Tennis Industry magazine


Playtest: Wilson Optimus 16

By Greg Raven

Wilson’s Optimus 16 is a multicore multifilament nylon string with a couple of features not found in traditional strings of this type. First, there is a thermoset co-polymer membrane that encircles the nylon fibers to minimize tension loss and absorb shock. Second, a Tension Seal membrane reduces string “creep” for consistent feel.

Wilson tells us this string offers maximum tension maintenance for long-lasting playability. The company believes Optimus is ideal for players looking for crispness and additional feel in their shots with a string that has 15 percent greater tension maintenance than comparable multifilament strings.

The target consumer for Optimus is any player looking for a comfort-oriented multifilament that offers crisp response and excellent tension maintenance.

Optimus is available in 16 only in white or silver. It is priced from $9.10 for 40-foot sets. For more information or to order, contact Wilson at 800-272-6060, or visit Be sure to read the conclusion for more information about getting a free set to try for yourself.

In the Lab

We tested the white Optimus. The coil measured 41 feet, 3 inches. The diameter measured 1.23-1.25 mm prior to stringing, and 1.16-1.19 mm after stringing. We recorded a stringbed stiffness of 80 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 71 RDC units, representing an 11 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. In lab testing, Prince Synthetic Gut Original has a stiffness of 217 and a tension loss of 11.67 pounds, while Wilson Optimus 16 has a stiffness of 161 and a tension loss of 15.13 pounds. Optimus 16 added 13 grams to the weight of our unstrung frame.

The string was tested for five weeks by 33 USRSA playtesters, with NTRP ratings from 3.5 to 5.0. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. Average number of hours playtested was 20.

Out of the package, Optimus has a nice pearlescent or iridescent appearance. We had to adjust our clamps in a lot to prevent slippage, although some of that may have been due to the difference between the hardness of the polyester 16 we’d previously strung and the softness of the nylon Optimus 16. Optimus feels slippery during handling without being obviously lubricated, and when we were done with the crosses they were almost perfectly straight — a real time-saver.

No playtester broke the sample during stringing, none reported problems with coil memory, none reported problems tying knots, one reported friction burn, and three reported other problems.

On the Court

Our playtesters gave Optimus 16 three top-20 ratings. They rated it 5th best in Comfort (with two other Wilson strings ahead of it!), 9th best in Touch/Feel, and 19th best in Playability of the 178 strings we’ve playtested to date for publication. They also rated it well above average in the Power category. On the strength of great showings in these four categories, Optimus 16 rated above average overall.

Four playtesters reported premature fraying or peeling, none reported buzzing, and nine reported notching.

Thirteen players broke the sample during the playtest period, one at 1.8 hours, one at 2.5 hours, one at 3.5 hours, two at 8 hours, one at 10 hours, two at 12 hours, and one each at 15, 17, 20, 31, and 45 hours.


Optimus 16’s strengths should really appeal to older and recreational players, who will get just what they want from this string, and who don’t hit the ball in such a way that they’ll ever notice its weaknesses in Spin Potential, Durability, and Resistance to Movement.

Playtester comments

“Extremely comfortable string with excellent balance of comfort, control, power, and spin. I will stock this string as soon as I find out what it is.” 4.0 male baseliner with moderate spin using Prince O3 Speedport Black strung at 50 pounds CP (Tourna Armor 17)

“A very interesting string. I found it to be a great control string, but not at the expense of power. When volleying, you could really feel the bite, which helped in giving you a crisp and exacting shot. You can say this string is like driving a high performance car, the harder you drive it, the better it performs.” 4.5 male serve-and-volley player using Head Radical MP strung at 55 pounds CP (Wilson Hollow Core/Genesis Black Magic 17)

“The string hit very well! Plenty of power and easy on the arm. Already had folks asking me about the string due to its cool look! Highly recommended!” 4.0 male baseliner with heavy spin using Babolat Pure Drive Roddick strung at 62 pounds LO (Solinco Tour Bite 16L)

“A solid string with good performance across most measurements. Nice feel on touch shots, good power, very comfortable. I did find myself constantly adjusting strings after a rally, but this was a minor issue. I could play with this string on a regular basis. Would be great in a hybrid with poly!” 4.0 male baseliner with moderate spin using Head IG Extreme S 2.0 strung at 57 pounds CP (Head Hawk 17)

