Playtest: Gamma Zo Tour 16
By Greg Raven
Gamma Zo Tour is a “multifilament” polyester string that is made of six PET (polyethylene terephthalate) monofilaments surrounded by Gamma’s Zo energy core material. Gamma tells us that this unique construction gives Zo Tour a softer, more forgiving feel than other polys, without sacrificing other characteristics that have made polys so popular.

According to Gamma, Zo Tour is designed for players who prefer maximum control, a firm, ultra crisp feel, ultimate comfort, and greater durability.
Zo Tour is available in 16 gauge (1.30 mm) and 17 gauge (1.25 mm) in orange only. It is priced from $16 per set of 40 feet, and $264 for reels of 660 feet. For more information or to order, contact Gamma at 800-333-0337, or visit gammasports.com.
IN THE LAB
We tested the 16 gauge Zo Tour. The coil measured 40 feet. The diameter measured 1.31-1.33 mm prior to stringing, and 1.26-1.27 mm after stringing. We recorded a stringbed stiffness of 75 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 x 18 pattern) on a constant-pull machine.
After 24 hours (no playing), stringbed stiffness measured 65 RDC units, representing a 13 percent tension loss. Our control string, Prince Synthetic Gut Original Gold 16, measured 78 RDC units immediately after stringing and 71 RDC units after 24 hours, representing a 9 percent tension loss. Zo Tour added 18 grams to the weight of our unstrung frame.
The string was tested for five weeks by 39 USRSA playtesters, with NTRP ratings from 3.5 to 6.0. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. Average number of hours playtested was 25.9.
Zo Tour feels thick and substantial, but installation is similar to that of other polys.
One playtester broke his sample during stringing, nine reported problems with coil memory, five reported problems tying knots, and none reported friction burn.
ON THE COURT
Gamma Zo Tour did well with our playtest team, garnering four top-twenty placings of the 124 playtests we’ve published to date. The Durability rating was 11th overall, Resistance to Movement was 16th overall, and Control and Spin Potential were each 19th overall. In addition, our team scored Zo Tour well above average in Tension Retention. On the strength of these five great scores, overall Zo Tour came out well above average.
Two playtesters broke the sample during testing, one at three hours and one at 14 hours.
CONCLUSION
Even though the scores given Gamma Zo Tour by our playtest team are impressive, their comments are overwhelmingly positive. Thirty-two of 38 playtesters had great things to say about Zo Tour, with many of the observations touching on the same themes of durability, power, control, spin, and tension maintenance.
Playtester Comments
“Incredible control and spin. Impressive comfort for a polyester. Topspin players will love this as the spin seems to extra heavy. The ball comes down very hard. Big baseline swings unlock more than enough power. The harder I swing, the better it feels. Tension maintenance is great. I did not notice the typical polyester tension loss. I intend to stock this string.” 4.5 male all-court player using Babolat Pure Drive Roddick strung at 62 pounds LO (Babolat Pro Hurricane 16)
“The feel is a little stiff, but the results are hard to argue with. This is one of the best control strings I’ve used. Fast swings are extremely easy to place. I am able to hit angled passing shots with confidence. The bite makes the ball come down inside the lines. This is a keeper.” 5.0 male all-court player using Völkl DNX 10 Mid strung at 54 pounds LO (Head Synthetic Gut PPS 17)
“The combination of power and spin give this string the “wow” factor. Usually polyester goes dead fairly quickly, but this string retains its playability, feel, and pop for a long time. This is perfect for people who are tired of their string bed going dead after a week of play.” 6.0 male all-court player using Wilson KPro Tour strung at 60 pounds CP (Babolat Ballistic Polymono 16)
