Comments: Great string for power, feel and durability. The natural is softer, the black is a little stiffer- more like a poly. Takes a few times to find the right tension and you must be very careful while stringing, like a natural gut. I have been stringing racquets for over 40 years both professionally and personally. I am a 3.5 - 4 senior doubles specialist and my personal set up is: Mains - 60 lbs ZX Pro 17 natural Cross- 58 lbs Head Syngut 17 on a Head Speed PWR 115 racquet. The string has a funny sound, but nothing a vibration dampener can't fix! I highly recommend this string!
From: John, 2/11/22

Comments: This is a lot stiffer than Ashaway MonoGut ZX 16 gauge. That 16 gauge is the real deal, and I wish Ashaway would make a 17 gauge version of that.
From:Shripathi, 4/19/21

Comments: A decent string, but had issues with tension maintenance. Firstly I strung it fairly low at about 45 pounds. Had way too much power, and after about an hour I was having to constantly straighten the strings. I cut those out and restrung again, this time around 55 pounds. They were good for about two to three sessions, a mix of singles and doubles, before losing tension and complete loss of control. Good comfort, good spin and good feel, just tension maintenance seemed to be an issue for me. Strung in the Wilson Blade 16x19 v7.
From: Jon, 4/17/21

Comments: I use this string as crosses in a hybrid with natural gut in the mains. It's absolutely amazing. I recently switched from the Wilson Six.One 95 18x20 to the Pure Drive Plus. Unfortunately I first thought I needed the 16 gauge version of this string, in order to tame the inherent power of the Pure Drive Plus. This proved a completely flawed hypothesis. The 16 gauge version deadened the stringbed even at the lowish tensions I was using, and didn't allow ball pocketing, as the gut mains were sliding on the stiffer crosses too much.I decided to use the 17 gauge MonoGut, which I have always loved in my more control-oriented racquets. What an absolute beast! The power and spin are very impressive, increased ball pocketing and dwell time.Of course you need to be a decent player with good accuracy, topspin, and low margins to control your new found power, but if you are, this string will be a game changer, in the crosses. I suggest pairing it with 16 gauge gut in the mains in an open pattern racquet, and 17 gauge in a tighter pattern. I like below recommended tensions, around 50 to 53 pounds in the Pure Drive Plus, even lower in a closed pattern.
From:Attila, 3/19/21

Comments: The cross strings are prone to snapping during the stringing process, I don't understand why. Never a problem with the knots as I've seen reported. I get about halfway done with the crosses and it breaks in a grommet about three crosses up from where I'm at. Two different racquets with new grommets. The one time I was successful in stringing the entire racquet, I loved the feel and pop from these strings. 54 pounds in a 2016 Wilson Pro Staff 97.
From:Todd, 1/27/21

Comments: I tried ZX Pro 17 on a full bed at 50 pounds on my very flexible racquet and I have played with it four times. So far, I have found this string to be not soft at all. Every time I used it, I got bad joint pain. It plays like a very good solid co-polyester and it is firm. I took a break from my previous co-polyester and used a multifilament string for a while which gave me relief from elbow and shoulder pain. Both pains are back using this string.
From:Kaveh, 11/21/20

Comments: I have no idea why anyone would say this is a stiff string that's hard on the body. The Tennis Warehouse testing data backs up Ashaway's data that shows the Zyex material being more flexible than any other synthetic material used in tennis stringing, other than polyolefin, which is about the same. More flexible string material, more comfort. So, if you're finding the string too stiff it means your racquet is strung too tightly, you're not hitting the sweetspot, your racquet itself is too stiff, your racquet is too light, or you're using it with a stiff string in a hybrid. This is a powerful comfortable and durable string. It really has it all, except for a friction coating, which is good because there is nothing to split and wear off. It's very smooth like a polyester string. Just be cautious when tying knots when stringing and avoid nicking it when stringing. This is the string I recommend to everyone. I have tried a good number of other strings and this one is the best next to Babolat VS 17 gut. One particularly nice thing about it is that I don't get any string movement so I don't have to do any fiddling between points. I recently played with Prince ProBlend, which has the stiffest Kevlar mains ever put onto the market. That is a stiff string as is monofilament polyester. It's painful on off-center hits. This Zyex string is not at all painful. I have had wrist soreness from 16 gauge nylon, which is a lot softer than Kevlar but never with the Zyex.
From:Steve, 9/9/20

