Tennis Industry magazine


Playtest: Wilson Stamina 17

By Greg Raven


Wilson introduced Stamina in 2002 as a durability-oriented synthetic gut in 16 gauge only. Since then, Stamina has become so popular that Wilson now offers it in two additional gauges — 17 and 18 — and in more colors (listed below). Stamina is composed of a solid co-polymer (nylon) center core with an outer wrap of ten Tensilast and ten nylon fibers. Wilson tells us that it is the Tensilast fibers that make the string 25 percent more durable than other synthetic guts without increasing “stiffness,” and that Tensilast helps with tension maintenance and a more resilient feel compared to other durability-oriented synthetics. In Wilson’s lab tests for string durability for ball impact, Stamina 17 outlasted other 17 gauge synthetics guts and many 16 gauge synthetic guts.

Stamina is available in sets and reels of 16, 17, and 18 gauge. Stamina 16 is available in white, light green, silver, and retro spiral. (We published a playtest review of Stamina 16 in August 2002.) The 17 gauge is available in white, light green, silver, and light orange. Stamina 18 is available in white only. Stamina 17 is priced from $4.25 for sets of 40 feet and $55.00 for reels of 660 feet (white only). For more information or to order, contact Wilson by phone at 773-714-6400 or web site. Wilson gave a free set of Stamina 16 as well as a free sample of their new Pro Overgrip (introduced in the January 2002 issue) to every U.S. member in April 2002.

Wilson Stamina 17

Bench testing

We tested the 17 gauge Wilson Stamina. The two coils measured 42 feet 4 inches and 42 feet 6 inches. The diameter measured 1.25 mm to 1.26 mm prior to stringing, and 1.20 mm after stringing. We recorded a stringbed stiffness of 86 RDC units immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 × 18 pattern) on a constant pull machine. After 24 hours (no playing), stringbed stiffness measured 78 RDC units, representing a 9% 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% tension loss. Wilson Stamina added 11.9 grams to the weight of our unstrung frame.

The testers

Tested for five weeks by 28 USRSA playtesters, with NTRP ratings from 3.5 to 6. These are blind tests, with playtesters receiving unmarked strings in unmarked packages, to reduce preconceptions and biases regarding manufacturers, type of construction, and materials. Average number of hours playtested was 18.8.


Wilson Stamina 17 is easy to install, as noted by every single one of our playtesters. Nearly half of our playtesters felt that Stamina 17 was either easier or much easier to install than other strings, and the rest felt that it was at least as easy to install as other strings. About the only unusual aspect of using it is a slight “sawing” sound when rubbing the strings against each other (for example, when pulling the crosses), or through grommets.

No playtester broke his sample during stringing, one reported a problem with coil memory, none reported problems tying knots, and none reported friction burn.


Our playtesters rated Stamina 17 well above average for playability, power, and spin potential. They also rated it above average for control, touch/feel, comfort, and tension holding. The only characteristics that did not receive above-average scores were Durability and Resistance to Movement. But when asked to compare Stamina 17’s durability against other strings of similar gauge, most playtesters rated it comparably durable or better.

As you might expect from these ratings, Stamina 17 does not give the immediate first impression of being a durability string, which is to say that unlike some durability strings, you don’t think to yourself, “It doesn’t feel or play very well, but I’ll put up with it because I know it’s going to last.” The fact that it’s going to be around for the long run starts to dawn on you after a couple of weeks, when it still seems to be playing as well as you remember it playing when it was newer. Long after installing Stamina 17, it continued to deliver predictable results, while other strings came and went.


The thinner gauge and enhanced playability of the 17-gauge Stamina are likely to be welcomed by players needing string with better durability, who are not quite ready to switch to a poly. Given its playability and high ratings for control, it should be good in oversize racquets. Based on the playtest results of Stamina 16 (August 2002), players who like the feel of 17-gauge Stamina and are willing to give up some of the spin potential for better durability and tension holding may prefer Stamina 16.