“This string has an incredible combination of comfort and control. I have to keep checking to make sure I’m playing with polyester. Unlike with most durability strings, compact strokes are not punished with a dead response. This is a very user-friendly string. Controlling the ball’s height and depth is a cinch.” 3.5 male serve-and-volley player using Prince O3 Red MP strung at 60 pounds LO (Gamma Live Wire XP 17)
“I did my best to break this string. No luck. String movement is very minimal. The combination of tension maintenance, comfort, power, and control make this one of the better polys on the market.” 4.5 male all-court player using Wilson nSix One Tour strung at 62 pounds LO (Kirschbaum Touch Turbo 16)
“Very easy to handle. This string is ideal for hard hitters. There is nothing like the confidence that comes with knowing you can swing out. The control is excellent.” 4.0 male baseliner with heavy spin using Dunlop M Fil 200 strung at 57 pounds CP (Babolat Pro Hurricane/Gamma Synthetic Gut 17/17)
“When needed, this string has more than enough power. I can hit every shot in the book with it. The control is simply excellent. Volleyers will love the crisp response. A controlled block delivers some nice pop. Directional control is well above average.” 5.0 male all-court player using Prince Ozone Pro Tour MP strung at 55/58 pounds LO (Prince Synthetic Gut Multifilament 16)
“This is a very lively polyester. Do not be afraid to string it at the very bottom of tension range, especially if you don’t like a boardy feel. At low tensions, it has the perfect quantities of control and power. There is no trampoline. More importantly, it is not hard on my arm like other polys. Thumbs up, way up.” 4.5 male all-court player using Völkl DNX 1 w/Power Arm strung at 48 pounds LO (Forten Dynamix 16)
“This string is not only durable, but comfortable and playable. I expected a tiny sweet spot and a lot of harsh feed back. I stand pleasantly surprised.” 5.0 male all-court player using Babolat Aerotour + strung at 56 pounds CP (Babolat Pro Hurricane/Babolat Xcel 16/16)
“What this string lacks in power, it more than makes up for in control. Tension maintenance is remarkable and string movement is nonexistent.” 4.0 male serve-and-volley player using Wilson KFour strung at 54 pounds CP (Prince Lightning XX 17)
“This poly is on the soft side. It grips the ball well. Though it is a non-resilient string, the dwell time seems very pronounced. The spin potential and control are outstanding.” 5.0 male all-court player using Wilson Pro Staff 6.0 Original MP strung at 64 pounds CP (Luxilon Big Banger Original Rough 16)
“I really like this string! It has a unique combination of durability and playability. The crisp and predictable response adds confidence to my serve and volleys.” 5.0 male all-court player using Head Liquidmetal Prestige Mid strung at 64 pounds LO (Prince Synthetic Gut Original 16)
“For the first 4 hours this string plays much better than an average polyester. The control, feel, and comfort are outstanding. After losing tension, it plays closer to its peers; however, it’s still the best polyester I’ve tried.” 4.5 male all-court player using Wilson Triad 4 MP strung at 58 pounds CP (Gamma Professional 17)
“This string starts crisp. Eventually it softens, but the control never leaves. I’m not a fan of polyester, but I really like this one. The control and power are impressive.” 4.5 male serve-and-volley player using Wilson nSix One (68 Holes) strung at 56 pounds CP (Wilson NXT 16)
“This string inspired me to hit with more topspin. The bite is phenomenal and the comfort is exceptional for the breed. It has more control than any string I’ve tested. After 26 hours, it shows no signs of wear. It I had to play with polyester, I would play with this.” 3.5 male baseliner with moderate spin using Head Metallix 2 strung at 56 pounds CP (Gamma Asterisk 16)
“This string has some nice pop. It seems to snap back hard and return extra energy to the ball. The added bite makes this a topspin weapon.” 5.5 male all-court player using Wilson nSix One Tour strung at 57 pounds LO (Ashaway Crossfire 17)