Comments: This is an update review. The previous review was for the 16 gauge version. Since I saw that they had a thinner gauge, I decided to give it a try. This time I put it on my Yonex VCORE 97 HD. I used Luxilon gut 1.25 on the mains at 45 pounds and the ZX 17 gauge black on the crosses at 42 pounds, strung on Wilson Baraido machine. For some reason, even with this set up, I still got sore tendon on my arm. Last time with the full 16 ZX, it gave me tennis elbow. This string also sawed through my gut in eight hours of play which I don't recommend as a cross string if you are using gut. My full bed of Luxilon gut 1.25 lasted longer cause it still hasn't broken in over 15 hours. I recommend this string for people that never had elbow, wrist, or shoulder issues. It's a really stiff string and doesn't ball pocket as well as other polyesters. I am a USTA 4.5 player and I string test over a hundred different strings so far.
From:David, 6/12/20

Comments: I've had a reel of this I bought on a whim for a long while. I experimented with it in hybrids, as a cross for natural gut and a main for polys and multifilaments. But I never could really groove with it. The feel wasn't anything special, and there is the much talked about ping sound it makes. I went back to my normal setups, full bed natural gut mostly, but sometimes Hyper-G in the mains and a multifilament in the crosses. Then I read some comments on the TT message boards about people's experiences, and realized that I never tried it in a full bed. So I strung up one of my backup sticks, the Head IG Prestige MP, in a full bed at 47 and 45 pounds. What a difference in a full bed it made, comfort, power, spin and pretty good control. I played three full sets and a 10-point tiebreaker and had no arm fatigue or discomfort at all. The sound didn't bother me at all either. Since this bed only has 2.5 hours on it, they should settle for a while. My initial impression was surprisingly very good in a full bed. I used the black version.
From:Pat, 5/18/19

Comments: This is my first impression after hitting with the string for two hours -- My normal hybrid setup is co-poly in the mains 55 lbs and multi or Gosen Sheep Micro crosses 52 lbs. I use the Babolat Pure Control, it's 352 grams strung. I have put ZX full string bed, mains 50 lbs, crosses 47 lbs. It's stiffer than my normal setup, way stiffer. It has the same power than my normal setup, but with more top spin. It doesn't pocket the ball, hence lower directional control on volleys. Basically, I can see it as very resilient poly, though they say it's not. The strings do not move and I think it will last until I cut it out. My normal setup usually lasts around 10 hours due to cross wear in the middle. I guess the string will get its niche of players, but not for people with tendon problems. This one is not kind on your tendons. To round up -- it's just a powerful poly.
From:Nik, 5/6/18

Comments: I'm a serial stringer. I'm fortunate to have a high quality stringer which has allowed me to try many stringing options. I finally said enough of the "cheap" stuff in every combination you can imagine. I strung a full bed of this in my Babolat Pure Drive Plus. Taking head to the Tennis a warehouse review I decided to go up some in tension and string it at 57 lbs, no stretch and medium strength pull. I also let the constant pull sit for 10 seconds each string pull (as instructed). I was very careful and followed all instructions to a T. I played a few hours after and wow! My racquet came alive. I'm a baseliner and will hit groundies all day long. As you may have read in other reviews, this string rewards a big swing. It begs for you to take a full cut at the ball. And when you do, you are seriously rewarded with a heavy paced ball that has some serious spin. It was only when I pulled back from a full forehand or backhand that the ball flew. Not by a mile, but enough for me to know the strings couldn't do their job because I decided to swing easy. Serves popped hard and my kick serve jumped more than usual. Matter of fact, I wasn't so confident in my serve I felt I added about 5-10mph tonight! Volleys were easy and jumped off the racket when placed. I was also able to take a ton off a volley and create some nasty back spin. I rate this string a 9 out of 10 based on one doubles match. I am pretty much a solid 3.5 player with flashes of brilliance to a 4.0 level. No matter what racquet you have, try this string. Be patient when stringing and follow the directions they provide you. You will be greatly rewarded.
From:Matt, 4/25/18

Comments: Used the natural color in my Blade 98 as a cross with Prince Tour XP 17, strung at 47/51 lbs. I am thoroughly confused as to what it is. It feels stiffer than most polys, but has more power than some multis. The only thing lacking is spin, which is unfortunately what my game is heavily based on. But flatter shots, drop shots, and smashes felt great. Serves and ground strokes, not so much. Not too soft on the shoulder, either.
From:Charlie, 2/17/18

Comments: Pretty good spin, but a bit harsh, at least as a full bed. Plus, the sound was quite pingy even with my standard dampener. Too bad, I was hoping to like the string, but I'm off it now. I think tecnifibre Black Code is the better option with similar characteristics.
From:Lenny, 1/19/18

