Category Archives: Bad Stringing
In Part Un we discussed the difference between shanking (mis-hit) and friction failure. It was obvious that the string was broken. But what happens when it is not so obvious?
Part Deux, this part, will examine the frictional notching failure of monofilament string and how we can be prepared for it! To further refine this discussion we will be comparing PET polyester has PEEK monofilament string. The reason is that each material while both will notch one requires more time to reach the critical dimensional decrease that is a failure!
In almost every Racquet Quest Podcast we talk about tension v string diameter and agree that once 50% of the string diameter is notched away the string is vulnerable! So a .050 (1.27mm) diameter string that has a tensile strength of 120 pounds at 50% notching will have 60 pounds of tensile strength remaining.
This graph is a string that was broken during use. The string was removed from the racquet. The top line is the tensile strength in the area of no notching so you can see that it is pretty strong still and has stabilized due to use. That stabilization is indicated by the very tight stress/strain grouping.
However, things go sideways when the notched area of the string is put under stress. The string failed at a force of 63.8 pounds, or about 59% of the used tensile strength. Not bad!
So, notching is failure-inducing but how long it takes to create the fatal notch differs with string material. This particular set of strings had about six (6) hours of play.
In Part Trois, we will look at PEEK material under the same conditions!
We all have heard the question “which comes first the chicken or the egg”? However, my question is “Which comes first the game or the string”?
I believe they happen simultaneously. But first a quick story.
In 2005 I was attending a Head product introduction on the island of Mallorca, Spain, Yes, that one!
The product introduction was exciting but what I am going to tell you about now was even more meaningful.
The Director of one of the top US Tennis Training organizations, at that time, was there and we were discussing teaching techniques and what he said after being in this part of Europe was “we need to start teaching our players how to hit this way!” Well, “this way” was the way of low-powered strings that were popular in Europe but not so much in the US, yet.
So, it began! The players could not hit harder, like the Europeans, unless they used the same string material as the Europeans and that was very stiff and mostly PET polyester.
So, the idea was the “egg” and the string was the “chicken”, sort of! I guess the feeling was that “if Americans are going to compete we must use the same equipment”.
Now, I believe the professional game can go on about its way but otherwise, we need to consider changing the game by returning to a combination of comfort and playability.
Our history shows us that the “high performance” life span of many polyester strings is about 2-3 hours, or less, maybe about 10-12 games. We don’t believe this is quite long enough for most players. But, how do you quantify “performance”? It may be different things for different players.
There are many components to performance but what if it was associated with UTR data? Racquet Quest can track UTR numbers and make some determinations based on that data. If a UTR is stable or increasing it is a good bet that the performance of the player and equipment is OK. However, if the UTR is slipping it is a good indication that something is not working as it should…but what?
We have found that, in some cases, it is injury or discomfort, that is causing the slippage! Stop it! The following data is for a 12 month period and acquired from the UTR website. Even small positive changes are tough! But negative changes seem to have an enormous impact more quickly than positive changes!
|A||Head Speed||PEEK||12.84||12.86||+ .02|
|B||Babolat Pure Aero||Polyester||10.91||9.56||-1.35|
|C||Head Radical MPA||PEEK||4.50||5.61||+1.11|
|D||Wilson Pro Staff 97||PEEK||5.0||7.03||+2.03|
|E||Babolat Pure Aero||PEEK||3.8||5.64||+1.84|
|F||Wilson Blade 98||Polyester||10.0||9.41||-.59|
|G||Head Radical Pro||Natural Gut||3.7||5.15||+1.45|
If you have been listening to the Racquet Quest Podcast you know we have talked about what to NOT accept when you pick up your newly strung racquet.
We know it is hard to visualize sometimes so these pictures are posted to give you a visual aid! This is the very same string! One could conclude from these images that the person responsible for these knots has not had any training at all. It makes you wonder how good the rest of the string job is!
In the interest of improving all stringing, please do not accept this kind of work.
The image below shows the “dreaded” crossover! This is not only a potential string damaging error it indicates a lack of skill, or understanding, of doing a good job!
Of course, mistakes do happen but it is the responsibility of the stringer, in this case, to correct the mistake before the client comes to collect their racquet!
It sure sounds simple but is it? Not really! When talking about tennis preparedness that means having enough racquets ready for the tournament, organizing training sessions, plenty of shirts, shoes, and socks, of course!
But, what’s missing?
Your string is missing! Sure, you have done a great job of getting your racquets ready but I don’t see several sets of the string you use in the bag! Why not? You may believe they will have it at the tournament site, and, if you are using a commodity string, you may be right!
But what if you’re using a high performance string that is set up for your playing style?
- Take a few sets of your preferred string with you. I prefer sets over reels but that is up to you.
- Tell the stringer exactly what you want. That means knowing what you want so be prepared!
- Request that your racquet be strung using two (2) pieces of string and the cross strings be started at the top of the racquet. No exceptions! No ATW’s, No natural one-piece, simply two pieces top to bottom!
Know how to identify the correct stringing procedure and don’t accept anything that is not up to your standards!
Most qualified stingers will appreciate your input and do the proper job for you!
Today a racquet came in that was strung at a tournament that missed the mark! One-piece ATW, sloppy knots, distorted head shape, and a string that is not used by the player!
That is why we are posting this… “Be Prepared”
If you listen to the Racquet Quest podcasts you will recognize this statement!
So, why are we posting it on the website if it is already a podcast? Because it is serious! A racquet came in today that reminded me of why we started GASP! The stringing is so awful that I can’t keep myself from writing this!
The owner of the racquet does not remember at which tournament it was strung otherwise we could contact them and offer some suggestions!
Why is this racquet so bad?
- Inconsistent tension across the string bed
- The accuracy index is 65!
- Virtually no tension in the top cross string…because
- The racquet was strung from the bottom up plus the poor knot
- Stringing of the crosses started at the bottom (starting X at the top is highly recommended)
- Tie offs on the wrong holes
- 8M is better
- Cross over at the lower side
- Probably due to the wrong tie off
- One-piece format
- Inconsistent string tension
- Bad tie off knots
Why is it so hard to do a better job when stringing a tennis racquet? In this case, it appears the stringer has no training. There are errors no competent stringer would make! But, until players refuse to accept this shoddy work it will continue!