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Stringmeter: An Ode to Accuracy

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The stringmeter is a much maligned and wildly misunderstood instrument that should be essential…ABSOLUTELY ESSENTIAL…for all stringers who are concerned about accuracy, consistency and quality in the string jobs they are producing.  It is also a useful tool for serious tennis players who want to monitor the tension loss of their strings so that they will know when it is time for replacement.  It can also be used to measure the quality of the stringjob in your racquet.

Ask the vast majority of stringers about a stringmeter and you will generally receive a luke-warm response at best.  You will likely hear it is cheap and inaccurate, but can serve as a general guide as to how much tension loss the strings are experiencing.  You will hear it is best used after stringing to get a measurement of the current stringbed tension. You will hear that this tension will be different from the tension used in the stringing process because of a myriad of factors.  You will hear that you should just ignore the reference tension and go with what the meter gives you because it does not measure real tension.  You will hear that the tension it shows on the strings can vary from string to string because of string length and not to be concerned if each string varies from one another.

We believe most of these statements are off base.  We believe, properly used, the stringmeter is a very precise and accurate instrument.  It can be used to accurately measure the desired tension on the main strings (the ones that run vertical).   The cross strings, however, will show a lower tension than the mains due to the friction involved during the installation process.  Depending upon the tension used, it is not unusual for the cross strings to measure 10 – 20 pounds lower than the mains.  This is to be expected.  All adjacent strings should offer very similar measurements to one another, mains and crosses.  The crosses may tend to vary slightly more than the mains, but neither should be significant.

First I feel the need to let readers know that the spring in the Stringmeter must be free and flexible in order to be accurate.  Sometimes this mechanism does stick and when that is the case, the readings can vary wildly.  If your Stringmeter is not functioning smoothly, add a drop of lithium grease or oil on the spring mechanism in the area under the “V” where the small loop and two large loops meet.  This will make sure your unit is functioning properly.  The spring, in general, does not go bad.  In an extremely rare instance where it may, each Stringmeter comes with a lifetime warranty so all you need to do is replace it free of charge.

We generally only use our Stringmeter to measure the tension in the mains.  When we are finished stringing a racquet we have developed our technique to the point where our main strings are all measuring the exact tension that was installed.  It takes time and considerable effort to reach this level, but the outcome is a much more consistent and superior playing stringbed.  The effort needed to reach this level of proficiency is clearly worth it.

I used to be in the camp who would tell you it was not possible and was not important.  I used to believe the Stringmeter was inaccurate.  I suppose I was in a state of denial.  Always taking pride in my work I was able to generate consistent DT readings and I reasoned that was the most accurate way of measuring consistency and quality.  Two years ago I was challenged to create a stringbed that offered consistent measurements with an average of no more than +/- 2 for each main string.  I started messing around with the Stringmeter and was extremely frustrated because I was unable to achieve that level of accuracy.  I reasoned the Stringmeter must not be designed to measure exact tension and used the text on the Stringmeter web site to support my misguided belief.

Today I believe differently.  I believe the Stringmeter is an incredibly accurate instrument.  I have realized my failure to embrace it was a product of pride.  I simply could not believe that with my level of experience and using the best equipment available that my stringbed could possibly be inaccurate.  It was frankly unfathomable.  I had to really make a commitment to opening myself to a world of new possibilities in order to find the light and make adjustments that now allow me produce a more consistent and accurate stringbed.  The Stringmeter is now my best friend and I can not believe how many years it sat in my tool box, rarely used and unfairly disrespected.  I now embrace it.

I would challenge my stringing colleagues to use the devise to measure the consistency of the main strings in any racquet that has recently been strung.  Is the tension shown the same as was used to install?  If not, how much difference is showing?  When setting the meter, I use a small piece of tape to secure the outer ring so that it will not move/rotate when measuring tension.  For me this is helpful so that I do not have to constantly fiddle with the rotating scale.  If the main strings are not showing consistent readings, it is not because of the tool, rather the readings are indeed reflecting the end result.  Yes, this may be a hard reality to accept, but in order to reach a point of true stringing excellence it is important to get to a point where the tension you used is the tension that is showing on each main string.

