String movement

sion · 2005-04-11, 21:55

Why is it some string has lots of movement in it. Just strung my stick at 62lbs (max65lbs) 16x18 string pattern and after a few shots it was all over the place. Is there any way to stop this or is it one of those things.

Jens · 2005-04-11, 22:55

Well, every string moves with every shot. The difference between strings being "all over the place" and strings that doesn't seem to slide is in the surface of the string. If a string has a very smooth surface, the friction on the other strings is low, and the tension in the string forces it back into its original (straight) position. If a string's surface is rough (that's possible even it seems smooth), the friction is higher than the straightening force, so the strings stay crooked up after the shot. Additionally, the smaller the tension in the string, the smaller the straightening force. So often when a string loses much of its tension, plus the surface gets rough, strings start to "move".
What can you do about it? Try stringing the crosses 4 lbs tighter than the mains, you will have less string movement because the tension in the crosses forces the mains into place. Another possibility is to use string savers, but they will negatively affect the feel of the string bed.

sion · 2005-04-11, 23:07

Thanks for the explanation Joe thats a great help. I will try that on my next restring.

Salad · 2005-06-06, 04:25

Hi Joe,

I hope more people read your message. It is a general saying -- some strings DON'T move and some strings move. In fact, all strings move but some RETURN to it normal position and some NOT.

M0rgan77 · 2005-07-10, 06:09

I have played with 2 Luxilon strings, original and timo 18. I am currently using original and it stays in nice straight lines all the time. I played the timo with gut in the crosses. I,again, noticed hardly any change in the position of the string. The timo was really thin so i figured it would cut right through the gut. I decided to use string savers after i saw it start to wear a bit. It still felt really nice but it increased the tension of the strings quite a bit. I really didn't mind playing with string savers in the gut.

Jay Cee · 2005-07-10, 10:12

Quote:

Hi Joe,
I hope more people read your message. It is a general saying -- some strings DON'T move and some strings move. In fact, all strings move but some RETURN to it normal position and some NOT.

Hey Salad,
That sums it up nicely, very true indeed. but sometimes strings do not move, the higher the tension the lower the movement and the harder the string bed, not only because of the increased tension, but also because of the lack of lateral movement of the mains.

@ M0rgan77
By putting in string-savers, the impression is that the tension has been increased, which may well be the case, but the relative hardness of the stringbed is mostly due to the reduced movement of the main strings.

One of the key factors in putting spin on the ball is the capacity of the strings to "bite" the ball, a rough surface can help a little, but not as much as a smooth surface with a very low coefficient of friction between the strings (the strings spread out under the pressure of the impact of the ball) combined with a relatively high coefficient of friction between the ball felt and the surface of the strings. String-savers can seriously reduce this effect, so apart from the fact that they increase string life, they can also reduce the playability of the strings.

All depends on what you put the most importance, Pete used string-savers all the time, yet his strings didn't last very long and he sure as hell played a mean game of tennis.

JC

Salad · 2005-07-10, 22:44

Hi Jay Cee,

Upon the context of the general saying "some kinds (brand, models) of string don't move and some kinds of string move", my stand point was - all kinds of string move.

You are right that sometimes strings do not move, based on conditions. For example, a spinless ball hits perpendicularly onto the stringbed, then the string which is struck by the nose of the ball, does not move.

Salad · 2005-07-14, 23:05

Quote:

By putting in string-savers, the impression is that the tension has been increased, which may well be the case, but the relative hardness of the stringbed is mostly due to the reduced movement of the main strings.

Hi JC,

I did a rough calculations, the % increment of stringbed stiffness neither adding string savers nor string movement, exceed 0.5%. Therefore, I would like to say, the tension increase in both cases are negligible. The derivation is lengthy, full of mathematical symbols and there are some pictures, so I won't put it here. If you are interested, I can send a copy to you.

Jay Cee · 2005-07-14, 23:55

Sure Salad, why not. Send me a copy I will see if I can understand it.
I personally don't get the impression that there is an increase in tension, but the surface is somewhat stiffer, and I believe that the stiff feeling is caused by the relative lack of lateral movement by the main strings.

From the results of very extensive player tests, we always get more positive feedback for both comfort and capacity to put spin on the ball when the strings are very slippery between themselves, but with no lub-oil or silicone on the surface of the strings (comfort is OK but it's hard to control and hard to put spin on the ball.

Strangely enough the majority of strings, whether they be polys, multis or natural gut, continue to be lubrified with oils or silicone. Makes them easier to put into a racquet, but it is quite poor for playability for the first hour or two. There again the big distributors will be inclined to say that the sell string to stringers (not to players) so it's better to keep the stringers happy . . .

Maybe that will give you something to to work on, I'm not convinced that you will come up with an equation, but in practice, that's what happens.
JC

Salad · 2005-07-15, 11:19

Hi Jay Cee,

I have emailed you my derivation with the subject : String Movement.
Wish you enjoy it.

If anyone is interested too, tell me.