Tennis Industry magazine


Playtest: Tecnifibre HDX Tour 17

By Greg Raven

Tecnifibre HDX Tour is a multifilament string constructed of thousands of fibers in multiple separate bundles held together by an exclusive Tecnifibre polyurethane-infusing process. The combination of the unique fibers involved and the polyurethane process creates a string with that expected Tecnifibre feel, improved longevity, enhanced spin potential and increased absorption of impact shock.

Each bundle consists of sub-bundles of three different fibers: 34 percent Elastyl fibers for elasticity and power, 33 percent polyester fibers for firmer feel, and 33 percent Thermostabyl fibers for spin and snap-back. The outer surface has a light coating of SPL lubricant, for anti-abrasion and durability.

According to Tecnifibre, the development of HDX Tour came out of the reality that lighter racquets (that is, those under 300 grams/10.5 ounces) transmit more impact shock to the player, and generate less power, making them less suitable for polyester strings. After three years of R&D, Tecnifibre claims HDX Tour gives all types of players the sensation of using polyester strings, with the power and comfort of the multifilaments for which Tecnifibre has become famous.

Tecnifibre says that HDX Tour is also 15 percent more durable than its next most durable multifilament string.

Tecnifibre designed this string for competitive players who want controlled power and spin in a durable string, but who cannot use stiff poly strings due to physical limitations or discomfort. HDX Tour is also for those who want more durability out of their current multifilament string without sacrificing comfort and playability.

HDX Tour is available in 16 (1.30 mm) and 17 (1.24 mm) in natural. It is priced from $20.95 for sets of 40 feet. Instead of reels,

Tecnifibre offers qualified retailers an Ecobox of 20 pieces of 40-foot sets, in the same color and gauges as individually packaged sets. For more information or to order, contact Tecnifibre at 888-TFTennis (888-838-3664), 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 17-gauge HDX Tour. The coil measured 40 feet. The diameter measured 1.23 mm prior to stringing, and 1.21 mm after stringing. We recorded a stringbed stiffness of 81 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 73 RDC units, representing a 10 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 Tecnifibre HDX Tour 17 has a stiffness of 142 and a tension loss of 11.73 pounds. (HDX Tour 16 has a stiffness of 148 and tension loss of 10.56.) HDX Tour 17 added 13.7 grams to the weight of our unstrung frame.

The string was tested for five weeks by 38 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 27.4.

Tecnifibre HDX Tour has that familiar “grippy” feel of a polyurethane string, which sometimes contributes to creaking noises coming from the loop of string outside of the frame when pulling tension. It is soft enough that you may have a problem with severely blocked holes, but it has little coil memory, and is generally very easy to install. We had no problems pulling HDX Tour through tiny grommets, weaving crosses, tying knots, or straightening. The SPL coating is so light you may not notice it.

No playtester broke the sample during stringing, one reported problems with coil memory, one reported problems tying knots, one reported friction burn, and one reported other problems.

On the Court

Tecnifibre HDX Tour ranked highly with our playtest team. It garnered third place in Comfort (first place is a natural gut string), third place in Playability (first place is a natural gut string), fifth place in Touch/Feel, and 11th place in Power, out of the 180 strings we’ve playtested to date for publication. It also earned excellent rankings in both Control and Tension Retention, and well-above-average rankings in Resistance to Movement and Spin Potential. Overall, Tecnifibre HDX Tour is the sixth-best string on the list, making it the highest-ranked synthetic multifilament to date.

Six playtesters reported premature fraying or peeling, two reported buzzing, and 10 reported notching.

Eight playtesters broke the string during the playtest period, two at five hours, and one each at 8, 16.5, 18, 26, 49, and 72 hours.


Tecnifibre’s polyurethane strings always seem special, and HDX Tour continues the tradition. With seemingly the best features of both polyester and high-quality nylon strings, it is almost a one-piece hybrid that you will love to install.

Tecnifibre is making 300 free sets of HDX Tour available for USRSA members to try for themselves. So if you think Tecnifibre HDX Tour might be for you, fill out the coupon and send it in right away.