I believe that the Stringmeter was originally designed to be much more precise and accurate than the current web site describes.  I would not be at all surprised to find out that the marketing team had to sort of backpedal on the issue of being a true tension measurement device because the results for most stringers were not in line with the tension applied.  This created marketing issues on multiple levels.  Afterall, who would buy a device that showed their work to be lacking in quality?  That would be an incredibly hard sell.  Rather, units would move better if they did not fight about accuracy, but rather focused on the secondary purpose of the devise…it’s ability to measure a change in string tensions.  Yah…that’s the ticket!

What do you think?  We’d love to hear your opinions on the topic.  Is the Stringmeter precise and accurate, or are we crazy as a loon?

 

 

32 thoughts on “Stringmeter: An Ode to Accuracy

  1. jayceeparis on said:

    At last someone has perfectly recognized the real value of this remarkable little measuring device which is the indispensable tool for a conscientious stringer who wants to improve the quality of his work. Without the possibility to control the tensions that have been actually strung into a racquet, it is impossible to achieve a high level of competency as a stringer.

    Most stringers do not have the humility to believe that the readings of a Stringermeter are accurate and consistent. The truth is that this device is almost perfectly correct, it reveals the mistakes that we make when stringing or confirms that we have done a good job.

    I have the same Stringmeter since more than 15 years and I use it every time I string a racquet. I could not work well without it.
    I am very pleased to see that John is encouraging stringers and players to use this device, it is the key to understanding what is really happening in the string-bed, both before and after stringing. When well used this is the perfect “yard-stick” and the only way to improve the quality of the work of a stringer. If you want to obtain accurate and consistent results when stringing, you must use a Stringmeter and be humble enough to trust it, to believe that it is telling you the truth, and that when the “set tension” is the same as the average tension on the mains, then you have achieved WYSIWYG efficiency, which is the ultimate goal for a highly competent pro-stringer.

    Trust the Stringmeter, it really works well.

    John Elliot

    Reply
  2. Julian on said:

    John,

    I understand how the Stringmeter can be a very effective tool. Do you believe the iPhone app “racquettune” can serve its purpose to measure tension loss? Thank you for your valuable input. BTW. I am still working with lowering my tension under 52lbs.

    Reply
  3. ggtennis on said:

    We have been using and studying the app you mention. I have found it to be consistent in measuring tension loss. Many times it is accurate in zoning in on the exact reference tension, but this can vary according to string type and sometimes hybrids and low tensions can give it trouble. We have just started testing the revised version and see there is now a low tension option.

    In terms of measuring tension loss, we do believe it to be an effective tool as long as the settings (string type, gauge, racquet head size etc) are not altered and the method used to strike the stringbed is consistent. The DT measurement using the Racquettune app does not seem to align with my ERT.

    Reply
    • Kf on said:

      In terms of ERT vs. RacquetTune… If you measure the same racquet on both devices, how different are the dynamic tension readings? Can you show some reading data from buth methods on same racket?

      For reference, I strung a pure drive roddick, jet method, hybrid with alu power mains and babolat origin crosses, with the jet reference tension set at 51 lbs, on my lockout machine. Initial result was 47 lbs, 33 N/mm. After 3 hours play over 3 days, Im currently at 42.9 lbs, 30.0 N/mm (-8.8 %).

      I’d like to know if the ERT reads higher or lower, and by how much, so the results make sense. As it stands, the 30.0 number looks very low, but maybe an equivalent ERT reading would be a bit higher???

      Reply
  4. danno on said:

    I’m curious about the ert 300 and whether it’s worth the investment. will the string meter suffice? Also Stringway has a similar product to the ert. What would you advise?