Comments: I can't believe it's not poly! After reading an article titled "Zero Poly Monofilament Trend Gains Momentum" I decided to try this in a full bed because I was tired of arm problems and of poly going dead quickly. At first glance this string looks and feels like poly because it's a smooth monofilament. When playing it offers a perfect comfort balance of characteristics. It provides huge spin without the drawbacks of poly. The other important observation is that the strings always snap back and do not need readjusting at all! My opponents have commented on the heavy ball I can produce with it. Long story short, this is now my permanent setup. Highly recommended!
From:Saul, 12/15/17

Comments: I have this strung on full bed in my Prince racquet. The only string in my experience that combines the power of multi and the spin of poly strings. Highly recommended.
From:Dr. B, 10/8/17

Comments: My stringer had this laying around for over a year and had never used it. He talked me into being his "guinea pig" and I just finished playing with it for the first time. Boy, am I glad I did! I am a 3.5 with a slice backhand and topspin forehand. I had switched from a poly/hybrid setup about six months ago due to bad elbow issues and had become a loyal NXT user, stringing my Prince Textreme Tour 100T at 58 lbs. Really liked the NXT, but this string has it all. Great on touch shots at the net, and loads of spin and control when I swing away. And it doesn't move around which is something that drove me nuts with other synthetics/multi's (the NXT didn't move either). I highly recommend this for any intermediate player looking for excellent control and wanting to avoid painful elbow problems. That said, I can't speak to durability yet since I've only played with it for 1 1/2 hours. We'll see.
From:Brian, 4/22/17

Comments: The very best string I have ever played with and I have been playing my entire life and at reasonably high levels. I recently, just for fun, got my USPTA certification and it was in studying for the exam that I discovered this string.I wish you huge success with this. Every day I play with it I realize how incredibly different this string is. So rare to find the combination of power, control and touch in a single string. Also the tension stability is fantastic. An added bonus -- it is arm friendly and as someone who periodically has battled with arm issues, I feel completely confident with this string. Finally, I have tried the string at 40 lbs and at 51 lbs and what is remarkable is that even at low tensions the control remains very sold with some added power. Good luck!
From:Rocky, 2/13/17

Comments: For advanced rec players: I have tried this string "pre-stretched" and "un-prestretched" in a full bed and in hybrids. As tight as 65 lbs and low as 45 lbs. I would not use this as a full bed, but if you like gut full bed, maybe it is worth a try. However, as a cross in a hybrid with Ashaway Kevlar or a nice natural gut it is fabulous. In a 107" 16x19 I string it at 65 lbs as a cross to Ashaway Kevlar and it lets those kevlar strings slide until the kevlar cuts itself in two. In a 97" racquet I have it strung at 45 lbs in the cross and Ashaway Kevlar at 55 in the mains and it is very similar in play to a poly but with more comfort. As a cross to natural gut it allows the gut to slide "forever" and is really nice for those who have shoulder issues. I prefer the Zyex (cross) gut (main) to full-bed gut. It is a string that there is no "magic number" in tension or prestretch length. It is something you need to play with as a home stringer. Without prestretching it still works fabulous as a cross with unprestretched Ashaway Kevlar. It is a unique string that might fit a wide range of player styles and preferences.
From:Graycrait, 8/16

Comments: Unfortunately, I need to update my previous review. One throbbing forearm and one aching shoulder and elbow later, I must only conclude that this string is not for me. And this in one of the most flexible (PS85) frames ever, leaded up to 371g, and strung at less than 40 pounds. At even 50 pounds in something like an APD, I can envision a 911 call and a trip to the ER. I call this a star-crossed "relationship" string. It's beauty is matched only by its tendency to rip me to shreds.
From:Robin, 7/16

Comments: I usually play with polyester strings, but thought I'd try out this polyketone string. However, the feel was harsh and without much pocketing, which is surprising given the low stiffness value on TW. The sticky, squeaky texture prevented snap-back and the strings got bent out of shape right from the start. Not sure if it is this way only for the black version, but it felt nothing like gut and broke in under 7 hours on my Blade 98 16x19.
From:Neville, 5/16

Comments: I'm a 4.5 player who strings my own racquets (USRSA certified). Tested two sets as cross string with polyester mains and broke another two while tying off the crosses in stringing. While the string is "soft" in terms of its elasticity in play and a good "playability" choice for crosses in a hybrid set, it feels like polyester when stringing i.e. very stiff and spring-like. My experience is consistent with that of another comment in this forum. "The string breaks easily when stringing especially when tying knots." Simply pulling on the string by hand caused the string to snap right at the final tie-off knot on two occasions out of four -- with the result that two half-sets were wasted as well as time in having to redo the cross strings. In play, however, breakage has not been a problem.
From:Neville, 5/16