— Greg Raven

Playtester comments

“Great feel. Shots feel crisp and vibration free. String played exceptionally well from start to finish.” 4.0 male baseliner with heavy spin using Dunlop 200G strung at 65 pounds CP (Prince Synthetic Gut 16)

“Awesome feeling and playing string! Didn’t think it would be nearly as good as it was. Great power, comfort, and control. I did string tighter due to open “Spin” pattern. One of the best multifilament string I have ever played!” 6.0 male all court player using Wilson Juice 100S strung at 60 pounds CP (Luxilon 4G 16)

“Fantastic string! One of the best I’ve ever hit with. This string does it all; power, spin, playability, etc. Surely this must be some advanced hybrid mix of different materials. I could not believe that a string this crisp and yet comfortable could produce this much spin. Once I find out what this string is, I’ll be stocking it for myself and the people I string for. I played some of the best tennis in my life with this string. The enhanced power and spin really lead me to play a more aggressive style than I even normally play. My partners were even joking that they were looking forward to this test being over so things could calm down and go back to normal. This is the best overall string I’ve ever hit with. Loved it. I’d recommend it to just about anyone. Given that it plays slightly stiff even though out of the package it feels soft, I’d be worried about having people with pain issues adopt this for their use, I’d tell anyone else to try this string. It even has enough durability that I’d recommend even the string breakers/big hitters to at least try this in a hybrid. This is one of those rare strings that has something for everyone.” 4.5 male all court player using Wilson K Six One Tour strung at 60 pounds CP (Acelon Wildfire 1.30)

“Impressed from the start with ease of stringing and overall playability. Very comfortable string with good control, power and spin potential. A lot of movement in the strings once the tension started lowering. Early fraying signaled a potential for lower durability although they are not broken yet at the time of this writing. Holding tension seemed average compared to multifilament-type strings. Overall, I would definitely purchase and play with this string. Love the comfort and playability.” 3.5 male baseliner with moderate spin using Prince O3 Hybrid Hornet strung at 63 pounds LO (Pacific Natural Gut 16L)

“This was one of the best strings I’ve tested. It was easy on the arm. I felt it was very responsive for spin on groundstrokes, great touch and feel on volleys and half volleys, and it had good pop on the serve. It did break on me, but the string I use usually breaks after 6-7 hours. I’ll recommend this string to several of the players at my club. Can’t wait to find out what it is.” 5.0 male all court player using Wilson BLX Blade strung at 50 pounds LO (Tourna Quasi-Gut Armor 17)

“I would have to say this is one of the best strings I have tested/played with ever!! Strings with ease. Play qualities were excellent in all categories. This would make any player gain racquet confidence because it was so genuinely great in every area of play. Can’t wait to know what this one is as it will be a great string to have in stock.” 4.0 male all court player using Head Youtek Radical MP strung at 60 pounds LO (Babolat Xcel Premium 16)

“I liked this string’s playability and felt comfortable as much as I do with the string I normally use. As a serve and volleyer, great feel on the volleys, touch shots, and pop on the serve.” 4.5 male serve-and-volley player using Wilson BLX Two strung at 60 pounds LO (Wilson NXT 16)

“I really enjoyed playing with this string. I thought it provided good power, control, and feel. I would rate the string’s overall playability high.” 4.0 female all court player using Prince Warrior 100L ESP strung at 58 pounds CP (Tecnifibre 17)

“Nice, soft feeling, comfortable stringbed. Plenty of power with no noticeable string movement.” 3.5 male all court player using Head Youtek Four Star strung at 54 pounds CP (Head PPS 18)

“This was my favorite string other than a gut/poly hybrid. It is soft and powerful like a multifilament, but it slips and rebounds like a poly. Held tension almost as well as natural gut. Curious to see if it is a good main for a poly cross.” 4.5 male all court player using Babolat Pure Strike strung at 58/55 pounds CP (Babolat VS Gut/Babolat RPM Team 17)

“I loved that we got to test a non-poly string. Poly is not for everyone. String was very easy to install, almost too easy. Very easy on the hands, nice not worrying that the string is going to break on the tie-offs. This was a very nice multifilament type string. It compared very favorable to my usual $20 string. If the price point is competitive, this will be a nice string either as a full bed, or as a hybrid with poly for those who still must have poly. If it also came in a thin gauge, like 17 or 18 gauge, that would be a nice option.” 4.0 male all court player using Head Youtek IG Prestige Mid strung at 50 pounds LO (Gamma Professional 16)

“Easy to string and tie knots. Excellent comfort and touch/feel on all shots due to soft texture. Average spin potential and power, above average resistance to movement and very little tension loss. This string would be excellent as cross strings with polyester main strings for a hybrid mix.” 4.0 male all court player using Prince Triple Threat Viper strung at 60 pounds LO (Gamma Ruff 16)

