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Old 02-02-2012, 02:41 PM   #2583
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Originally Posted by retrograde View Post
Based on what I know about Racquettune's algorithm, if the same string factor is used for all the measurements on a racquet, the tension loss reported should be pretty good. The absolute readings may not be spot on though.

As a double-check for tension loss, try this ... Let's say one day RT tells you the frequency is f1. A week later, tension drops and RT says the frequency is a lower number, f2. The percentage of tension retained should be the square of f2/f1. In other words, the tension is now (f2/f1) * (f2/f1) * 100 percent of what it was when you measured f1.

When you do it this way, the string density is not a factor because it divides itself out in the equations RT uses. I'd be interested to see how well my theory holds water.
Originally Posted by JT_2eighty View Post
This is just due to the difference between reference tension, "string my racquet at 58 lbs", and actual tension: no string job will ever be at the reference tension as soon as it is strung.

Even gut, known to be the best at holding tension, will not be actually at 58 lbs even minutes after it had been strung at 58 lbs.

Although, I'm not disagreeing with you that multis do lose tension and their liveliness can surely be attributed to that tension loss as well as to their elastic nature.

Sorry, not trying to be a corrective nerd or anything, but many times people confuse a reference tension (what we string the racquet at) to its actual tension (the tension we play the strings at). I think most strings lose 7-15% of initial reference tension as soon as the knots are tied (or even before the stringing is complete). But this doesn't mean you need to compensate for this and ask your stringer to string at 70 lbs so you can play it at an actual 58. The reference tension is more important, in my opinion, because that's what we can control: the starting point, and determine if that starting point allowed for a good playing experience for a long enough duration to fit your needs.

Anyhow, I'm done derailing threads for today.
Hey guys, I'm not stupid. I have 2 graduate degrees and a scientific and business background. I know the difference between relative and absolute and took advanced calculus, physics, and chemistry in college, so you don't have to explain relative percentages to me.

I already said I don't have a stringing machine, so I don't have a fresh measurement. I can only guess. When I look at these measurements, the one that's important to me is how much relative tension I'm losing after the string has settled. That's why I only reported relative loss after settling in the past when I posted on this subject. In this particular case, the string has been settling for a long time, and it keeps losing tension one week after it was strung without touching a tennis ball, which is an interesting observation. It's probably not the only string that does that. I'm not some idiot who doesn't understand why string factors affect measurements.

Last edited by Ramon : 02-02-2012 at 02:43 PM.
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