Comments: This in a full bed is sublime. As a long-time player ever since the boom of the 1970s, I've always looked for a modern-day feeling that replicated the dangerous trampoline effect of the T2000, a launching platform which I craved. A full bed of this in a Wilson ProStaff 6.0 85 at 30 lbs makes the entire racquet face a sweetspot, especially when leaded up to 361 grams. (yes, 30 lbs! try it and you'll never go back I promise.) Perfect for flat drives as well as ridiculous topspin, this string can deliver the concussive pace goods. Is this the birth of the T2001? Or better yet the mythical AeroStaff? Thanks to this string, the sky's the limit, and the 1970s live again.
From:Robin, 4/16

Comments: Really loving this as a cross with Volkl Cyclone 17. That said, it can be a pain to string, given the propensity to breakage. Still, it's nice and slippery, and the feel is amazing. Couldn't ask for more spin or control -- decent power too. Not hard on the arm at all.
From:Ned, 4/16

Comments: Not convinced on this string. It is comfortable, yes, but doesn't have great feel. Power is ok, could use a bit more though. So far it is durable. I guess my problem is, I don't like the way it feels, and I'm not confident with it.
From:Ken, 11/15

Comments: Just strung up a Wilson PS 97LS with Luxilon 4G 17g as the main, and this (MonoGut ZX Pro 17 Black) as the cross. Main at 51 lbs, cross at 53 lbs. Used the 10 second pull (as recommended) on my Gamma 7000es electric stringer. One, and only one, word to describe it: perfect. I will not change a thing; ever! All shots were effortlessly powerful and completely in control. Feel is slightly muted, but just enough feedback to make you smile. I ask for nothing but perfection, and this delivers. Plays less plastic feeling than the same setup with the red. Don't ask me why, just a slight feel difference. One note, the 4g showed slight notching after 8 to 10 hours, heavy notching after 15 hours. Most of the tension is gone, ready to snap, and cut out at 20 hours. 2 racquet rotation; so this was about a month at 3/4 times a week. Previous hybrids include 4G (mains) and Volkl VFeel and Power Fiber II (my daughter uses Cyclone Tour 18); Technifibre NRG2 and X-One; Wilson NXT and NXT Tour (shredded in less than 8 hours), and Babolat VS Touch Natural Gut (16g).
From:Ned, 11/15

Comments: This string is a very good substitute for a slippery poly in the cross. However, it breaks a lot during stringing, especially when tying the knots. I string my own racquets and I will only continue to buy these strings if they reduce the price to under $10. It is very expensive as a cross.
From:Charles, 10/15

Comments: I never thought I would say that a string is better than natural gut, but this truly is better. Monogut ZX is almost as soft as gut, but Monogut is far more durable, especially in the south Florida humidity, and it provides better pop. I initially had my daughter use this string after she had repeated problems with wrist and elbow injuries. Since using this string, she has been injury free for four years and was a national finalist in May. Coaching my daughter, I try a lot of different strings that she gets for free from tournament sponsors, but I haven't found any string as soft, durable, and powerful as Monogut ZX. I string it at 56 pounds for my daughter.
From:Geoff, 9/15

Comments: One of the few hidden secrets in tennis string. I cannot comment on a full bed or use in the mains, but to me, it is a perfect cross. A hard, slick string that is very durable. Plays soft, but yet has great dynamic stiffness. This has been my cross for many months and probably will be for years to come. As long as you are reasonably careful when you string it, you shouldn't have any problems with durability. Gets an A+ in my book.
From:Chris, 8/15

Comments: After upping my training schedule from 5 to 15 hours per week I started to get some shoulder pain from my full poly set up (Tourna BHB7/Golden Set Power Cord). I've since switched to using the Monogut ZX 17 Pro as a cross and the difference in comfort has been astounding. Still fiddling with finding the perfect tension but so far I would say as a cross it provides all the benefits of a poly without the harsh impact. It does add a higher pitched ping to my string bed on impact but I'm getting used to it. I'm an open level tournament player using a Yonex Ai98.
From:Rob, 4/15Comments: My daughter had been a top 10 junior in Florida. At the age of 12, she had to drop to 6 hours a week on court due to wrist and elbow tendinitis. Her growth spurt and joint hyper-mobility worsened the tendinitis. Soft strings helped, but south Florida humidity and damp clay courts shortened the life of gut strings to about 3 hours. Having noticed that Tennis Warehouse rated Ashaway MZX Pro as the softest non-gut string, I had my daughter try it and she liked it right away. She has built up to 24 hours a week on court and has been injury-free since she began using Ashaway MZX Pro 18 months ago. In addition to being the softest non-gut, Ashaway is much more lively than any string that is of comparable durability. I string her racquets at 58 mains, 57 crosses, matching the tension I used for natural gut.
From:Geoff, 8/14