    Reply
  5. GGTennis on said:

    The ERT 300 and Stringway tool both measure stringbed stiffness using frequency. It is certainly valid. There is a new tool coming out that should be priced in the neighborhood of the ERT that will measure actual stringbed tension. That tool to me is far more interesting and I would suggest holding off until that tool hits the market. It is called a String-a-Lyzer.

    Reply
  6. Mike on said:

    Is the string-meter accurate for measuring tension loss, both immediately after stringing and after playing with the strung racket?

    Can it measure all types of strings, like multi’s, syn gut, nat gut etc?

    Reply
  7. GGTennis on said:

    Mike – The answer to both questions is yes!

    Reply
  8. Mike on said:

    Great. I will save money and get the stringmeter then, over the ert 300 or an ipod/iphone. Thanks

    Reply
  9. William on said:

    John,

    I just bought a tourna string-meter.
    I found out that when using it to measure tension.
    It seems to hurt the string a little bit. It is not severe, but I can notice a mark/scratch after using.
    I just used it on polys.
    Does this happen to you as well?

    Reply
  10. GGTennis on said:

    Interesting. Are you sure you are seeing damage? I have been using them for years and have never seen any damage from their usage.

    Reply
  11. William on said:

    Well, I wouldn’t say damage.
    I myself wouldn’t care, but I am afraid if I string it for others.
    They might ask questions.

    What I say is, after using, I can notice a small change in shape where the pin touches the strings.
    You don’t see any changes?
    I ordered one so I can see if I am doing right with JayCee Method.
    My stringway ml 100 is on its way.
    Can’t wait.

    The mark I see. It’s in the green circle.
    https://plus.google.com/u/0/photos/114261631261201800900/albums/5876007111071878385/5876007112684377554

    The way I use it.
    https://plus.google.com/u/0/photos/114261631261201800900/albums/5876007111071878385/5876007187046943234

    hope to get your respond soon.
    Do you see that small mark as well?
    Is it harmless?

    Thx

    Reply
  12. Dale on said:

    I just strung my first racket using the Stringmeter as a guide. I went for 50lbs on the mains and it was reading close to that after I strung just the mains. After I was done with the crosses at 50lbs, the mains were at 65lbs! The crosses were reading 35-40, but I was most shocked by the 15lb increase in the mains.

    Since then, I have done 45lbs main and 60lbs cross to try to even out the tensions between the mains and the crosses. After that try, I got 60lb mains and 45lb crosses. Do you think its ok to go 15lbs or more higher on the crosses in an attempt to even out the stringbed as much as possible?

    Reply
  13. GGTennis on said:

    Whoa! No need to get the mains and crosses to equal tensions. Achieving that goal could damage your frame. I would advise to keep any difference between mains and crosses to be no more than 4 pounds, with 5 pounds as a maximum difference. You are NOT trying to get the mains and crosses to the same tension. With synthetics the tension difference between the mains and crosses should be approx. 30%, with the crosses 30% lower than the mains. With polys it is best to have the difference between 20 – 25%.

    Reply
  14. Dale on said:

    Thank you for your insight. I will not go so high with the tension on the crosses from now on. I forgot to mention I am using the Gamma X-2 dropweight machine and Gosen 18 gauge nylon string.

    I was reading the manual for the stringmeter and it says that the measurement on the cross strings should only be used relative to the other cross strings, implying that it is not an accurate measure of actual tension on the crosses and you can’t compare the number with the mains. I would like to know what your take is on this.

    When my mains are reading 60 and the crosses at 40 on the stringmeter, I do notice it is much easier to move the cross strings up and down than move the mains side to side. My thought is that this is because the crosses are indeed at a lower tension?

