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02-27-2013, 10:47 PM #1
Stringbed frequency to monitor string tension
As some of you may know, I'm pretty meticulous in measuring my equipment... (now get your mind out of the gutter)... I'm referring to my rackets.
See my head wt thread for example. http://www.badmintoncentral.com/foru...f-swing-weight
I also like to keep track of string tension and retention, so naturally I've also been measuring the dominant frequency of the stringbed. I do this because I want to keep track of my optimal string and tension preference. And also to make sure that my stringer is not messing up on me.
There are several tuner apps for smartphones that can do this, like CarlTune for Android, and ClearTune for iOS. It's quite easy, just strum lightly across the stringbed with your 3rd and 4th fingers like a guitar, and let it ring close to the mic on your smartphone.
The dominant frequency reading should be in the range of 1000-1300 Hz. Obviously the higher the tension and the thinner the string, the higher the frequency. From my experience, each 1 lb change in tension results in about 30-40 Hz change in frequency.
Also from my experience and contrary to previous notions, different rackets and brands do not affect the frequency as long as they are the same shape and string density. Therefore you can't compare between isometrics and oval / iso-ovals like Cabs or VZTF. Or between regular 22x22 pattern with Forza’s 96 hole monster with 24x26 pattern.
Now the purpose of this thread is to pool together in one place the various strings, tensions, and frequency readings. Hopefully this will allow us all to see how accurate and consistent our stringer is (which could be ourselves!), and also to have a common measure of understanding when someone says they’re playing with 28 lbs but in reality is only 24 lbs because their stringer has poor technique or uses a poorly calibrated manual crank machine. If you're using BG65 or VS850, this will also allow you to see how poor the tension retention is!
To achieve the highest consistency and accuracy then, please follow these requirements:
1. Isometric rackets with 22x22 pattern preferred. If not, please specify.
2. Must be only strung with ECP (electronic constant pull) machines, preferably by experienced stringers. No exceptions, otherwise you’ll pollute the data.
3. To allow for tension to stabilize after stringing, must wait for at least a week or play for a few hours before measuring frequency.
4. Zymax strings preferred, due to its wonderful tension retention property. But if other strings used, please specify how long since being strung.
I’ll start off with:
ZM62, 23x24 lbs, 1135 Hz, 2 weeks
ZM62, 22x23 lbs, 1105 Hz, 3 weeks
ZM62, 22x23 lbs, 1100 Hz, 3 weeks
ZM62, 22x23 lbs, 1085 Hz, 6 weeks
ZM65, 20x21 lbs, 1020 Hz, 2 weeks
ZM65, 19x20 lbs, 1000 Hz, 6 weeks
Please submit your data so that we all can benefit from knowing!
If there are any questions or discussions, please ask and join in.
02-27-2013, 11:24 PM #2
What a useful & informative thread.
Perhaps, we could also include the name of the racket, since racket head shape & number of string holes in the racket do matter. Additionally, i think it is useful to list down number of usage hours and playing characteristic whether smasher at the back or controller at the front for MD. The X factor would be the quality of the game the racket being used, weather & shuttle quality & type also play some part too.
We could also measure our stringer ability versus the other stringers in the other parts of the world, by comparing the frequency, the stringer claimed tension, the tension lost rate, and number of quality hours the racket being used.
Last edited by Licin; 02-27-2013 at 11:30 PM.
02-27-2013, 11:53 PM #3
^^ Re racket head shape and string density, you didn't read my OP carefully...
Also, number of grommets doesn't matter.
Yes, agree on the amount of time played and player characteristic, whether hard hitter or not... which affects the rate of tension loss.
But yep, it's interesting to note that some people claiming to play with zm62 at 26 lbs get a frequency of only 1100 Hz after a few weeks of play. This correlates to only 23 lbs from my experience.
02-28-2013, 12:48 AM #4
Therefore, i am thinking that mentioning racket name is necessary since VTZF & ordinary Iso head racket will not indicate same frequency given same stringer, tension, stringing machine, and type of string.
02-28-2013, 12:56 AM #5
I used to record the frequency of each of string job s. I had a thread with a graph drawn. Let me dig it out when I go home.
02-28-2013, 01:07 AM #6
02-28-2013, 03:20 AM #7
Interesting... I dug up one of your graphs from 2 years ago from this thread
where you measured one single length of zm62.
The data correlates directly with my frequency data on the whole stringbed!
Last edited by visor; 02-28-2013 at 03:31 AM.
02-28-2013, 07:24 AM #8
02-28-2013, 07:32 AM #9
02-28-2013, 07:52 AM #10
02-28-2013, 12:30 PM #11Originally Posted by MarkA 047667
demolidor . I had forgotten about that thread.
Google also shows these java aplets that run in windows explorer.
03-01-2013, 07:40 AM #12
Frequency also depends on frame size. Though it can be hard to tell, it definitely makes a difference.
It would also be interesting to see frequency differences due to different string patterns, on the same type of racquet
Last edited by zombie0517; 03-01-2013 at 07:43 AM.
03-01-2013, 09:32 AM #13
03-01-2013, 11:37 AM #14
Yep, frame size affects frequency probably due to a change in string density. So vztf,
z slash, cabs will ping about 30-50 Hz higher, wheras
bs series (with slight pinching in at 2 and 10 o'clock) ping the same.
2 knot vs 4 knot stringing doesn't affect the frequency, from what i've
Last edited by visor; 03-01-2013 at 11:40 AM.
03-01-2013, 04:28 PM #15
MX80 with @26lbs = 1143 Hz
AT900 LCW with @26lbs = 1129 Hz
AT700 with @26lbs = 1127 Hz
Some data from that RacquetTune thread.
03-01-2013, 04:32 PM #16
Yonex VT80 w/ BG80 @ 27lbs = 1270 Hz
Victor MX80 w/ VS850 @ 27lbs = 1246 Hz
03-01-2013, 04:33 PM #17
Yonex VT80LTD w/ BG66UM @ 27lbs = 1315Hz