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Mig1NC
01-18-2010, 09:58 AM
I had TF Black Code 17 installed in a full set in a 100sq racquet at 62-63lbs. I realize that reference tension will not be the same as practical tension after stringing.

I hit 1 hr with it against a ball machine at mid speed settings.

The next day my string meter came in and I checked it at around 58lbs on both center mains at the mid point (the stringmeter guage said it was bordeline 16g/17g so that's where I set the dial at).

So, after two more hours of playing against the ball machine and a couple of weeks since it was restrung, it still says it is around 58lbs.

I really thought it would drop off more. But it didn't.

Is my string meter right? Or am I expecting more drop off than I should be?

rosheem
01-18-2010, 02:42 PM
I just got a stringmeter as a gift and I'm seeing similar results.

I don't think you should expect to see a dramatic drop-off on each individual string. If you look at the average tension across the center 6 or 8 mains and also across the center 6 or 8 crosses, and then track it, you'll probably see a gradual drop-off that more closely reflects the gradual decline in overall stringbed stiffness. But if each individual string was measurably losing tension after every session, that would probably equate to a pretty dramatic overall tension loss.

In other words...since the stringmeter only measures each individual string, you won't see a tension loss that accurately reflects the overall loss in stringbed stiffness. Probably need to be looking at the average of a bunch of strings.

DrpShot!
01-19-2010, 08:05 AM
The way I understand it, and from my own experience, after the initial tension loss in the hours right after stringing, tension should remain fairly stable for weeks or months, depending on how much you play and the conditions you play in. Polys should remain pretty stable after a comparatively large loss of tension right after stringing, multis will remain a little more stable after intial stringing but break in more over time as the resins and bonds break down.

aksman
01-19-2010, 11:29 AM
I had TF Black Code 17 installed in a full set in a 100sq racquet at 62-63lbs. I realize that reference tension will not be the same as practical tension after stringing.

I hit 1 hr with it against a ball machine at mid speed settings.

The next day my string meter came in and I checked it at around 58lbs on both center mains at the mid point (the stringmeter guage said it was bordeline 16g/17g so that's where I set the dial at).

So, after two more hours of playing against the ball machine and a couple of weeks since it was restrung, it still says it is around 58lbs.

I really thought it would drop off more. But it didn't.

Is my string meter right? Or am I expecting more drop off than I should be?

I'm wondering the same exact thing. No string meter, but with BC 17 on a 100sq in racket, experiencing the same thing I believe.

Approximately how much tension loss is expected with these strings? And, how does that compare to other strings?

LPShanet
01-20-2010, 01:46 AM
I had TF Black Code 17 installed in a full set in a 100sq racquet at 62-63lbs. I realize that reference tension will not be the same as practical tension after stringing.

I hit 1 hr with it against a ball machine at mid speed settings.

The next day my string meter came in and I checked it at around 58lbs on both center mains at the mid point (the stringmeter guage said it was bordeline 16g/17g so that's where I set the dial at).

So, after two more hours of playing against the ball machine and a couple of weeks since it was restrung, it still says it is around 58lbs.

I really thought it would drop off more. But it didn't.

Is my string meter right? Or am I expecting more drop off than I should be?

First off, it's important to understand what exactly Stringmeter is telling you. It's not just the difference between reference tension and practical tension that's at work here. What it is NOT telling you is the "tension" at which you strung the frame. The numbers that the Stringmeter gives you are a measure of stringbed stiffness, NOT of linear tension (which is the number you set your stringing machine to). It becomes confusing sometimes, because those numbers sometimes are in a similar range, but they are totally disconnected. Don't think of the Stringmeter numbers as "pounds" in the same sense at you think of your original string tension in pounds. Stringmeter is measuring the resistance to deflection of the entire string bed. Your reference tension refers to how much weight equivalent was used to pull the string across the plane. Not the same thing at all.

So comparing your Stringmeter numbers to your original tension is no more useful than comparing meters to ounces. What you use Stringmeter to do is measure RELATIVE string bed stiffness. So, for example, if your Stringmeter number is the same in a week as it is today, then it hasn't lost any stringbed stiffness. If its original reading was 60 and it's now 54, it's lost 10%, and so on. You can only compare Stringmeter numbers to other Stringmeter numbers.

All that said, and assuming that you're measuring technique is correct, your numbers are a bit surprising, but not impossible. I'd suggest measuring again after a few more playing sessions and see what happens. If you have video capability, you might want to do a quick video of yourself using the Stringmeter, so we can check that you're doing it right. If you keep getting nothing but 58s, it may indeed be broken:)

Hope this helps.

Mig1NC
01-20-2010, 03:24 AM
Good idea. I'll try and get out and hit with that stick again while it is nice out and measure again and youtube it.

rosheem
01-21-2010, 05:39 AM
Stringmeter is measuring the resistance to deflection of the entire string bed.

What you use Stringmeter to do is measure RELATIVE string bed stiffness.



Just wanted to point out that the Stringmeter only directly measures individual strings, not the "resistance to deflection of the entire string bed." If you measure a whole bunch of strings, you can indirectly calculate an approximate relative stringbed stiffness and then monitor it over time. But the device itself only measures one string at a time.

If you are talking about measuring string bed stiffness directly, then you would be using something like the ERT 300, which uses vibration to compute the dynamic tension, which is the ball power required to depress the stringbed by 1 cm during impact.

Another useful application of the stringmeter is to measure individual string tension DURING the stringing process (if you string for yourself). Here, you are not trying to get the tension on your machine to match the value on the stringmeter....instead, you would use the stringmeter to measure the tension of strings on each side of your racquet to ensure that your technique is producing a consistent stringbed. In other words, you want your 2nd main on the right to match the 2nd main on the left. You expect the measured tension to gradually increase as you move away from the center mains, but I think you want to limit the difference between the center mains and outer mains to something like 10 percent.

LPShanet
01-23-2010, 05:06 AM
Just wanted to point out that the Stringmeter only directly measures individual strings, not the "resistance to deflection of the entire string bed." If you measure a whole bunch of strings, you can indirectly calculate an approximate relative stringbed stiffness and then monitor it over time. But the device itself only measures one string at a time.

If you are talking about measuring string bed stiffness directly, then you would be using something like the ERT 300, which uses vibration to compute the dynamic tension, which is the ball power required to depress the stringbed by 1 cm during impact.

Another useful application of the stringmeter is to measure individual string tension DURING the stringing process (if you string for yourself). Here, you are not trying to get the tension on your machine to match the value on the stringmeter....instead, you would use the stringmeter to measure the tension of strings on each side of your racquet to ensure that your technique is producing a consistent stringbed. In other words, you want your 2nd main on the right to match the 2nd main on the left. You expect the measured tension to gradually increase as you move away from the center mains, but I think you want to limit the difference between the center mains and outer mains to something like 10 percent.

All true. I was oversimplifying to express the difference between linear tension and stringbed stiffness.