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What do terms “poly” and “copoly” really mean?

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For those who have been following us for years, you may have made use of our “Racquety-Yak” Message Board.  With the advent of the “Racquety-Yak” Blog, we have found discussion board participation declining, even though views have increased.  In a decision designed to better serve the needs of our users by consolidating information and also to reduce our costs we have decided to close the message board and use the blog and our Facebook Fan Page (opening soon) to respond to customer questions.

We will begin answering questions with one posed yesterday. 

Q: I’ve been looking around the web but haven’t found the answer to this: what exactly is a co-poly and how does it differ from a poly? I’ve been experimenting with polys (wilson enduro 16 and 17 and pro hurricane 15L) in my roddick+ and they’re bothering my arm a bit. I’m giving good consideration to switching to a hybrid, but I’m overseas and string selection isn’t great, though at times I can get people to bring me strings from US.

I’m trying to make it affordable and convenient. My first choice is finding a poly (or co-poly) I can use without arm problems, but I’m feeling like that’s unlikely. My second choice is a reel of poly/co-poly and a reel of something else for the crosses. Any recommendations on decent affordable options available in reels or non-pricey packages? Possible to keep the string costs below $10 per job?

A: Thank you for your excellent question!  There is a great deal of confusion with the terms “poly” and “co-poly.”  We will do our best to untangle some of this for you.

Many years ago string manufacturers found that POLYESTER was a material that offered a great deal of durability and control in tennis strings.  Early POLYESTER strings were extremely stiff, lost tension rapidly and did not really develop much of a following.  These strings were referred to as “POLY” strings.  In the 1990’s manufactures began reducing the amount of actual polyester used in the string and began blending them with different chemicals and elements.  The result was more comfortable playing strings that held playing properties longer.  When the percentage of actual polyester decreased many, myself included, began referring to these strings as “Co-Polys.”  The thought was to designate it as having more elements than just polyester so the customers would recognize that it was not the same as the old “Poly” strings.

While the thought made sense, it failed to take into account that synthetic gut string manufacturers sometimes used the term “co-poly” to describe the core and other parts of their strings.  When used in the context of synthetic gut strings the term “co-poly” does not refer to polyester, but rather polymers which are generally not the same and may not consist of polyester.  The use of the term “co-poly” in two entirely different contexts began to get confusing.  Afterall when a synthetic gut string with copoly core was being described, what would consumers think?  Would they believe the core was polyester based and thus stiffer and more durable, or would they know it was a term used to blanket the use of multiple polymers?  Add to this confusion of manufacturers actually adding polyester blends into the synthetic and welcome to “Camp Confusion!”

To put and end to this confusion we have changed our terminology.  We were the first to do so and are hoping our naming convention makes sense and catches on.  We have noticed some in the tennis world using our terminology and we are proud to have made this contribution to clearing up some of the confusion.

The term we now use for strings that are composed of polyester blended with other elements is “POLY-BASED.” This serves to let the consumer know that the string does have a polyester base.  We think it makes sense for these strings to have their own reference name, rather than sharing the term “co-poly” with polymers…that’s just too confusing.

Now, as far as your situation, the poly-based strings you are using in your Pure Drive Roddick are problematic.  The racquet itself is not very arm friendly, being so stiff and light.  Couple that with POLY-BASED strings with a high % of polyester and the arm pain is no surprise.  Some of the new poly-based strings use a lower percentage of polyester and are indeed much more comfortable.  There are a number of great options out there.  Our favorites are described on our web site.  The poly-based strings we carry are ALL softer and better playing than the ones you have been using.

You can try a softer poly-based string in a full set-up and see how your arm does.  While they are softer than what you have used, they may not be soft enough in the context of Pure Drive Roddick.  In that case we would strongly suggest a hybrid.  Use one of the newer and more technologically advanced strings in your mains at a low tension and cross it with a soft synthetic gut (something like Forten Sweet or WeissCANNON SuperString) and you will likely find a combination that offers much better playability and performance at a cost of well under $10.00 per stringing.

Good luck!

2 thoughts on “What do terms “poly” and “copoly” really mean?

  1. Drew Kilbourne on said:

    I am sorry if this comment is misplaced. I have been trying to find out how to ask a “new question” and cannot find the link. So here goes.

