Jon Levey answers your equipment questions in Gear Q&A. Click here to submit your question.
I’ve decided to experiment with various polyester strings, and my stringer warned me not to play for too long with one string job. He said the strings become “dead” and there’s a danger of arm problems. Is this true? Thanks.—Doug P.
That’s nonsense. Sounds like your stringer is just looking for lots of repeat business. Actually, I’m just kidding—he’s obviously pretty knowledgeable about polyester strings and is looking out for one of his customers. I’m by no means a string expert, but since I have done my fair share of playing with and researching poly and co-poly strings over the past dozen years, I’ll do my best to sum up the “dead” issue, which is very much alive and problematic for many of its users.
An irony of poly strings is that one of its greatest attributes—its durability—should actually rarely, if ever, be put to the ultimate test. Professionals champion polys, but they don’t keep a string job for longer than a few practices or a match; the real finicky ones don’t go longer than a ball change. Since they never use a string until it's remotely close to breaking, the enhanced longevity of polys is completely lost on them. They generally employ polys for two other desirable reasons.
First, the inherent stiffness of the strings offers a greater degree of control. It’s firmness deforms the ball more than softer strings, resulting in a loss of energy. This means players can swing harder with less worry that the ball will be difficult to keep between the lines. To detractors who prefer lively strings, polys actually feel dead right from the start. And the rigidity, coupled with the swing speed needed to create adequate pace, can lead to arm issues.
The other property players covet is the string “snap back” that results in added spin. All strings move at contact, but polys are less abrasive and slide back faster and more frequently for elevated spin production. And since you can swing all-out, this promotes even greater spin generation.
The problem for poly users is that the strings tend to lose tension and playability quicker than most other synthetics. The amount of time it takes will vary depending on the string, player, and playing style. One hour of playing time for a topspin-happy baseline grinder will age strings much quicker than a serve-and-volley doubles specialist. So simply going by a set time or number of sets played is often not constructive. It’s going to be an individual discovery; it could be as few as two sets, or as many as 20. There’s also the possibility that, depending on the type of poly used, it could break before it ever reaches its expiration date.
So what happens when a polyester string does go “dead”?
It’s not an exact science and players often differ on what “dead” means to them. Basically, as the strings repeatedly contact the ball, their tension and stiffness drop. The strings start breaking down and actually become softer and more powerful, which to some results in a rather mushy string bed. It may in fact feel more comfortable at this point, but the control aspect is greatly diminished. The ball stays on the strings longer, and the added dwell time creates more opportunities to send shots long or wide.
During this time the friction between the mains and cross strings also increases. Essentially, the strings become more abrasive. This means less sliding back into position and a reduced snap back. This bunching of the mains can also increase tension on the crosses and why some people conversely believe that dead polyester strings feel boardy, rather than mushy; again, it’s in the eye of the (racquet) beholder. It’s more difficult to generate spin and the launch angle is lowered, so players compensate by swinging more violently to capture previous results.
(One of the more common analogies to describe a poly—as one of our testers, Max Callahan pointed out—is to that of a spring. When a spring is stretched to appropriate lengths, it snaps back and keeps its form and characteristics. However, when stretched too far it remains straight and ceases to act like a spring. So it goes for a poly that deforms with repeated use, and loses what makes it useful.)
This is where players can also run into some arm troubles. The cumulative effect of repeated aggressive swings—often with stiff frames laced with “dead” polys that don’t absorb much energy—can take its toll on wrists, elbows, and shoulders. And since polys are so durable, the strings can be in this state for quite a while before finally breaking.
That’s why it’s often recommended to cut out the strings long before they actually break, and ideally as soon as they start to lose their playability. A telltale sign that you’ve waited way too long to restring is if you cut a main string and it slowly gives way rather than snaps with a distinct popping sound. Personally, I use the string movement as a barometer: Once I find myself needing to readjust and straighten the strings between points—which is usually around the time I start to notice a change in the shape of my shots—I know my strings are finished.
Good luck in search and remember: While it feels satisfying to snap a string, you’re always better off cutting out a poly too early, instead of too late.