“Pop O’Plenty! Good crisp volleys, strong groundstrokes, and good pop on serves. I think when I play with it more, I’ll get better touch and feel. Like this string, will add to arsenal if reasonably priced. Would be interested in a 17g. Might also be good to use as a hybrid with poly.” 4.0 male all court player using Prince O3 Red strung at 57 pounds CP (Gamma TNT Pro Plus 17L)

“String was feeling good on the arm, and had great control. Not too much movement on frame but snapped it about 18 hours in. I liked it too, so was hopeful it would last longer. Great feel is an understatement.” 4.5 male baseliner with heavy spin using Head Graphene Speed Pro strung at 58 pounds LO (Yonex Poly 17)

“Great feel and comfort string. Would recommend to other players. Good playing string that allows you to feel in control of your shots.” 5.0 male all court player using Head Graphene Instinct MP strung at 62 pounds LO (Head Sonic Pro 16)

“Very nice multifilament, would definitely recommend to 3.0-3.5 players, older 4.0+ players, and/or both.” 5.0 male baseliner with moderate spin using Babolat Pure Strike strung at 55 pounds CP (Babolat RPM Blast/Babolat Excel 17)

“I liked this string. it was overall very good in many categories, but it was not quite as good as the current strings I use. I did like the ease in stringing - no coil memory at all nor any problems with kinking or friction with crosses. This string did tend to hold tension better and last longer than my current string. I really liked the comfort - no vibration even with off-center hits. The string did prove to be well above average with minimal string movement, its ability to retain tension, and resistance to movement even when hitting heavy topspin. Overall, a very good string that provides both comfort and durability.” 4.5 male all court player using Prince O3 Blue strung at 55 pounds LO (Tecnifibre NRG/Babolat Xcel 17)

“What a pleasure to string a soft string again after so much poly. Very easy to string. The outlier points of this string were the high level of comfort and the control. Most shots went where intended.” 4.5 male all court player using Prince Tour 100 ESP strung at 57/60 pounds LO (Prince Tour XP 17)

“This was a very solid feeling string. There was a good amount of touch and feel with this string. It started to notch a bit after about 30 hours. I would recommend this as either half of a hybrid or in a frame that is not a spin-type frame or a player that is not too big of a hitter. There was an ample amount of power and control with the string and felt really easy on the arm. I enjoyed this string very much and would probably look to adding it in the crosses of a hybrid.” 5.0 male serve-and-volley player using Wilson BLX Juice 100S strung at 61 pounds LO (Luxilon 4G/Wilson NXT 16)

“I was surprised at the elasticity that this string produced when serving and trying to hit hard ground strokes. It was especially pleasing on the first serve.” 3.5 male all court player using Wilson strung at 50 pounds CP (Wilson Sensation 17)

“I have gotten used to polyester, but I enjoyed stringing it as well as playing and teaching with it. Easy on the arm. I had plenty of power as well as control and comfort. Very little shifting of strings. I would recommend to my members that were not string breakers for comfort and control.” 5.0 male all court player using Prince Warrior strung at 50 pounds CP (Dunlop Black Widow 18)

“This is a nice multifilament. It is poppy but not too crisp. You can feel the string slightly give on serves and flat shots, and hear the movement on kick serves. It has a nice snap back to it, and you can barely see any movement or notching. It is not too soft and plays well off the baseline. It is live off the baseline and solid on volleys, but not a touch string. It lacks some power, but has a solid feel to it that still gives plenty of power.” 4.5 male baseliner with heavy spin using Prince Tour strung at 55 pounds CP (Prince Premier LT 17)

“This string was very easy to install. This string was very comfortable, had good power and control. I enjoyed play testing this string.” 4.0 male all court player using Prince Premier 105 ESP strung at 65 pounds CP (Prince Tour XP 15L)

“A good all-around string. Enjoyed this one. Comfortable, hangs in there, and really nice to feed balls with! Curious of string and cost. Probably a great cross on a hybrid.” 5.0 male all court player using Babolat Aero Pro Drive strung at 53 pounds CP (Babolat RPM Blast 16)