    Reply
  15. Bill on said:

    I just purchased the Tourna stringmeter for a month along with my drop weight stringing machine and it’s been very accurate measuring both my own string job as well as my last racket where I paid a shop for. I just measure my cross today which I strung @ 51 pounds and the stringmeter gives me average reading of 36 lbs. So this really shocked me at first. Then I measure my other racket strung by pro shop and I see similar difference between between main and cross. So reading this post here it confirmed what I saw was expected. I’m string poly main @ 48 and multi cross @ 51 on Wilson Pro Staff 90.

    Reply
    • GGTennis on said:

      All sounds right. Remember the Stringmeter is a useful tool as long as you understand how it works and do not panic when you measure the cross strings and see they are not at the exact tension that was pulled.

      Reply
  16. Bill on said:

    Like Dale, I see the same increase in tension after completing the crosses.
    Mains are at 58 but after doing the crosses they measure 71. Racket bed hits like it is 71… Is this normal and what is the reason for the significant increase?

    Reply
    • Dale on said:

      After stringing about 30 times, I now learned that the mains must be strung 10-15 lbs less than the desired tension when using the X-2 machine. This is because each woven cross string will increase the main tension by a lb or so.

      The reason is because when a cross is woven through with tension, it is acting to lengthen the main string by putting it into a zig zag formation when it was previously straight. Each weave acts like there is a small weight hanging on the main string. Since the main can’t move at the ends, it is stretched and the tension goes up.

      Reply
  17. GGTennis on said:

    I do not understand the results being shared here. When properly strung the racquet’s main strings will measure the set reference tension (or reasonably close) when the stringing is complete. I have never measured strings using the string meter on a partially strung racquet. The tool is most useful for me to measure AFTER the stringing is complete. I look for uniformity among the main strings and I look for it to measure at the set reference tension. That is the goal and that is what I achieve. The cross strings will typically measure 25 – 35% lower than the mains unless the cross tension is changed or the pulling time is extended. When stringing with poly, we extend our pulling time and strive for a difference between the mains and crosses of 20% – 25% (with the crosses being lower than the mains).

    Reply
    • Michel Martineau on said:

      I have two stringmeter and there is a difference in the readings of 8 to 10 pounds between them. How am i to know wich one to use ? Both are new and looking perfect.

      Michel Martineau.

      Reply
  18. GGTennis on said:

    We no longer use frequency for measuring/monitoring tension with poly-based strings. We use our RDC but it is an expensive unit. There is a new device that measures string bed tension and it is a far better instrument for such measurements as it provides data similar to an RDC stringbed deflection. It is called a tension-analyzer. I do not have the web site handy, but I think you should be able to google it. They also have a facebook page.

    In terms of your reading, the measurement sounds about right. The ERT and Racquet tune app provide similar data elements. The problem I have with them is that the readings are not precise enough. It takes a change of 2 – 4 pounds to move the data point. Also for some reason as poly ages, it transfers sound waves differently and gives lower readings. We discovered this because the stringbed stiffness and tension reading do not reflect the same loss as the frequency measurements.

    Reply
  19. Michael on said:

    I just received my StringMeter, and I measured two freshly strung rackets – one strung at 50/48 with Solinco Tour Bite Soft 17g (soft poly), and another at 54/52 with Pro Supex Maxim Touch 17g (soft multi). Both rackets are Wilson Pro Staff 6.1 95, and the stringer is drop weight.

    To my surprise, the StringMeter showed 70lbs for the poly, and 55lbs for the multi.

    Do I understand correctly that the actual absolute number the StringMeter is showing is meaningless, and that it is only intended to measure relative tension loss for the same string in the same racket over time? So comparing tension of the poly to tension of the multi with the StringMeter does not make sense?

    Reply
    • GGTennis on said:

      Michael,

      Those numbers do not make any sense to me. Something must be askew with the dial. The numbers for the multi are in line with where they should be, but the poly seems to be way off. The number is not meaningless. It is always relatively close (+/- 2 – 5) to the tension set on the machine when strung properly. I am at a loss to explain the readings you are finding. Are you looking at multiple strings (mains) across the stringbed?

