Playtest: Klip Armour Pro 17
By Greg Raven
Klip Armour Pro is a natural gut string with an unusual feature: The gut is completely coated with a hard shell.
Klip says that Armour Pro takes natural gut to the next level, increasing durability and control, while reducing string movement and tension loss. It also states that the technologically advanced coating eases string installation while maintaining the benefits of natural gut.
According to Klip, Armour Pro is for players looking for long lasting, great feeling string.
Armour Pro is available in 16 (1.30) and 17 (1.25) in “Great White” only. It is priced from $32. For more information or to order, contact Klip at 866-554-7872, or visit klipstrings.com.
In the lab
We tested the 17-gauge Armour Pro. The coil measured 40 feet. The diameter measured 1.17-1.21 mm prior to stringing, and 1.15-1.17 mm after stringing. We recorded a stringbed stiffness of 72 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 67 RDC units, representing a 7 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. Armour Pro added 15 grams to the weight of our unstrung frame.
The string was tested for five weeks by 36 USRSA playtesters, with NTRP ratings from 3.5 to 5.5. These are blind tests, with playtesters receiving unmarked strings in unmarked packages. The average number of hours playtested was 29.5.
The coating gives Armour Pro a feel that is not at all like natural gut when stringing. It does reduce problems with unraveling, although it sometimes makes a cracking sound when going around the outside of the frame, and if you pull the crosses too fast, you’ll get burning that makes it much more difficult to pull each successive cross.
One playtester broke his sample during stringing, eight reported problems with coil memory, three reported problems tying knots, and eight reported friction burn.
On the court
Our playtest team rated Klip Armour Pro well above average in Spin Potential and Tension Holding — not surprising for a natural gut string — but it also rated Armour Pro well above average for Durability, a category in which natural gut doesn’t typically do well. In fact, Armour Pro’s Durability rating is just under that of Klip X-Plosive when configured with natural gut in the mains and the poly in the crosses. Our team also rated Armour Pro above average in Power, Control, and Resistance to Movement, for an overall above-average score of the 107 strings we’ve playtested to date.
Five playtesters broke the sample during play, one each at five hours, 11 hours, 17 hours, 18 hours, and 40 hours.
Judging by our playtest results, Klip’s Armour Pro fills a unique market niche: A natural gut string for big hitters. One has to keep in mind when viewing these results that we tested the 17-gauge Armour Pro. Presumably, the durability of the 16-gauge version would be even better.
“This is a really nice string. Very solid and crisp on volleys. It is also comfortable on ground strokes and powerful on serves. I would consider switching to this string!” 4.5 male using Wilson n5 Force strung at 60 pounds CP (Wilson Stamina 17)
“This string has an aramid feel, but, surprisingly, it is responsive, with good touch and control. This string is a wonderful compromise between durability- and playability-based strings.” 5.0 male all-court player using Wilson nSix One strung at 60 pounds LO (Wilson NXT Tour 17)
“This string provides an enjoyable hit. While the overall performance is very good, I am most impressed by the control, durability, resistance to movement and tension maintenance. All other characteristics are average or better, making this an excellent string.” 5.0 male all-court player using Wilson Hyper Pro Staff 6.1 strung at 57 pounds LO (Wilson Sensation 16)
“I’m surprised this natural gut didn’t unbraid during installation. This is a good-playing string with great touch, control and durability.” 5.0 male serve-and-volleyer using Prince O3 Hornet Hybrid Midplus strung at 70 pounds CP (Prince Synthetic Gut with Duraflex 16)
“The crosses are very hard to weave, but this string is otherwise easy to install. I really like the way this plays and lasts. Due to its tough coating, this string holds tension well and the strings don’t move.” 4.0 male baseliner with moderate spin using Fischer Twin Tec 950 FTi strung at 65 pounds LO (Klip X-Plosive 16)
“This string has exceptional control, playability, resistance to movement and durability. It does peel after 18 hours of play.” 5.0 male all-court player using Babolat Pure Control Zylon 360 + strung at 62 pounds CP (Babolat Attraction 17)
“This string excels in nearly every category. I like it so much that I’m still using it!” 3.5 male serve-and-volleyer using Wilson n1 Force strung at 57 pounds CP (Natural Gut 16)
