***********************
    FROM ARTICLE:
    Genesis
    Twisted Razor 16L
    Polyester
    1.26
    259
    18.67
    ***********************

    I am not trying to argue with you but I want to make sure that we are getting good data here and that folks that come to these forums can depend on information thats valid and not trash. What I wrote above was proven over a years time, time and time again over 40 or so of my personal string jobs. I realize the RSI is what it is, but so is the government and the vatican and we should confirm and not trust everything you read. I AM GONNA TEST and post when I can there is something wrong with those numbers or I am not reading something right.
     
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  27. mikeler

    mikeler G.O.A.T.

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    If you read the RSI reviews, they will measure tension loss 24 hours after stringing. It is usually in the same ballpark as the tension loss in that table that is linked to in this thread. So that test seems to do a reasonable job at approximating tension loss for some strings. Why your data on twisted razor does not match up well, I have no clue.

    The stiffness test is a whole separate topic and THAT data does not seem to correlate with what I feel in my arm. With both tests, it is a small sample of lab data. Take it with a grain of salt and use it as a guide. Personal testing is always best and Greg Raven even states this in the January issue of the magazine last month.
     
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  28. ten11

    ten11 Rookie

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    This is from MRT supplement study guide.
    "This factor causes more confusion than any other. If you string two identical racquets with different gauge (but otherwise identical) strings and perform the palm test with the strung racquets; the thinner gauge will have a higher harmonic pitch or “ping.” Most people would logically assume the thinner string is tighter. Even though we found little difference when measured statically (i.e., RA Test), the racquet with thinner gauge may feel less stiff in play, due to the greater elasticity of the thinner string. Dr. Brody reports that, generally, a 17 gauge string will be about twice as elastic (100%) as a 15 gauge string, all other factors being equal. This increased elasticity results in lower dynamic stiffness (meaning the strings will feel more elastic) during ball contact. A player changing to a thicker string (for greater durability, for example) may complain that the “ping” isn’t the same as with his thinner gauge string. However, increasing tension to reproduce that harmonic pitch would probably result in a stringbed stiffness too hard for his liking. So string for feel, not for the “ping.” "

    This is from apple racquet tune page:
    With racquetTune you will always have the optimal racquet to play with. Tap the strings and racquetTune will use the sound to calculate the tension with high accuracy.

    So you can draw own your conclusion if you should even use racquet tune.
     
    Last edited: Feb 7, 2013
    #28
  29. Buford T Justice

    Buford T Justice Semi-Pro

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    Nice Magnum PI work ten11!

    I am not well versed in RT, but doesnt the app use a "string factor" that accounts for string thicknesses? I thought when I looked at the string database in the app, that the same string, at a different gauge, will have a different string factor. I think they even have a calculation in the app for determining the change in string factor with string diameter (in mm).
     
    #29
  30. ultradr

    ultradr Hall of Fame

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    We use the number as a reference.

    Strings are elastic but not 100%. It goes thru plastic deformation and thus lose tension.

    Don't you know nothing lasts forever in life? :)
     
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  31. ten11

    ten11 Rookie

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    I believe the software might have it in consideration but I still do not give the credit to it. There might be other variables it missed. So basically it might be garbage in, garbage out.

    So true. for both reference and the question.
    I string strictly based reference tension and take a note of it. Same machine, same technique, same string if possible and adjust accordingly in reference to previous job. If I use a new string, start from scratch again.
     
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  32. Buford T Justice

    Buford T Justice Semi-Pro

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    And when it relates to strings.....I dont think any time soon we are going to see non injurious / playable "everlasting strings".....in an era of $16.95 poly string sets! Most spend far more on strings over the frame life than the frame itself.....so follow the $ :)

    Although....I have so say I am digging this Polylon $1.70 per frame gig:)
     
    #32
  33. mikeler

    mikeler G.O.A.T.