      Reply
      • Michael on said:

        Yes, I measured several mains, and they are all within 68-70lbs range. The crosses are around 60lbs.

        I have measured about 8 different rackets (all multis), and they range between 30 and 55lbs (mains), depending on how old the strings are.

        Intuitively, the high tension number shown for the poly makes sense – if I try to bend the string with my fingers, poly is much harder to bend than any multi, so given that the tool measured the effort to bend it, the reading for the poly should be significantly higher than the multi.

        However, this was my first time stringing poly string on a drop weight machine. So it’s possible that I did something wrong and strung it much tighter than intended. The weight on the arm was positioned lower than I had it for multis – at 50/48lbs, but because poly string didn’t stretch at all when stringing crosses, I had to move the arm from 11pm position to 3pm position (clockwise) before attaching the string, so that I could pull the string to the position when the arm is horizontal. Is that how poly should be strung on a drop weight machine?

        I’m going to string another racket with Black Widow 18g today (another soft poly), so let’s see how that measures. I definitely don’t want to play with a racket strung at 70lbs (my elbow and wrist won’t like that at all).

        Reply
        • Michael on said:

          Actually what I meant was I moved the arm from 11pm to 2pm position, so that after the string was attached, it pulled it to 3pm position (horizontal).

          Reply
  20. Dale on said:

    This is my theory on what happened. You strung the multi and poly using the same technique but the surface of your poly string has less friction than the multi. When you did the crosses, more of the force from the drop weight transferred into string tension which ended up tightening the mains to around 70.

    Reply
  21. GGTennis on said:

    It sounds like the stringing technique is fine. I am not sure why you are seeing the readings you are reporting. It’s a puzzle for sure. Make sure the dial is not moving. Try setting the gauge at a static point and tape the wheel so that it can not accidentally move. Unintentional movement of the dial is what seems to me to be the most reasonable explanation.

    Reply
    • Michael on said:

      Last night I strung another racket (same model) with Black Widow 18g. I was super-careful while stringing, and made sure every pull was consistent. The tension was again set to 50/48lbs.
      Then I measured the tension of the mains – it was 60lbs. By the way, pretty most of mains measured exactly 60, so that confirms I was consistent. Crosses were 50lbs.
      Also, I watched the dial and made sure it didn’t slip.

      I can definitely feel more resistance when trying to twist poly than when trying to twist multi. So I’m curious, how can you expect to see the same measurement when stringing polys and multis at the same tension? The strings are completely different in their natural stiffness, so it seems to me they should give out different readings when strung at the same tension.

      After playing with StringMeter, I can see it’s an accurate instrument for measuring relative tension. For example, it can accurately show that all mains have the same tension. However, I don’t think it was ever intended to make comparative measurements between different types of strings, or rackets, or stringers, etc. I’m inclined to believe it is only accurate within a scope of a single string job. So that when it shows 70lbs on a racket with Tour Bite Soft 17g, and 55lbs on a racket with Maxim Touch 17g, it does not mean that the first racket is tighter. We can’t make that statement, because the strings are so different. If you measure the “tension” of a nail with a super-strong StringMeter, it would show much higher tension than any tennis string, even though the nail is not under any tension. Does it make sense?

      Also, I played with that Tour Bite Soft last night – it felt great! The level of softness and comfort was on par with my usual Sensation strung at 54/52, so there’s no way it is really at 70lbs.

      Reply
      • Michel Martineau on said:

        Hello Michael.

        Il you want a more accurate reading with poly string you need to recalibrate your stringmeter.
        They use nylon string to do it and it is much softer than poly.

        Go to RSI apr 2011 vol 39 no 4-47-0047 and you Will find how to do it.

        Michel Martineau.

        Reply
  22. Michael on said:

    Oh nice! That makes sense. I will certainly do that next time I string. Thank you.

    Reply
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