RacquetTune way off?
 

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.

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

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.

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

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

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

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.

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

Could you clarify what you mean by "measure the string?"

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.

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?

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.

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.

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.

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.

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).

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...ctor_2012.html

Holy smokes....that tension loss chart is eye opening.

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))?

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?" :)