“This string was extremely easy to work with. I really liked how it gave the feeling of “bite” and thus I felt like I had lots of control. This is a very “comfortable” string with which to play.” 4.5 female all court player using Prince More Control DB 800 strung at 56 pounds CP (Tecnifibre NRG2 17/18)

“Great string. Felt great immediately. Very good at holding tension for such a good-feeling string.” 5.0 male baseliner with moderate spin using Prince Air Drive 900 strung at 62 pounds CP (Prince Sweet Perfection 17)

“It was easy to install the test sample. It did not exhibit any negative characteristics, which is nice in this era of poly strings. On court, I couldn’t find my normal volley stroke because this string seems to have less power than my regular string, but highly-angled volleys and groundstrokes were great. It also seemed to hold tension well over the weeks I had it in my racquet. I’d like to try it again, strung a bit lower. I think my groundstrokes would still stay in, and I’d get more pop on my volleys.” 4.0 male all court player using Wilson ROK strung at 60 pounds CP (Pacific TourGut 16L)

“The string felt wonderful from the first time I played with it until it broke. It never had that boardiness that most fresh string jobs have. I was shocked when it broke after eight hours of play. I still would carry this string, based on its overall playability.” 3.5 male baseliner with heavy spin using Dunlop 200G strung at 65 pounds CP (Prince Syn Gut w/Duraflex 17)

“This felt to be a quality synthetic gut from the first hit. Very good control. I had the feeling that I could swing freely without fear of the ball sailing. Comfort was slightly above average, but feel was a bit lacking due to a slightly muted feel. Not a real stand-out in any one category except control, but a solid all-around performer. If the price is right, it should find a niche.” 4.5 male baseliner with heavy spin using Pro Kennex 7G strung at 66 pounds CP (Prince DNA Helix 16)

“This string performed pretty lively during match play. I was surprised with its performance on touch shots. Other than excessive movement of the strings, I would not mind recommending it to my customers.” 3.5 male all court player using Wilson Hyper Pro Staff 6.1 strung at 54 pounds LO (Tecnifibre NRG2 17)

“A nice string that held tension quite well! Some of my better players might like this string if the price was right.” 6.0 male all court player using Prince More Precision strung at 70 pounds CP (Prince Sweet Perfection 16)

“This string installed in a straightforward fashion, which was a considerable relief after installing so many polyester-based strings. I enjoyed using this test string and found it to be firm-playing while maintaining excellent control and feel. I do think that the string seemed to lose tension a little sooner than some, but the overall playability of the string made up for the shorter string life.” 3.5 male baseliner with moderate spin using Wilson Triad 3 strung at 54 pounds CP (Prince Wrapsure 17)

“I found this string to have lots of power, control, and added spin. There was a drop-off in tension after 8-10 hours of play, and an increase in string movement. I like this string but it needs to be strung at a higher tension.” 5.0 male baseliner with heavy spin using Head Classic MP strung at 62 pounds CP (Gosen JCC 17)

“I like this test string. It’s a good-playing 17-gauge that would probably play well in many, many racquets. I think it has above-average control, comfort, feel, and spin potential. It was fun to play with, and it enhanced my playing sessions.” 5.5 male serve and volleyer using Wilson Hyper Carbon Pro Staff 6.7 strung at 53 pounds CP (Wilson NXT/natural gut 16)

“A very likeable string. I felt that it wasn’t going to last long when I strung my racquet but, like an ocean sunset, I pledged to savor every moment. Felt good on my arm, provided touch as well as power, and held its tension better than my usual string. I would consider switching to this if the price is right.” 5.0 male all court player using Head i.radical OS strung at 54 pounds LO (Prince Syn Gut Original 17)

“I felt this string had a nice, somewhat soft, feel, with good overall power and spin potential. Due to the thin gauge, I believe the string broke earlier than previous test strings I have playtested.” 5.5 male all court player using Volkl C10 Pro strung at 62 pounds CP (Gamma Live Wire XP 16/17)

“I was surprised how well this string played. It felt like a stiffer Prince synthetic. It was very easy to handle and string. I had no difficult tying knots. I liked the way it bit the ball. Durability-wise it wasn’t that great, but that could be because of my extreme topspin. Would I carry this string? Yes.” 4.5 male all court player using Prince More Control DB strung at 58 pounds LO (Prince Lightning XX 16)