“Polyester strings have come a long way. This string is great for the advanced player looking for more durability, control and spin. It is also great for intermediates concerned with power and comfort. It has an impressive range of favorable qualities.” 6.0 male all-court player using Tecnifibre T Feel 290 XL strung at 58 pounds LO (Tecnifibre NRG2 16)
“The good control makes it easy to overlook the somewhat harsh feedback on off-center hits. This combination of bite and predictability make it ideal for players with control problems. People who like a softer response are advised to lower the tension or turn it into a hybrid with a soft cross.” 4.5 male all-court player using Head MicroGEL Prestige MP strung at 56 pounds LO (Gamma TNT2 17)
“Polyester keeps getting better. The control and spin are excellent, but this string’s comfort is downright surprising. It is getting harder and harder for me to stick with nylon. I feel like I can swing out with so much more confidence.” 5.5 male all-court player using Prince O3 White MP strung at 63 pounds LO (Wilson NXT)
“It is a rare treat to play with a polyester that has such great feel and playability. The spin is excellent and the tension maintenance is impressive.” 5.0 male baseliner with heavy spin using Wilson KPro Tour strung at 52/58 pounds CP (Natural Gut/Luxilon Big Banger Original Rough 16/16L)
“This has impressive power for a durability string. The playability and touch provide the advantages of a nylon multifilament. Polyester technology is changing for the better! “ 4.5 male all-court player using Wilson KSix.One (18x20) strung at 60 pounds CP (Gamma Asterisk 17)
“This string feels very solid. Control is excellent, and power is surprisingly high. Slower swings and touch shots are slightly harder to gauge, but spin comes very easily. I would definitely carry it.” 4.5 male all-court player using Wilson KFour strung at 60 pounds CP (Luxilon Big Banger XP 16L)
“I would not recommend this string to senior players who prefer comfortable strings. I let my big hitting son use it and he loves it.” 5.0 male all-court player using Babolat Pure Drive Roddick + strung at 56 pounds CP (Gamma Asterisk 17)
“This string does everything well, save touch shots. The power is on the low side, unless you have high head speed. Tension maintenance is quite good and string movement is negligible. After 30 hours it still plays fresh. Though it is best for heavy hitting baseliners, other folks may also enjoy the control it offers.” 5.5 male all-court player using Head MicroGEL Radical Pro MP strung at 60 pounds LO (Prince Synthetic Gut w/Duraflex 16)
“Players who like Luxilon Alu Power, with its great durability and control, are advised to try this string. It does not have quite as much spin or power. The touch and comfort are excellent.” 5.0 male all-court player using Prince Tour Diablo MP strung at 62 pounds LO (Luxilon Big Banger Original 16L)
“I am not a big fan of polyester, but this one definitely has potential. Control, and spin are pretty good. Comfort is a tad low. At the right price, I’d carry it in the shop.” 4.0 male all-court player using Prince O3 Hybrid Spectrum MP strung at 60 pounds CP (Head RIP Control 17)
“Feel on ground strokes is great. I don’t have to make adjustments to achieve the right height over the net. Defensive counter punches have enough power to reach the back court.” 4.5 male all-court player using Wilson KSurge strung at 58 pounds LO (polyester/Wilson Sensation 17/17)
“Great control and spin. Unfortunately, I have to swing too hard in order to generate power and depth. This is a great string for people who make their own power. For players with shorter strokes, you are advised to lower the tension or make a hybrid.” 4.0 male all-court player using Wilson nSix One (68 Holes) strung at 65/60 pounds LO (Klip Armour Pro 16)
“The more I hit with it, the more I like it. Power is excellent, especially compared to other polyesters. Groundstrokes feel very solid and volleys have excellent pop. Tension loss after 20 hours decreases playability slightly, but the control and spin never waiver.” 5.0 male all-court player using Wilson KBlade Tour strung at 55 pounds CP (Wilson Champions Choice 16)
