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Poly tension loss

Q: We are getting some complaints from customers who say that a certain poly plays really well, but loses a lot of tension in a short period of time. I strung one for myself and the string really does lose tension quickly — much more than it should be losing. I checked the USRSA string lab test data, and found that tension loss of this string is quite similar to other polys we usually string in other racquets. Can we pre-stretch this particular string to reduce tension loss? How it should be done?

A: Although strings in this class are all called “poly,” there are actually different formulations. Different formulations are likely to feel different during play, and when you factor in the built-in differences in response and feel that occur due to tension loss, it’s not surprising to find that one string seems to play better after a few days than another, seemingly comparable string. So, unless you are somehow measuring the tension loss, you have to be careful about saying that one is losing tension much more quickly than it should. If you are going by feel alone, you can be deceived by the difference in characteristics among the various formulations.

Pre-stretching will reduce tension loss, but it will also make the stringbed play more stiffly. As polys typically feel fairly stiff to begin with, this may be unacceptable to your customers. You can either pre-stretch at 45 pounds for 45 seconds, as outlined in Racquet Service Techniques, or you can use machine pre-stretch on electronic machines that offer that feature.

If either the feel or the tension loss still are not what your customers expect, you might try another poly.

From the September 2007 issue
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