“I was pleasantly surprised by the power this string offered. Good control on volleys and return of serve. This string responded well to everything I threw at it. Definitely would recommend to my customers!” 4.0 female all court player using Babolat Pure Drive strung at 62 pounds CP (Head FXP 17)

“This string had a nice balance of comfort and control. Tension maintenance was the best quality. The tension stayed consistent until the string broke.” 4.5 male serve-and-volley player using Babolat Pure Control strung at 55 pounds CP (Luxilon 4G 125)

“Good soft feel on arm and shoulder.” 4.0 male all court player using Volkl V1 Classic strung at 56 pounds CP (Wilson Hyper Spin 19/16)

“A wonderful feeling for those players who don’t typically have durability issues. Feels comfortable with good power and comfort.” 5.0 male all court player using Head Graphene Speed Rev strung at 63 pounds CP (Luxilon Timo 110 18)

“I am suffering from frozen shoulder and have strung my racquet with this string as it is softer and much more forgiving than my regular string. I was not disappointed with its performance and comfort. I gained power, but lost some spin.” 4.0 male all court player using Head Graphene Pwr Speed strung at 52 pounds CP (Gamma Moto 17)

“A crisp but arm-friendly string with great power, control and feel. Without a doubt this string added huge speed and pinpoint control on the first serve and heavy spin for the second serve. Such a great feeling to be able to spot the serve even with the added serve speed. Awesome. Volleys were also easy to control with an easy feel and little to no shock on the arm. Groundstrokes with a long swing were firm and not mushy or trampoline-like for such a soft string. Directional control was great, however, a little more difficult to dial in depth unless the contact point was in front, as it should be. One of the best strings with respect to playability from the first hit to the time the string broke. Easy to know what you are feeling throughout the entire playtest. String movement and durability were the downside which would be expected for such a thin, soft string. Overall, would recommend this string for serve and volleyers, players with a shorter swing or players that want a monster serve without any discomfort.” 4.5 male baseliner with heavy spin using Head Graphene Speed MP strung at 60 pounds CP (Ytex Pro Tour 17)

“The string felt crisp and more lively than my typical string. It had more feel than the poly strings I usually play with. The tension held up nicely but the strings started to move later in the test, the lack of which is something I really like with my poly strings. It was a nice switch to play with something that has feel and comfortable to play with.” 4.0 male all court player using Pro Kennex Kinetic Pro 7G strung at 60 pounds CP (Luxilon Big Banger ALU Power 16)

“String diameter measured 1.28 - 1.30mm prior to stringing, and 1.25 - 1.27mm after stringing. Stringing was a little tedious due to coil, but no notching or burning. The first two hours of play the string was a bit stiff and had to be worked over to get depth and feel. After the first two hours of play the string settled in nicely. Good feel, power, and decent spin. As play continued, the string was still comfortable but power increased and control diminished. Feel was still good but string movement increased. Overall, a good synthetic string with a nice balance of power, spin, and feel.” 4.5 male all court player using Yonex VCore 98D strung at 55/52 pounds CP (Tecnifibre X-One Biphase 17)

“Although the string broke after 1 hour of teaching and 3/4 hour of playing, I thought the string had exceptional comfort and power potential. Limited tension loss compared to other strings in the soft playability string category. Fantastic string choice for a player who doesn’t break strings looking for an arm-friendly string.” 4.5 male all court player using Wilson Juice 100S strung at 61 pounds CP (Luxilon 4G Rough 125 17)

“This certainly didn’t feel like a polyester, very little recoil memory and softer. It felt great teaching because it was easier on my wrist, elbow, shoulder than the polyester strings. However, I couldn’t keep it in the first few times I played with it. it has much more power than the poly I am used to. Also, it is much harder to generate spin with this string. As I got used to it and adjusted my game, it felt good. However, it broke after 4 times playing (around 7 hours). This normally happens if I use regular synthetic gut strings or a multifilament. Very nice string for older club members who need power, don’t break string often, or a softer string that is easy on the body. This is a string I would sell at my club, although I wouldn’t use it myself.” 4.5 male baseliner with moderate spin using Head Speed Elite strung at 58 pounds CP (Tourna Big Hitter 7 16)