“Very crisp. The string bed feels very even. The stiffness and high degree of control are achieved without sacrificing too much comfort.” 5.0 male all-court player using Prince O3 Speedport Black strung at 60 pounds CP (Prince Synthetic Gut Original 16)
“The spin potential is decent. I would recommend the string for hard hitters who hit with topspin. Those prone to tennis elbow may not like the string’s stiffness.” 4.5 male all-court player using Pro Kennex Kinetic Pro 7g strung at 58 pounds LO (Gamma Live Wire XP 16)
“There is noticeable stretching during tensioning. Tension maintenance and durability are impressive. The string bed feels very solid. String movement is minimal. Spin, power, and control are excellent. The string bed delivers energy with a pronounced snap. This string plays consistently from beginning to end.” 4.5 male serve-and-volley player using Wilson Hyper Hammer 2.3 Stretch OS strung at 55 pounds LO (Wilson Sensation 17)
“The response is crisp and comfortable. The power is a little low for my taste, so I find myself swinging a little too fast. This creates control problems, especially on shots where I do not have enough time to prepare.” 3.5 male baseliner with moderate spin using Head Protector MP strung at 56 pounds LO (Wilson Sensation 17)
“Installation is quick and easy. Very little friction burn on the crosses. Strings are easy to straighten and knots cinch-up tight. Very low elasticity on tensioning. Good tension maintenance. Great spin potential. Hard on the arm. This string would be great in a hybrid.” 4.0 male baseliner with heavy spin using Head Liquidmetal Radical MP strung at 50 pounds CP (Signum Poly Plasma 17)
“The playability and comfort not are not strong suits. The combination of control, spin, and durability make this ideal for big hitters. For players who favor a soft response, I would recommend using this in a hybrid.” 4.0 male all-court player using Prince O3 Speedport Blue strung at 60 pounds LO (Prince Synthetic Multifilament 16)
“This string is too stiff. For a polyester, though, it has some serious power.” 4.0 male baseliner with heavy spin using Head i.X6 OS strung at 62 pounds LO (Tecnifibre X-One Biphase 17)
“This string plays very stiff. This is not a great string for those in search of comfort and touch.” 5.5 male all-court player using Prince O3 Tour MS strung at 56 pounds CP (Prince Synthetic Gut w/Duraflex 16)
“I’m not a polyester fan and this string has done nothing to change my mind. It plays dead and never seems to soften up. Power is lower than I prefer and the feel is sub par. Not my cup of tea.” 4.0 male all-court player using Völkl V1 Classic strung at 56 pounds CP (Tecnifibre X-One Biphase 16)
(Strings normally used by testers are indicated in parentheses.)
Playtester ratings
EASE OF STRINGING (compared to other strings) |
|
---|---|
Number of testers who said it was: | |
much easier | 0 |
somewhat easier | 5 |
about as easy | 18 |
not quite as easy | 14 |
not nearly as easy | 2 |
OVERALL PLAYABILITY (compared to string played most often) |
|
Number of testers who said it was: | |
much better | 0 |
somewhat better | 5 |
about as playable | 17 |
not quite as playable | 16 |
not nearly as playable | 0 |
OVERALL DURABILITY (compared to other strings |
|
Number of testers who said it was: | |
much better | 4 |
somewhat better | 22 |
about as durable | 12 |
not quite as durable | 0 |
not nearly as durable | 0 |
RATING AVERAGES From 1 to 5 (best) |
|
Playability | 3.1 |
Durability (11th overall) | 4.3 |
Power | 3.3 |
Control (19th overall) | 3.7 |
Comfort | 3.0 |
Touch/Feel | 2.8 |
Spin Potential (19th overall) | 3.5 |
Holding Tension | 3.4 |
Resistance to Movement (16th overall) | 3.9 |
See all articles by Greg Raven
About the Author
Greg Raven is an associate editor for Tennis Industry magazine and technical writer. He is certified as a Master Racquet Technician by the U.S. Racquet Stringers Association. He can be reached via e-mail at greg@usrsa.com, or through Facebook, LinkedIn, and Twitter. He plays tennis three to five days a week, and is turning into an avid cyclist.
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