**Stringway – information – Questions – answers**

Tension accuracy / actual tension
I was led to believe that the accuracy of the string job was never going to be just perfect that is if you want 60 chances are you would not get 60 across the whole bed of strings …………………………………………
We became questions from a new stringer this week about the actual tension in the stringbed.
So hereby a little more information about that:
In general:
- The tension in the crosses is lower than the set reference tension because of the frictions between mains and crosses.
- The tensions in the mains can be higher than the set tensions because these are tensioned additional by the cross strings.

Furthermore there are a lot of reasons for loss of tension:
Caused by stringer faults:
- When the string is clamped before all the elongation is removed from the string.
- When the cross strings are not lined out while the tension unit is pulling.

Caused by “machine faults”:
- When the string slips through the clamp.
- Machines with bad or no constant pull action cause a lot of loss of tension when the stringer pulls tension too quickly.
- Because the clamps move back (drawback) when they take over the tension from the tension unit.

Other reasons:

- When the string is pulled at an angle through the grommet.
- The friction between mains and crosses cause considerable loss of tension in the crosses. The same friction that is felt when pulling the string through also causes loss of tension.
The more crosses are tensioned already the higher the loss in the next string.
This loss can easily be 10 lbs or more in the last crosses.
- Slow elongation in the string causes loss of tension especially in strings with a lot of remaining elongation.
- With strings with too much remaining elongation and too low “Quality index”.
 

villis

New User
To obtain the minimum deformation of the racquet it is important to choose the right tensions for mains and crosses. You can use our online Tension Advisor for this.
If racquet manufacturer states the recommended tension which is the same for mains and crosses, how in your opinion this relates to the Tension Advisor result which gives different tension for mains and crosses? I am asking this because I hope you have had some chance to discuss this with racquet manufacturers.

I assume that manufacturers have tried to string their racquets with their recommended tension at least once, and found it good? So it means if the racquet changes shape, it must be by design? I cannot imagine manufacturers didn't have a clue of what they are recommending. Is there even any other option?
Thanks.
 
If racquet manufacturer states the recommended tension which is the same for mains and crosses, how in your opinion this relates to the Tension Advisor result which gives different tension for mains and crosses? I am asking this because I hope you have had some chance to discuss this with racquet manufacturers.
Yes we had discussions with manufacturers about the differencea between our advise and theirs. We never received satisfying answers.

Most impressive issue was the switch from 16x19 to 18x16 by one famous manufacturer.
They advised the same tension for mains and crosses for both racquets.
Our system advises 6 to 8 kg more on the crosses.
We sent them an email ……………………… never got an answer.

On the Dutch forum this matter was discussed circumstantially.
The guy who started the dscussion did exactly what TA advised 8 kg more on the crosses. The racquet came out without any change of shape.

https://www.stringforum.net/board/showthread.php?t=18684
(you can click on the translation button to read it in English)

I assume that manufacturers have tried to string their racquets with their recommended tension at least once, and found it good? So it means if the racquet changes shape, it must be by design? I cannot imagine manufacturers didn't have a clue of what they are recommending. Is there even any other option?
As you can understand based on the text above I doubt this.

Otherwise:
Our Tension advisor is in use since 1989.
We always advise the users to compare Length and width of the racquet before and after stringing. If that is ok the stress in the racquet is minimum so the Tensions were right.

We seldom get complaints about this.
 

villis

New User
Interesting. My old 18x20 Head Prestiges and PT57's recommend same tension in mains and crosses, your Tension advisor does almost the same, and I do not experience any obvious frame deformations after stringing.
I have to think that those were more properly designed than some of more modern racquets. Thanks.
 
Interesting. My old 18x20 Head Prestiges and PT57's recommend same tension in mains and crosses, your Tension advisor does almost the same, and I do not experience any obvious frame deformations after stringing.
I have to think that those were more properly designed than some of more modern racquets. Thanks.
Most modern racquets are nice ovals so the difference from the TA comes mainly from the difference in string pattern:

This is the basis for the calculations:
The main strings cause a certain widening and the cross strings have to pull this back to zero.
It is easier for 19 crosses to compensate for the widening of 16 mains than for 16 crosses for 18 mains.
That is why the 16 crosses need so much more tension per string.
 

Irvin

Talk Tennis Guru
Most modern racquets are nice ovals so the difference from the TA comes mainly from the difference in string pattern:
Not sure I understand. When I think of string patterns I think 16x16, 16x18, 16x19, etc... so a pattern identifies both the mains and crosses. No matter what the pattern is I’ve found the tension for a specific length and DT for all 16 main patterns is the same. Also the the tension for a specific width and DT for all 19 cross patterns is the same. For example the main tension for a 16 main racket with 32 cm length, and DT 34, is 24.3 kg or 53.6 lbs no matter how many crosses there are. Also the tension for 20 crosses with a racket width of 24 cm, and DT 34 is 21.8 kg or 48.1 lbs no matter how many mains there are.
 

villis

New User
The main strings cause a certain widening and the cross strings have to pull this back to zero.
This appears to be a problem. If pulling several mains causes racquet to widen (means shorten, which is supported by stringer measurements and this shortening is relatively significant), then the next main will be pulled at shorter length and it will have more tension than the main that was pulled first.
How do you deal with this, if at all?
 
This is all in the process.
The difference in tension in strings next to each other will average out.
If you would measure the actual tensions in all the strings in the racquet you will see that only very view are on the tension set by the tensioner.
Cross stringers loose tension because of the friction with the mains.
Main strings win tension because the crosses tension them more.
And all strings which are pulled under an angle will loose tension.

So the important things in stringing are:
- To maintain the shape of the racquet head,
- To obtain the string bed stiffness that the player wants.
 
Tension accuracy / actual tension


So hereby a little more information about that:
In general:
- The tension in the crosses is lower than the set reference tension because of the frictions between mains and crosses.
- The tensions in the mains can be higher than the set tensions because these are tensioned additional by the cross strings.

Furthermore there are a lot of reasons for loss of tension:
Caused by stringer faults:
- When the string is clamped before all the elongation is removed from the string.
- When the cross strings are not lined out while the tension unit is pulling.

Caused by “machine faults”:
- When the string slips through the clamp.
- Machines with bad or no constant pull action cause a lot of loss of tension when the stringer pulls tension too quickly.
- Because the clamps move back (drawback) when they take over the tension from the tension unit.

Other reasons:
- When the string is pulled at an angle through the grommet.
- The friction between mains and crosses cause considerable loss of tension in the crosses. The same friction that is felt when pulling the string through also causes loss of tension.
The more crosses are tensioned already the higher the loss in the next string.
This loss can easily be 10 lbs or more in the last crosses.
- Slow elongation in the string causes loss of tension especially in strings with a lot of remaining elongation.
- With strings with too much remaining elongation and too low “Quality index”.
loved this
great help for someone like me who just started and is practicing
 
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