“The string has great touch and feel. It had ample power but was lacking with spin. I felt more comfortable with the string due to its softness.” 3.5 male baseliner with moderate spin using Head Graphene Prestige MP strung at 53 pounds CP (Head Hawk 18)

“Very good combination of power and control. Loved the pop I got on my serves. String seemed to really bite the ball on all groundstrokes. The feel/touch was moderate. Would love to try this string in a thinner gauge. Overall, I enjoyed this stirng.” 4.0 male serve-and-volley player using Dunlop Biomimetic M 2.0 strung at 53 pounds CP (Wilson Sensation/Prince Synthetic Gut 17/18)

“Nice comfort, would work well in a poly hybrid. This string would complement a player who uses touch. There is major string movement for a topspin player, resulting in low spin potential.” 4.0 male baseliner with heavy spin using Dunlop Aerogel 4D 1 Hundred strung at 40 pounds LO (Wilson Enduro Pro 17)

“This string was one of the easiest strings to install that I can remember. There was a good coating that virtually eliminated friction burn, it was very soft, it did not kink, and knots were easy to tie. Although I was expecting the feel of a soft multifilament when playing, it surprised me that it felt much stiffer than the 54 pounds that I installed it. Throughout the playtest, the tension held really well as I did not really notice any sort of drop off even toward the end of the testing. Bite on the ball seemed above average where I could easily grip the ball for topspin, slice, or kick serves. I would definitely carry this string in my inventory for someone who is looking for a softer string that still holds tension well with above average string bite.” 4.0 male all court player using Head Graphene Speed Pro strung at 54 pounds CP (Head Rip Control 17)

“My first impression on seeing the string was that it has bling. Interesting sparkle effect. Very easy to handle and string. Knots tie easily. Doesn’t push through blocked holes as easily as some other strings however. The first time I played the string I was impressed. Great pop and control. Second time out was OK. By the third time out, around five hours of play, I felt the string had lost much of the pop and control, and the mains began moving. I somewhat struggled to get my 15 hours of playing time in, and by the end I can only say they were playing just OK. I loved them at first, and was tolerating them by the end. If these strings were in the synthetic gut price range (under $5). I would consider buying them. But, I suspect that will not be the case. Although I really liked the way they played at first, I wouldn’t want to invest much more in string that lost it so quickly.” 3.5 male all court player using Wilson Blade strung at 55 pounds CP (Solinco Tour Bite 16L)

“The string was a comfortable, softer string that bit the ball fairly well but didn’t give me the power on groundstrokes that I get from my usual polyester string.” 5.0 male all court player using Babolat Pure Drive + strung at 46 pounds LO (Luxilon ALU Power/Babolat Pro Hurricane 16)

“A lot more slippage on this string than I am used to. I usually use Sensation in the crosses for many people I string for and this string feels like it would be a good string for a hybrid pattern, with it being the softer string in the crosses to offset a more durable poly in the mains.” 4.0 male all court player using Babolat Pure Drive strung at 60 pounds CP (Luxilon Big Banger ALU Power 16)

“Very soft and nice string. I would say its comparable to most synthetic gut strings. It felt thinner than a 16 gauge.” 5.0 male baseliner with heavy spin using Babolat Pure Drive strung at 56 pounds LO (Luxilon 4G 16L)

“The string played great for the first 5-6 hours. I enjoyed the crisp (for a multi) feel, as well as the consistency of response from the stringbed. After 6 hours of play, the string softened and played inconsistently (mushy/too springy at times). Though the string did fray substantially toward the end of its life, it did not notch much at all. Overall, a decent offering, but nothing special.” 4.5 male all court player using Prince EXO3 Rebel strung at 59 pounds CP (Solinco Tour Bite/Prince Premier Control 18/17)

“Although I didn’t feel any pop or bite from this string, it was quite comfortable on impacts. Best suited for beginner to intermediate or senior players. This would make a nice combo as a blended string in the crosses. I didn’t experience any snap back from this string and it moved around a lot in the first several hours of play. If this string is high priced, it could be a deal breaker.” 4.5 male all court player using Babolat Pure Drive Roddick strung at 50 pounds CP (Solinco Tour Bite/Solinco Vanquish 18/16)

