Stringing: The Dead Zone
What happens to tennis strings with time and use? And how can you help your customers determine when it is time to restring?
Tennis strings go dead … Or do they?
According to Rod Cross and Crawford Lindsey in the book Technical Tennis (Racquet Tech Publishing, 2005), strings do not go dead in the racquet.
“When a string loses tension, it becomes softer,” they write. “That is all that changes in a string. It does not lose power, resiliency or ‘go dead’ in any quantitative way. It simply becomes less stiff, and thus feels ‘different’ to the player.”
But players describe that difference in many different, and often conflicting, ways. Some describe balls flying off the racquet with a loss of control, while others describe a soft, dead feeling that lacks power.
So, what happens to strings with time and use? If strings don’t go dead, what is it that changes, and why do players have a hard time agreeing on just what that difference feels like?
We set out to find an answer and were led right back to our old friend and string expert Crawford Lindsey. It seems that Lindsey was curious also, and in his usual way set out to conduct tests to find the answer. His results can be found in a two-part article on the Tennis Warehouse University website.
What Actually Happens
Basically, Lindsey found two significant changes that occur.
First, the strings relax internally and lose tension. This involves relaxation at a molecular level and does not show up as a string stretching and getting longer over time. (I have several racquets in my collection that date back to the 1920s, and many were last strung 80 years ago or more, yet the string beds are relatively firm. They may disintegrate if they were to hit a ball, but they are not sagging in the racquet.)
But what does happen is the strings become less stiff. When this happens, at impact the ball imbeds deeper into the string bed and stays there a fraction of a second longer, before being sent off at a higher trajectory than usual. The ball then travels farther and is usually perceived by the player as having more power and a loss of control.
Second, as strings wear, they get roughed up and no longer slide against each other as easily. With gut and multifilaments, the outer fibers break and wear, making the coating rougher and less likely to slide. Monofilaments and single-wrap nylons will actually notch and are difficult to move at all.
With a fresh string job, if you move the main strings with your fingers, they will more or less snap back into position when released. But after being in the racquet for a while and especially with some hours of play on them, the strings will stay where they are moved. With the current designs of racquets and strings emphasizing spin, you will see a lot of information about how string “snap back” plays a significant role in generating spin. So when this snap back is hampered, it will have a negative impact on performance.
Both of these changes that occur — tension loss and friction increase — happen to every string regardless of the string’s composition or the tension at which it is installed. Each string and situation is unique and the changes will occur at differing rates depending on the string and the playing style of the player. One string may lose tension quickly but maintain its ability to slide, which will make it feel like it gains power and loses control. Another string may hold tension better but begin to stick to itself more, resulting in less spin and power, and making the strings feel dead.
Lindsey sums things up: “The strings are simultaneously gaining and losing in power behaviors or in stiffness and softness characteristics. It is the net effect that determines the player’s perception of string performance.”
When to restring, then, really depends on the perception of the player and his or her sensitivity to the changes that occur. Many top pros go to a fresh string job with every ball change (every nine games) in a match. Obviously, they are very sensitive to change. As the balls get fluffed up and their strings lose tension, they can feel the difference, no matter how slight.
So, does your level of expertise on the court determine your perception to change in the string? Not necessarily. Although many of the top pros change to fresh racquets often during a match, others prefer to stick with one as long as possible.
During his professional career, James Blake rarely had more than two racquets strung before a match and often played the entire match without ever changing racquets, so it really depends on the player and their perception of the change to determine when a restring is called for.
But, regardless of sensitivity, the strings will need to be replaced at some point. For some it may be once a season; for others, much more often. It is up to us as racquet technicians to help players determine what their comfort zone is and when it is time to restring. While this is mostly determined by the player, you can certainly help them by being able to quantify what they are feeling.
We’ve determined that the change in a player’s strings is very subtle and happens in small increments with every impact of the ball and over time, which makes it difficult for most of us to determine when it is time to restring. The old adage of “restring as often in a year as you play each week” is no longer valid, if it ever was. One player may hit 100 balls in a session while another may hit 1,000 during the same time frame.