“This is a nice-playing string with good durability. It is a nice teaching string, with good control.” 4.5 female using Head Flexpoint Radical MP strung at 55 pounds LO (Head FXP 16)
“This string provides quite a lot of power, and, due to limited string movement, control. The only downside is the harsh feel.” 4.0 male all-court player using Head Liquidmetal Flexpoint 6 MP strung at 49 pounds CP (Gamma ESP 17)
“Very easy to string. Plays very well from the first hit, but the white coating comes off too easily. While tension maintenance is excellent, it frays too quickly.” 3.5 male baseliner with heavy spin using Prince Triple Threat Hornet strung at 60 pounds CP (Wilson NXT 16)
“This string has excessive coil memory, but scores very well in overall playability. It has great durability, comfort, control, spin potential, touch and power.” 4.0 male all-court player using Wilson Sledge Hammer 3.8 112 (PH) strung at 70 pounds CP (Gamma Live Wire 1730)
“This is the most interesting string I have ever playtested. Initially it seems like a polyester, but the coating chipped off during installation, making me reconsider my earlier definition. During play this string felt pretty good, but it started fraying like natural gut. I tried to break it, but it is quite durable.” 5.0 male all-court player using Head Liquidmetal 2 strung at 60 pounds (Wilson Sensation 16)
“This strings plays well, offering above average comfort and control; however, there is a great deal of tension loss and string movement after 30 hours of play.” 5.0 male all-court player using Head Flexpoint Prestige Mid strung at 60 pounds LO (Head Ultra Tour 17)
“This plays like a polyester with poor resiliency and feel. It does have good durability.” 4.0 male all-court player using Prince Precision Mono strung at 60 pounds LO (Alpha Winning Edge 15L)
“This string plays great, with nice spin. It is, however, much harsher than my current string. I would string it at the low end of the tension range.” 4.0 male all-court player using Pure Drive Team + strung at 52 pounds CP (Natural gut 16)
“This string played with a little poly ping. There is also slight notching. It had average power and slightly above average spin. Great durability and a good ratio of power to control. Overall, a solid choice for those seeking a hybrid which isn’t lacking in any one category.” 5.0 male baseliner with moderate spin using Prince O3 White strung at 55 pounds CP (Prince Polygut 17)
“This is a good all-around string. While it does not excel in any one category, it does not lack anything. This makes for a very easy adjustment and confident tennis.” 4.0 male all-court player using Prince Shark MP strung at 62 pounds LO (Nylon 16)
“During installation the string unbraids too easily. It also frays very quickly during play.” 4.5 male all-court player using Wilson nTour strung at 56 pounds LO (Wilson NXT 16)
“I was happy to finish the playtest. The outer wraps crack during stringing. It also kinks too easily. I was unimpressed with the playability — power was negligible, control and touch were poor. The strings moves a lot, but shows no signs of wear after 20 hours of play.” 4.0 male serve-and-volleyer using Volkl Catapult 7 strung at 58 pounds CP (Natural Gut 16)
“The stringbed feels stiff and boardy for the first two hours of play. It also makes a buzzing sound on mishits. However, it settles nicely, providing good control, crisp serve and volleys, and good depth on ground strokes. After 10 hours of play, the white coating on the string disappeared from the sweetspot, making it appear dirty. Additionally after 10 hours, the stringbed starts to feel mushy, the playability goes down, and the strings start to move.” 4.5 male using Head i.radical OS strung at 60 pounds CP (Head IntelliTour 17)
“This is a good control string, but nothing to write home about. It feels and looks like a multifilament, but is more durable.” 5.0 male all-court player using Prince Graphite Classic MP strung at 55 pounds CP (Prince Synthetic Gut with Duraflex 16)
“I did not like this string because the comfort and touch were below average. However, the durability, control and resistance to movement were adequate.” 4.5 male all-court player using Volkl Tour 9 strung at 58 pounds CP (Wilson Sensation 16)
“This string has a high pinging sound. There is premature fraying within an hour. The playability is average. Due to excessive string movement, the touch and feel decrease quickly.” 5.0 female baseliner with heavy spin using Prince O3 White strung at 55 pounds CP (Prince Lightning XX 16)