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    There are 2 ways to use the software. You can pick a standard string factor that accounts for string material and gauge. This is great for measuring relative tension loss but may or may not be good for absolute tension readings. The app also describes a methodology for determining a custom string factor for those who are also interested in absolute tension. Most of us are just interested in tension loss, so we use the standard string factor and it gives us a good indication of how the string behaves over time. It's a $2 app, if you don't agree with the methodology then don't buy it. At least understand it before you criticize it though.

    PS You still hitting with the PSTs?
     
    #33
  34. ten11

    ten11 Rookie

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    I thought I understand it but definitely not convinced. That is my opinion.

    Those are sweet sticks, but this winter I have moved on to pt280/630. I am thinking to go back to it in spring, either the pst+ or the new apd+ or pd+. I was looking for more pace from my stroke to switch to heavier stick but now ready for more spin. The plus length also helps.
     
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  35. JT_2eighty

    JT_2eighty Hall of Fame

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    I don't know anything about RacquetTune, but I think a lot of people here are confusing "REFERENCE TENSION" with "ACTUAL TENSION".

    They are never the same value, as soon as the racquet is strung and taken off the machine, tension loss begins.

    This may not be common knowledge but should be. There are many threads that go into depth about this.
     
    #35
  36. jmnk

    jmnk Professional

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    if i may ask - how did you measure the string tension while the string is still on the racket? as in - how do you know that it went from 62 to 54 to 48?
     
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  37. db10s

    db10s Hall of Fame

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    They use a prince NEOS 1000 or 1500, one of the two IIRC. Both are lock out.
     
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  38. JTJet

    JTJet Rookie

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    So, is it safe to conclude that off the stringer, strings will lose 10-20% of their tension. The strings "actual tension" will be 10-20% lower than the reference tension. The "reference tension" is the tension we have our racquets strung at, but we actually play with the "actual tension," which is 10-20% lower. The strings "actual tension" will vary when strung with two different machines with the same "reference tension." The only way to get a constant string job every time is to limit the variables.

    Also, my string job has lost around 16% tension as it was strung at 58 lbs and RacquetTune has a reading of 49 lbs. Even if RacquetTune isn't correct, this amount of tension loss is to be expected as my "actual tension" will always be 10-20% lower than my "reference tension."

    Am I correct to assume all these statements?
     
    #38
  39. Charleyk24

    Charleyk24 New User

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    First. sorry about my bad english.

    In my case
    initial restring tension reading w/ racquettune was used to good like 1-2 lbs differently from reference tension.
    That was good& ok w/me

    Now (i mean about 3month& 20 restring job poly& syn) Initial restring tension w/ racquettune is going UP (not down)5-10 lbs from reference tension

    So I suspected my machine( gamma progression 2 els) and digital scale( JSCALE-ULTRASPORT-50) first.
    Check the digital scale w/weight (of course check the weight w/ another commercial electronic scale) then calibrated my machine.
    Nothing wrong with that

    Next my stringing job?
    Same as last year
    Usually 1 pc job w/atw except hybrid job
    Nothing good but nothing bad I think

    I set up RT what RT want to do to me

    My conclusion??
    I don't now what's wrong but something wrong........

    Thank you for reading this
     
    #39
  40. Centerforward71

    Centerforward71 Rookie

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    Not sure I understand your question. All measurements are taken on the stringbed. Why would I measure off the racquet unless to get string factor ?
     
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  41. Centerforward71

    Centerforward71 Rookie

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    All good except to assume a 10-20% loss of machine I still disagree with that. If the machine is calibrated and the stringer does good work then I would say 5-10% is More normal. This is where racquettune comes in handy. Whether its accurate or not it can give you a baseline reading which you can use to verify string job.
     