    I have been demoing new rackets over the past few weeks and have a question about racket flex and string tension. First I grew up playing competitive tennis and played at least 3-5 times per week in my youth with a Dunlop Maxply. Since then, I pick up the game about every 10 years and play for about 5 years at a time. I am now 48. So I currently do not have a racket I would consider “my racket.” 10 years ago I played with a Wilson Hyper hammer 5.1, which sucks. So when I recently started back I started seriously demoing rackets. In the last 3 weeks I have demoed 4 rackets per week and each played about 6 hours of tennis) mostly Friday-Sunday). I have played with the following rackets:

    Manufacturer Racket Headsize Strung Weight Swing Weight Balance Flex
    Wilson KsixOne Team Mid+ 95 10.9 325 1 pt HL 59
    Wilson Hyper Hammer 5.3 95 Stretch 95 9 301 8 pts HH 70
    Babolat Drive Z Lite 100 9.8 312 6 pts HH 67
    Babolat XS 102 Mid+ 102 10 322 4 pts HH 66
    Babolat Aero Strike Mid+ 100 10.2 314 2 pts HH 61
    Babolat Pure Storm 98 10.9 312 3 pts HL 62
    Wilson Kpro Team FX 100 10.4 307 1 pt HL 66
    Babolat AeroPro Drive Cortex 100 11.3 324 5 pts HL 67
    Head MicroGel radical Team 102 10.7 311 1 pt HL 60
    Wilson K Tour Team FX 102 10.3 315 1 pt HL 62

    Out of these rackets I only like 2 Babolats – The Aero Strike and the Aeropro drive both with cortex. Both of these rackets play insanely well compared to the rest I have tried. I seem to play better with rackets that more “player rackets.” Anything designed to give an edge goes way long and no control. The only Wilson I liked was the KsixOne team but it did not give the pop that the Babolats did.

    The Aerpro Drive crushes topsin shots that land at the service line and die. I can work any angle in the court from side to side and front to back. I can also hit shots that come in low or high and play them where I want them to go. The Aero Strike is almost as nice on my forehand but does not produce as much topspin. High Balls are hard to handle with this racket. I also tend to hit this racket very deep and sometimes long. It does play slightly better on my backhand which is nice and I am consistent with it. For medium pace shots this plays well but if someone is driving pace this racket does not handle it as well as the Aeropro Drive (not sure I need to worry given I will be playing in the 50 and up crowd in 1 ½ years).

    No for the meat of my question, I am starting to feel a little arm pain and do not know if it is because I have been hitting 2000-3000 balls per weekend or is it one of the rackets. I have also demoed a ton of rackets that had heavy vibration although I recognized that quickly and stopped playing them. There is a slightly more vibration on the AeroPro Drive (67 flex) than the Aero Strike (61 flex). Because of the arm pain I am wondering if the AeroPro is too stiff. My estimated setup for these 2 rackets would be as follows:

    I will play gut in either. I grew up on gut and just love it. That and it is better for the arm so I see it as 2 wins.

    AeroPro Drive w/Cortex (flex 67). I hit this racket short so I would string it 2 lbs light of mid tension in the range. That would give me a tad more distance and should also reduce some vibration.

    Aero Strike w/Cortex (flex 61). I tend to hit this racket long and if I am not paying attention balls will just fly to the fence. If I am concentrating hard and add a little more whip on my forehand I can control it well in the court, but cannot generate the topspin of the Aeropro Drive. So I am thinking this needs to be strung about 2 lbs heavy of the mid range to slow down the ball and add some control. This will however, increase the vibrations from the racket.

    So my dilemma is if I get the stiffer racket and string it softer or the more flexible racket and string it harder are they becoming the same in terms of arm health. Or am I over thinking this and my arm is just hurting because I have playing some much, so quickly after a 10 year hiatus.

    I am sorry for the long post but would really like some help. I have found many posts about the Babolat Pure Drive and arm problems but none on the Aeropro and no reviews at all on the Aero Strike, So I am looking for some advice.



  2. ggtennis on said:

    @Drew. Questions are typically asked via email, though this will work as well.

    There is a lot going on in your post. First we applaud you for taking the time to find a good and arm healthy racquet. While we can not provide you with a specific recommendation we are happy to share our thoughts on the topic.

    There is no way to tell from the post what the core cause of the pain is. It could be the amount of play. It may very well be the equipment. We do not know what strings were in the demo racquets, and this can make a difference.

    In terms of the two Babolat sticks…assuming they were not strung with natural gut, It sounds as if you are more comfortable and confident with the Aeropro Drive. Babolat racquets are stiff and for many, hard to control. If balls were flying with the Strike, I would suspect you would see more of the same with natty gut. Unfortunately I fear the Aeropro Drive may also be harder to tame with a full natural gut setup. Babolat sticks have earned the nickname “back a lot” because of the control issues many experience with them. We do not have any experience with the strike, but many of our local stringing customers use the AeroDrive. Some of them have developed arm/elbow issues and switched racquets while some have experienced no such problems. The racquet is definitely not the most arm healthy, but used with natural gut, it may work for you. We would suggest buying a used one (less initial investment) and stringing it up with natural gut. Play with it using the gut and see if it is what you expected. If so, go ahead and invest in a new one. If not, resell the used racquet and you will not be out too much. It will be like an extended demo for you.

    We would also suggest the following demos:

    Dunlop Aerogel 200
    Fischer Mpro 1
    Yonex RDis 300
    Adidas Response
    Wilson kblade team

    The above demos are recommended because we are not convinced that either of the final two Babolats are as arm-friendly as you are seeking. Some of the above may provide similar play with better arm health prospects.

    Best wishes!


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