“This string has a stiff, polyester-like feel. It plays with very little give.” 4.5 female all-court player using Prince More Control DB 800 MP strung at 60/57 pounds LO (Forten Thin Blend 18/17)
“This string is hard to control. It has good durability and sufficient power. Overall, however, it lacks feel.” 5.5 male all-court player using Wilson nPro Surge strung at 57 pounds CP (Wilson NXT 16)
“This is a decent playing string with nice touch. It lacks the ‘wow’ factor.” 3.5 male all-court player using Head Flexpoint Radical OS strung at 61/59 pounds LO (Forten Aramid Gear/Forten Sweet 15/17)
“This string has good control and tension maintenance; however, it lacked durability and made my wrist sore.” 4.5 female all-court player using Head Protector OS strung at 57 pounds CP (Wilson Sensation 17)
“This string is more durable than my current nylon of choice. I would recommend it to players looking for durability and power.” 5.0 male all-court player using Wilson nSix One strung at 61 pounds LO (Head Synthetic Gut 17)
“This string has an extremely harsh feel. Control was good at first, but I began to notice unpredictable power variations in different parts of the stringbed. There is massive peeling after 2 hours of hard hitting. The manufacturer needs to re-think the coating because I think it makes the string play worse. This string plays very stiff.” 5.0 male all-court player using Wilson nPro strung at 58 pounds CP (Babolat Super Fine Play 17)
“After 40 years of stringing, this is the most difficult installation I have faced. The outer coating appears to be plastic and the resistance pulling the lower crosses was unbelievable. The delicate outer coating also crushes too easily when clamped, and separation occurs between the outer coating and inner core. This appears to be a multifilament string.” 3.5 male baseliner with heavy spin using Prince Thunder Rip OS strung at 62 pounds LO (Unique Tourna Poly Big Hitter 17)
“During stringing and playing the coating comes off. Not only does this string have below average playability and durability, it makes a buzzing sound on most shots. It does have good spin on groundies.” 4.0 male baseliner with moderate spin using Yonex RDX 500 MP strung at 60 pounds LO (Ashaway Crossfire/Wilson Stamina 18)
“Since I usually play with natural gut, I had a hard time adjusting to the ‘plastic’ feel. Eventually, I found good control. Since it is a durable string, I did not like the feel. This would be a good choice for some of my hard hitting juniors.” 5.0 male all-court player using Head Flexpoint Radical MP strung at 54 pounds LO (Natural Gut 17)
“This string plays similar to Kevlar. Tension should be lowered 10 percent.” 5.5 male all-court player using Head Flexpoint Prestige Team strung at 58 pounds CP (Gamma Live Wire 17)
“This is a low-performance string, lacking comfort and control.” 4.5 male all-court player using Head Liquidmetal 8 strung at 58 pounds CP (Gamma Live Wire Professional 17)
“I did not like this string. The playability is below average and the strings move too much. It also notches too easily. While it does hold tension well, it is adequate at best in the power and comfort departments.” 5.5 male all-court player using Wilson n Six One Tour strung at 58 pounds CP (Tecnifibre Polyspin/Prince Synthetic Gut with Duraflex 16L/16)
“The string deforms too much in the tension vice, making it difficult to thread the string through the grommets. The crosses encounter too much friction when pulling them across the mains. This is the most difficult string I’ve ever strung.” 4.0 male all-court player using Head Flexpoint 4 strung at 60 pounds LO (Head FXP 16)
(Strings normally used by testers are indicated in parentheses.)
| EASE OF STRINGING
(compared to other strings)
|Number of testers who said it was:|
|about as easy||18|
|not quite as easy||11|
|not nearly as easy||5|
| OVERALL PLAYABILITY
(compared to string played most often)
|Number of testers who said it was:|
|about as playable||7|
|not quite as playable||22|
|not nearly as playable||0|
| OVERALL DURABILITY
(compared to other strings of similar gauge)
|Number of testers who said it was:|
|about as durable||15|
|not quite as durable||6|
|not nearly as durable||1|
| RATING AVERAGES
From 1 to 5 (best)
|Playability (#10 overall to date)||3.1|
|Control (#5 overall to date)||3.4|
|Resistance to Movement||3.3|
See all articles by Greg Raven
About the Author
Greg Raven is an associate editor for RSI 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 firstname.lastname@example.org, or through Facebook, LinkedIn, and Twitter. He plays tennis five days a week, and is turning into an avid cyclist.
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