“This is a very simple string that had surprising power and nice comfort. It seemed to be a basic synthetic gut, probably a monofilament. It played very well at my low tension and I didn’t need to use a vibration dampener to quiet the sound. However, the durability is a serious issue. It notched right away and broke after only six hours of play.” 5.0 male serve and volleyer using Handler Arrow strung at 38 pounds LO (Gamma Fusion 19)

“At 17-19 hours the string became loose and started to move a lot. Also, the ball seemed to fly a bit more, but overall it retained a good touch and feel, similar to my 17-gauge string.” 3.5 male all court player using Head i.X6 strung at 60 pounds LO (Prince Syn Gut w/Duraflex 16/17)

“Played the same as an average synthetic string. It felt just like Prince Syn Gut: A good average string with nothing unusual to note.” 5.0 male baseliner with moderate spin using Wilson 6.1 Stretch strung at 61 pounds LO (Gamma ESP 16)

“This was a nice overall string, but no outstanding characteristics.” 4.0 male all court player using Pro Kennex Kinetic Charged strung at 65 pounds LO (Tecnifibre TrC 16)

“I was surprised to find that the elasticity of the test string appeared to exceed that of Wilson Sensation 17.” 3.5 male all court player using Wilson Hyper Hammer 2.3 strung at 57 pounds CP (Wilson Sensation 17)

“A satisfactory string. The only negative was string movement. Stringing was quite easy, but I could not rate it higher than average.” 4.0 male all court player using Fischer Pro Impact FT strung at 58 pounds CP (BDE Perf 17)

“This sample was very easy to string. Weaving was easy and knotting was not a problem. Playing-wise, however, it was an average string. I had too much power and not enough control.” 4.0 male all court player using Gamma Diamond Fiber M-6.5 strung at 65 pounds CP (Tecnifibre NRG2 17)

“I liked the control and the power the string provided, but it didn’t last long enough.” 4.5 male baseliner with heavy spin using Dunlop 300G strung at 60 pounds LO (Babolat Ballistic 16)

“An absolute breeze to string. Very well behaved. This string played much firmer than I thought it would, based on its feel and how it strung up. I had expected more feel and resilience. Though I have been using more topspin lately, I was surprised it broke so quickly, especially as it wasn’t moving very much or showing other signs of wear.” 4.5 female all court player using Wilson Hyper Hammer 3.3 strung at 60 pounds CP (Wilson NXT 16)

“This string was okay but I prefer a softer feel. It seemed that the manufacturer tried to breed a poly and a multifilament string and got a mess.” 5.0 male all court player using Prince More Control DB 850 strung at 58 pounds LO (Prince More Feel / Head FiberGel 16)

“Nothing special about this string.” 5.0 male all court player using Pro Kennex 7G strung at 66 pounds LO (Tecnifibre Promix 16)

“This synthetic had no outstanding features to write about. Everything was average to sub-par. Comfort wasn’t much and a generic stiffness made me lose interest in this string very quickly.” 4.5 male all court player using Volkl Catapult 2 strung at 51 pounds LO (Forten Dynamix 16)

“I did experience some discomfort in the shoulder from serving. I don’t know if it was due to the strings, though.” 3.5 male all court player using Gamma M-6.5 strung at 55 pounds CP (Gamma TNT 16)

(Strings normally used by testers are indicated in parentheses.)

Playtester ratings

(compared to other strings)
much easier 3
somewhat easier 10
about as easy 15
not quite as easy 0
not nearly as easy 0
(compared to the string played most often)
much better 1
somewhat better 3
about as playable 12
not quite as playable 11
not nearly as playable 0
(compared to other strings of similar gauge)
much better 0
somewhat better 9
about as durable 12
not quite as durable 5
not nearly as durable 1
Playability 3.5
Durability 2.9
Power 3.4
Control 3.5
Comfort 3.4
Touch/Feel 3.3
Spin Potential 3.3
Holding Tension 3.2
Resistance to Movement 2.6

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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, 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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