“I felt that the string could have used more power. The tension holding seemed to be satisfactory. No knot-tying problems, coil memory was not evident, although during stringing the string wanted to knot or kink. Spin was okay, nothing special. Control was good. Crosses began showing fraying in the sweet spot area. Comfort was OK, nothing special, not hard on the arm at all. Durability was not great, but even with the breakage at 31 hours, that’s about where I usually replace the strings anyway. Control was reasonable, although nothing special. Power was okay. Playability was in the mid range.” 4.0 male all court player using Head Youtek Graphene PWR Instinct strung at 57 pounds LO (Prince Lighting XX Spin )

“I wish all strings were as easy to string as this test string. Very soft string with high comfort, but durability extremely lacking. May work well as a hybrid on the crosses. Overall play just average with no exceptional feature but comfort.” 4.5 male all court player using Babolat Pure Storm GT Tour + strung at 58 pounds CP (Yonex Poly Pro Tour 16)

“String felt good, but that doesn’t mean it’s better than my usual poly.” 5.0 male all court player using Head Radical MP strung at 50 pounds CP (Poly 16)

“It was unfair of me to playtest this string in my normal frame. I’d string future nylon playtest strings on a frame with a more conventional string pattern. That said, the strings moved excessively and didn’t snap back into place. I felt that string movement hurt my spin generation and control. I didn’t find any play characteristics of this string to make it more interesting than my standard value synthetic gut.” 4.0 male baseliner with heavy spin using Wilson BLX Six One 95 S strung at 60 pounds CP (Luxilon ALU Power Spin 16)

“Initially the string performed nicely. It felt like I had a nice pocket in the stringbed on all shots. But, after a couple of intense hitting sessions the string felt as if it had lost its resiliency. Needless to say, the control aspect of the string suffered. At about the same time the string movement became an issue. I found myself adjusting the strings every other shot. Trying to blast away with my hitting partner became almost impossible as ball control was greatly compromised. By no means a string I’d care to use or stock.” 4.5 male all court player using Babolat Aeropro Drive GT strung at 58 pounds LO (Tourna Quasi Gut 16)

“Not as comfortable as other synthetics I’ve used. Seemed to lose elasticity and become quite rigid after only a couple hours. Excessive string movement became an issue, ultimately leading to fairly premature breakage.” 4.0 male all court player using Babolat Pure Drive Roddick strung at 57 pounds CP (Wilson NXT 17)

“This was not one of my favorite strings. The main strings moved a lot during play. The tension held fine, but for those heavy topspin players, way too much string movement.” 5.0 male serve-and-volley player using Yonex Vcore Xi strung at 65 pounds CP (Yonex Poly Pro Tour 125 17)

“Strings up easily. Soft and pliable. A nice change from stiff poly strings. Interesting color hues. Not a big performer on court. No access to spin on serves. Lost tons of tension. I would not offer this to customers.” 4.5 male all court player using Head Youtek IG Speed Lite strung at 59 pounds CP (Ashaway Monogut ZA 1.25 16L)

“I wanted to give this string the full 15 hours, but it gave nearly no spin. Very unpleasant to have in my racquet. This string was extremely easy to install.” 4.0 male all court player using Babolat Aero Pro Drive strung at 55 pounds CP (Tourna Big Hitter Black 17)

(Strings normally used by testers are indicated in parentheses. For the rest of the tester comments, visit

Playtester Ratings

Ease of Stringing (compared to other strings)
much easier 9
somewhat easier 13
about as easy 9
not quite as easy 1
not nearly as easy 0
Overall Playability (compared to the string played most often)
much better 2
somewhat better 14
about as playable 7
not quite as playable 7
not nearly as playable 3
Overall Playability (compared to other strings of similar gauge)
much better 0
somewhat better 4
about as durable 14
not quite as durable 10
not nearly as durable 4
Rating Averages
From 1 to 5 (best)
Playability (19th overall) 3.7
Durability 2.8
Power 3.5
Control 3.4
Comfort (5th overall) 4.0
Touch/Feel (9th overall) 3.7
Spin Potential 2.8
Holding Tension 3.2
Resistance to Movement 2.3

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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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