Comments: I am using this string as a cross with Wilson NG 17g, great combo. Highly recommend, but the ZX ripped into the gut too quickly for this to be the go to string bed. It is an interesting string in that TWU list ZX and gut as 2 of the softest strings, but this combo plays crisp, which is what I like about it. Soft on the arm but with crisp power. Gonna try the 16g and see how long that lasts. I think Wilson or Ashaway should sell this Hybrid.
From:Blair, 4/14

Comments: This is a great tweener string. It is as comfortable as natural gut and as durable as polyester. The red one has a softer feel than the natural one. I think a full bed at 55-59 lbs is the ideal tension for this string.
From:Steven, 8/13

Comments: String broke after 10 minutes of play with Solinco Barb Wire 17 as mains at 46 lbs and this string as a cross at 49 lbs. It just snapped after a mishit near the frame. I'm not a big hitter and usually cut strings before they break. I use a Wilson Blade 98S and I was very careful during the stringing. While it worked, the feeling was great, lots of spin from the Barb Wire. I cannot trust this string now.
From:Nick, 10/14

Comments: My daughter had been a top 10 junior in Florida. At the age of 12, she had to drop to 6 hours a week on court due to wrist and elbow tendinitis. Her growth spurt and joint hyper-mobility worsened the tendinitis. Soft strings helped, but south Florida humidity and damp clay courts shortened the life of gut strings to about 3 hours. Having noticed that Tennis Warehouse rated Ashaway MZX Pro as the softest non-gut string, I had my daughter try it and she liked it right away. She has built up to 24 hours a week on court and has been injury-free since she began using Ashaway MZX Pro 18 months ago. In addition to being the softest non-gut, Ashaway is much more lively than any string that is of comparable durability. I string her racquets at 58 mains, 57 crosses, matching the tension I used for natural gut.
From:Geoff, 8/14

Comments: The great thing about these MonoGut strings is that they don't have a coating that wears off. I haven't playtested them, but my longtime tennis partner switched to MonoGut at my suggestion right after it came out and he always plays better with it than with his Head strings (soft polyolefin). He also has had tennis elbow in the past and never has problems with these strings, saying they play better than NRG-2 and other strings he's used. The other thing I have noticed is that they last longer for him than the other strings he's tried. I use Dynamite 16 and have a lot of packs saved up. I like the textured coating on that string, but he and other players didn't like the way it shreds. People who worry about looks will definitely prefer MonoGut because it doesn't have a coating. He is a 4.0 serve and volleyer. I am a low 4.5 baseliner.
From:Rich, 2/14

Comments: My son plays in B18s here in Texas. This is the first string I've found that he doesn't break after a few hours. He has Proline II in the mains at 54 pounds and the ZX in the crosses at 58 pounds. Says the feel is similar to the softer multifilaments we have tried in the crosses.
From:Roger, 8/13

Comments: This is a great tweener string. It is as comfortable as natural gut and as durable as polyester. The red one has a softer feel than the natural one. I think a full bed at 55-59 lbs is the ideal tension for this string.
From:Steven, 8/13

Comments: Hands down, no string compares to this. Best secret in tennis. It's as soft and powerful as gut and as durable as poly. Just be careful not to twist during stringing because it will crease and break like gut.
From:Todd, 9/14

Comments: My daughter had been a top 10 junior in Florida. At the age of 12, she had to drop to 6 hours a week on court due to wrist and elbow tendinitis. Her growth spurt and joint hyper-mobility worsened the tendinitis. Soft strings helped, but south Florida humidity and damp clay courts shortened the life of gut strings to about 3 hours. Having noticed that Tennis Warehouse rated Ashaway MZX Pro as the softest non-gut string, I had my daughter try it and she liked it right away. She has built up to 24 hours a week on court and has been injury-free since she began using Ashaway MZX Pro 18 months ago. In addition to being the softest non-gut, Ashaway is much more lively than any string that is of comparable durability. I string her racquets at 58 mains, 57 crosses, matching the tension I used for natural gut.
From:Geoff, 8/14