An even bigger factor in the equation is the string itself. Today’s strings vary so much in their composition, stiffness, thickness, coating and ability to retain tension, there is really no way to assign an expiration date to a string job. It is really dependent on the racquet, string and the player’s sensitivity to determine how often to restring. But, as professional racquet stringers, we should be educating and advising our players. So how do we do this?
You need to know your clients. Ask questions and listen to them to find out as much as you can about how they play and what they feel is important. This holds true for helping them determine not only when to restring, but also in selecting the right racquet, string and tension.
I often will have a player tell me they really liked the racquet after it had a few hours of play. This tells me that dropping their tension just a bit will give them that same feel from the start.
An essential tool in helping your clients determine their comfort zone is by tracking the string-bed stiffness or dynamic tension. This will make your job easier because it can quantify the difference the player is feeling, which will most likely translate into the player restringing more frequently.
Using A Diagnostic Tool
If you want to see a dramatic jump in your business, incorporating free string-bed testing will do the trick. Once your customers understand what you are doing, their frequency of restringing will increase — and you’ll see new customers coming through your door.
String diagnostics tools come in many forms, from large multi-tasking units like the Babolat Racquet Diagnostic Center (RDC) to small hand-held units. They also use a variety of methods to read the string bed. The RDC and some others actually depress the center of the string bed and provide a reading. Others use harmonics by vibrating the string, while others twist and measure the stiffness of one string at a time.
When servicing your players, what’s important — no matter what diagnostic tool you may use, and whatever type of “number” that tool generates — is the percentage drop over time.
Also, whatever diagnostic tool you use, you will need to be consistent as to how it is used, when measurements are made, and where it is placed on the racquet — to make sure you are comparing apples to apples.
The best thing is to test the string job right after you take it off of the machine. This will be your baseline. When you test later on, the number will drop.
It is up to your client to determine their “magic number” as to when they feel they want to restring. For some players, a 15 percent drop is noticeable enough to affect their game, while others may be fine waiting until that number drops 35 percent or more. This takes the pressure off of you; the client will determine their number and will come by often for a check up.
Once the number dips below that predetermined plateau, you have another string job — most likely much sooner than you would have without the diagnostics. And importantly, you’ll also build more foot traffic in your store.
More Frequent Restringing
“We have customers coming in frequently asking, ‘How’s my strings?’” says Randy Stephenson, MRT and owner of Rackets N Strings in Plano, Texas. He’s been using the Babolat RDC since his shop opened a little over a year ago. He tests the string-bed deflection (SBD) after each restringing and records it in the customer’s file and on the sticker he places on each racquet. “It’s really simple. When a customer comes in, I don’t even have to pull their record. The original SBD is on the sticker so I can just test and compare. Now that customers know I can track loss, they are restringing more frequently.”
Philip Van Asselt, MRT and owner of Tennis Junction in Bryn Mawr, Pa., says they used to put a “restring by” date on the frame — until they added the RDC machine to their arsenal in early 2012. “Poly’s would get three months and synthetics a six-month restring date,” he says. “But now, with the RDC, players rely on the RDC number to help them decide when to restring — and often it is before it is really dead. We use the RDC to show the customer the power level of the string. I think it adds a level of professionalism and shows them that we are not making things up when we suggest a restring.”
Encouraging your customers to get in the habit of checking the status of their strings frequently is vital. When they do, they will restring when they need to, instead of waiting until the due date or later.
Matt Steverson, MRT and owner of Matt’s Tennis in Altamonte Springs, Fla., uses the ERT 300 for string tests because of its portability, even though he has a Babolat RDC. “I keep an ERT in my tennis bag and my customers know this,” he says. “They’ll come up to me on court when I am teaching or playing and ask to have their racquet checked, and it’s not unusual to get a couple of string jobs on the court.”
Steverson records the dynamic tension on every racquet he strings and also puts it on the label he places on each racquet. Even if he is not at his shop, the original dynamic tension is on the label so he can help the player determine if a restring is in order on the spot.
Restringing can be — and should be — an even bigger part of our business. It’s a matter of educating consumers and players when it is time to get rid of their old strings.
Contributing Editor Kent Oswald contributed to this story.
See all articles by Bob Patterson
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