    #41
  42. jmnk

    jmnk Professional

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    well, you took exception to (challenged) published RSI tests results. If I understand their procedure they just tensioned a string, hit it with a given force, let it be stretched at a constant length, and than noted the tension after specific time period(s). If you want to challenge those numbers you need to show how your results, with the same or very similar test procedure, differ. Thus you need to be able to accurately know what a tension on a single strand of string is. I find it hard to believe you can do that while you have a racket strung with full bed.
    That is unless you did what the racquettune developer did - string a racket with tension-measuring 'thingy' attatched to the racket (you can look for relevant thread here). But than his results, if I recall, were pretty much in line with RSI results.
    Thus I'm a bit confused how you are going to refute RSI findings?
     
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  43. Centerforward71

    Centerforward71 Rookie

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    Point is that the data is not one to base tension loss for the common user. My contention comes in the applicability of the data to a full bed. Perhaps I assumed that would be the assumption of who read my post. Point is even if there measurements are accurate that full bed tension is way more relative than this table other than the stiffness factor and even that can be seen differently. Does that explain my point ?
     
    #43
  44. mikeler

    mikeler G.O.A.T.

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    10-20% tension loss over the life of a stringjob is common for me.
     
    #44
  45. Centerforward71

    Centerforward71 Rookie

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    Now we agree 100% 10-20 over the playable life is very acceptable specially when most loss is initial and then stabilization occurs. I like strings that drop and sit which is what I don't like about the Luxilon strings they never seem to settle at least for my liking.
     
    #45
  46. Buford T Justice

    Buford T Justice Semi-Pro

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    I know Ive banged the Gosen Polylon drum a few times lately, but have you tried them? Ive been tracking 2 frames with Polylon 16 in RT and they seem to do just this.....they drop to a plateau and seem to hang there.

    In my case with Steam 99S frames strung at 59, they test at ~54 on RT after stringing and sitting a day or two, then after initial use go to 42-44 on RT and seem hang out there.

    The reason I bring it up as the price on these strings are impossible to beat. By the reel it ends up ~$1.70 per 99S frame....slightly more for frames which require more string. I can see why TW thinks so highly of these strings in their review (and it shows they are honest in their reviews as they cant be making much $ on them at $34.95 a reel).
     
    #46
  47. Centerforward71

    Centerforward71 Rookie

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    I'll give it a try, try genesis twisted razor also you'll be happy.
     
    #47
  48. mikeler

    mikeler G.O.A.T.

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    You know what, I was looking at those tension loss tables as a percentage. I just realized those measurements are listed in pounds. Now I know why there was a disconnect between us.

    So with that being said, the last 2 strings I used with RacquetTune to breakage were Gamma Pro (registered 12.5% tension loss) and Dunlop DNA (registered 13.5% tension loss). Since I strung at 50 pounds, those two numbers equate to roughly 6.5 pounds of tension loss. Now at 62 pounds there should be a greater drop in pounds tension but I'd think the percent would be roughly the same.

    RSI is saying those two strings lose 13 to 14 pounds of tension in their tests. If those pounds are actually percentages, then the numbers would be close to my measurements. As pounds tension loss, that is not jiving with RacquetTune.

    So let the discussion continue...
     
    #48
  49. Centerforward71

    Centerforward71 Rookie

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    Glad to hear it was a misread.
     
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  50. Oz_Rocket

    Oz_Rocket Semi-Pro

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    I've just started stringing in the past month with a basic 6 point drop weight. Downloaded racquet tune so FWIW here is my initial experience.

    Strung an Exo Tour Team Lite 16/19 with poly/synth gut hybrid at 48/50. Entered a custom hybrid string with the correct gauges and straight off the stringer it reported 48lb.

    Did my new Speed Pro 18/20 with Sonic Pro 17 @ 50lb and straight off the stringer it reported 54lbs. Given the very tight string pattern of this racquet compared to other 18/20s it isn't surprising that the frequency produced (and tension reading) would be higher.

    So while it looks to be great as a reference tool if it can read consistently, obviously things like variations in string densities for the same pattern are going to affect the reported tension.
     
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