“Excellent power but had trouble with control. Would use as a cross string with other textured strings. Excellent string snap back as I didn’t have to fix strings after a rally. Compared string tension after 12 hours of play and very little loss of tension.” 4.0 male all court player using Wilson nSix One 95 (18x20) strung at 50 pounds CP (Unique Tourna Black 17)

“From the first time I hit with these strings, I noticed very good power and control, but spin production was only just average to less than average. As I played with them more, they seemed to loosen up and the ball felt like it lingered more and spin improved a bit while power and control stayed relatively the same. I definitely liked the strings more the longer I played with them. Ease of stringing was an added bonus.” 4.0 male baseliner with heavy spin using Dunlop Biomimetic 500 Tour strung at 58 pounds LO (Luxilon Savage 16)

“Solid string with nice power, comfort, and control. String movement was a little more noticeable compared to my normal string. A really comfortable setup that’s easy on the arm. This string could tempt me to switch from my normal poly setup.” 4.0 male all court player using Babolat Aero Pro Drive strung at 58 pounds CP (Tourna Big Hitter Black 7 17)

“Nice soft string. A lot like what I use now. Would buy this as an all-around string.” 4.5 male baseliner with moderate spin using Wilson BLX Five strung at 57 pounds LO (Wilson NXT 17)

“Felt like a soft string to hit with. Lots of control.” 5.0 male all court player using Head Prestige strung at 55 pounds CP (Prince Synthetic Gut 15)

“Very comfortable, soft string bed even with a new, stiffer racquet. Played awesome first five hours, then a noticeable drop in tension. Too spongy, bouncy, less control. Had to dial down swing speed, but still OK.” 4.5 male all court player using Head Prestige strung at 56 pounds LO (Head Intellitour 17)

“Initially, I liked this string. It had a softer feel than my normal string, slightly easier on the arm, wrist, and elbow. However, over time, the string seemed to soften too much, and I noticed a drop off in the ability to generate both pace and spin. After a few hours, this became more noticeable to both myself and my opponent.” 4.0 male all court player using Pro Kennex Ki 15 PSE strung at 63 pounds CP (Pacific XForce/ Pacific Powerline 18/16)

“This is a nice synthetic gut with good playability and power. Unfortunately, as a user of Big Hitter Blue Rough, the string movement that occurs after a short period of play, even at 62 pounds, distracts from my evaluation of this string. Another quality synthetic gut; good playability and power. This string would also do well in a hybrid combination with a poly.” 3.5 male baseliner with moderate spin using Prince Thunder Rip strung at 52 pounds LO (Tourna Big Hitter Blue Rough 17)

“The string played like a multifilament when hit in the sweet spot … good pop and directional control. But, felt like a monofilament when hit off center … stiff and the ball died when coming off the frame. Tension maintenance was good … especial for the hot weather.” 4.0 male all court player using Volkl Organix 4 Super G strung at 59 pounds CP (Volkl V-Twist 17)

“A very comfortable feeling string with lots of control, but it lacks power and pop. Also showed lots of wear and peeling.” 3.5 male all court player using Babolat Pure Storm strung at 58 pounds CP (Gamma TNT 17)

“Overall, a nice string for the average player. Durability not great. Easy to string with. Nice Playability.” 4.5 male all court player using Head Graphene Speed MP strung at 55 pounds CP (Dunlop Black Widow 18)

“Nice string with a good feel, moderate power, and average durability and maintenance of tension. It is consistent with others of this category with a little more pop.” 4.0 male baseliner with moderate spin using Babolat Pure Drive strung at 55 pounds CP (Babolat VS Gut 17)

“Decent string, I would not use.” 4.5 male all court player using Prince Tour strung at 60 pounds CP (Prince Premier LT 17)

Playtester ratings

Ease of Stringing (compared to other strings)
much easier 10
somewhat easier 12
about as easy 14
not quite as easy 2
not nearly as easy 0
Overall Playability (compared to the string played most often)
much better 2
somewhat better 11
about as playable 14
not quite as playable 10
not nearly as playable 1
Overall Durability (compared to other strings of similar gauge)
much better 2
somewhat better 9
about as durable 18
not quite as durable 7
not nearly as durable 2
Rating Averages
From 1 to 5 (best)
Playability (3rd overall) 4.0
Durability 3.3
Power (11th overall) 3.7
Control 3.8
Comfort (3rd overal) 4.1
Touch/Feel (5th overall) 3.9
Spin Potential 3.4
Holding Tension 3.6
Resistance to Movement 3.6

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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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