Category Archives: String Review

String News

As you know I do a lot of string evaluations for myself, my customers and some manufacturers. I do this to have a clear understanding of what a string does at various tensions in various racquets ,and, also in a “controlled” environment!

So, if you ask me for a recommendation my answer will based on data, and, of course some anecdotal evidence. I know most manufacturers try very hard to place the string into the correct category but sometime they simply miss!

There is an ongoing conversation(s) regarding the categorization of polyester based strings relative to racquets and player stature.  This may, for example, look like; “If you use Racquet “X” and are under fourteen (14) years old do not use “XYS” string at tensions higher than 40lbs (18.1 Kilo)”.

Linearity Graph

It is well known that it is very “tricky” to use polyester based string for most younger players that are experimenting with stroke production and still do not have the physical strength to really take advantage of what polyester may offer. For the record I do not recommend it.

Durability is always an issue so when I ask for “playing time” it should be in hours, not days or weeks, but hours. It is a big help to know what portion of those hour are training or playing. It is obvious that one (1) hour of training will be more “destructive” than one (1) hour of tournament play.

The more we know about string the better the choices can be.  It is my imperative that the string matches/enhances the application. Tennis Warehouse, the premier online source for tennis stuff, is also very active in the effort to enlighten players in the selection of the string they order. We can do this!

What do you think?

Ashaway Monogut ZX/ZX Pro – Update

As most of you know I am a big fan of Ashaway Monogut ZX (16g) and ZX Pro (17G) string.  These models are PEEK mono filament strings that resemble polyester strings but these contain no polyester!

Here is the latest PR from Ashaway for your review.

Please let me know if you have any questions, and of course if you want to try this string.

Ashaway, RI – In a recent article on the growth and use of its popular MonoGut® ZX family of monofilament tennis strings, Ashaway Vice President Steve Crandall noted that, “it seems we’ve done something more than simply make a successful product.” While the company’s initial goal was to produce “a synthetic string to rival the performance of natural gut,” MonoGut ZX has emerged as a viable — and healthier — alternative to today’s arm shock inducing polyesters.
Says Crandall, “testing has shown that MonoGut ZX is indeed closer to natural gut in dynamic stiffness than any other synthetic string material. But it’s in the context of the current craze for polyester, and the need for more and more spin, that MonoGut ZX has made the greatest mark. These days everybody wants to improve their ‘up and down’ game, and play like the top pros with ‘heavy balls’ that drop like stones just inside the baseline. To generate that spin they think they need to use those so-called ‘high-tech,’ high-performance polyester strings, and many are paying a high price in impact related injuries.”
Not only do MonoGut ZX and ZX Pro strings generate spin as well as polyester, claims Crandall, but they do so without generating the same arm jarring, injury causing impact shock as the polyesters, and even help players recover from their impact related injuries. In the article, Crandall provides comments and testimony from a number of players and noted stringers on why they switched and continue to use the Zyex® based Ashaway string. These include two rising junior players, Clare McKee and Aditya Srinivasan; expert technician and recent Tennis Industry Racquet Stringer of the Year, John Gugel (; well-known stringer and MRT Geoffrey Jones; and veteran player/stringer Eric Burke (
Crandall reports that while players initially switch to MonoGut ZX (or ZX Pro) for its ability to eliminate their arm pain — “its ‘healing power’ if you will” — they stay with it because it provides other playing benefits as well. “They love the power and control,” writes Crandall, “the ‘softness,’ comfort and overall feel of the string.” 
For example: Of his daughter Clare, stringer/coach Geoff McKee said, “since the switch [to MonoGut ZX], my daughter has had no elbow or wrist problems for four years.” And Clare herself: “I get good pop with these strings and good control. It helps me get more spin, especially on my serve and forehand.”
The parents of East Boys 12-year-old division player Aditya Srinivasan wanted a string that was durable but not a polyester that might injure him. Well-known stringer Geoffrey Jones said, “With Ashaway Monogut ZX Pro they found a soft durable string that almost has the same resilience, softness and safety as natural gut.”
John Gugel says, “The high elongation of the Monogut ZX series almost guarantees no arm issues… It is well known that natural gut is the string to use if there is an arm issue, but now Monogut ZX is an option.” That’s why MonoGut ZX strings have become his “primary strings.” MonoGut ZX, “works and looks like the “other” black string,” he said, “and is a perfect string for the player looking for comfort, spin, power, and durability.”
National level player/stringer/coach Eric Burke said: “Ashaway MonoGut ZX is the ONLY string that provides durability, feel, power, comfort, and tension maintenance. It is by far the best string to use as the crosses for hybrid stringing in those popular new ‘spin-enhancing’ racquets.”
Writes Crandall, “the MonoGut ZX bottom line for us is more than the business bottom line (which is OK, too!); it’s the satisfaction of knowing that we’ve been able to develop a string that is not only fundamentally healthier than the current injury causing polyester offerings, but one that disproves the conventional wisdom and beats those strings at their own game.”
He also notes that many people still want, “More… They want the same ‘healing’ properties as MonoGut ZX in a softer multifilament string bed. So,” he concluded, “stay tuned for some MonoGut ZX Multifilament news in early 2016.”
To read the complete article, ” Users Praise the Playability, Spin Generation, and ‘Healing Power’ of MonoGut® ZX Strings,” visit the Racket Stringing Tips section at
Ashaway Racket Strings are made by Ashaway Line & Twine Mfg. Co., the only U.S. manufacturer of string for squash, tennis, racquetball, and badminton. Operated by the Crandall family since 1824, Ashaway has been making racquet strings since 1949, and is responsible for several important technical innovations. Ashaway has been the Official String of USA Racquetball for more than ten years, and is also the Official String of Professional Tennis Registry. Ashaway Line & Twine Mfg. Co. also makes braided products for medical and industrial applications. For more information visit Zyex is a registered trademark of Zyex Ltd.
For additional product information, contact: 
Ashaway Line & Twine Mfg. Co.
PO Box 549
Ashaway, RI 02804 USA
Tel: (800) 556-7260 (U.S. only) or +1 (401) 377-2221
Fax: +1 (401) 377-9091
Twitter: @Ashaway1824

Head Graphene XT Extreme MPA

As you know Head has made incredible strides in terms of racquet technologies and important players using them!

The racquets I received recently  are the new Head Graphene XT Extreme MPA.  Richard Gasquet, a talented and great player to watch, has been using the “Extreme” model for several years and has been making it into the late rounds at more tournaments!

The bright yellow finish with bright red and black certainly makes a statement!  The black grip is a slight departure from the more usual white synthetic grip used on many racquets.

Head Graphene XT Extreme

Head Graphene XT Extreme

The new model incorporates the ASP technology that allows the racquet to be strung either in a 16 x 19 pattern or a 16 x 16 pattern!  One racquet two string pattern options!  Great idea, I think!


ASP Insert

This model weighs in at 319 grams (11.25 ounces) with a swing weight of 322 (11.36 ounces) with a RDC flex of 60 (compare to 71 for the Babolat Pure Drive).

I installed a new Head string that is not polyester!  The new string is Velocity MLT, a multifilament polyamide (nylon) with about 10.2% elongation.  The string bed stiffness is a comfortable RDC 61 and DT of 38.

If you are considering a new racquet consider this one for sure!

Octave String Natural Gut II

This is a quick follow-up to the original post about this natural gut string.  The racquet was used by several players, all of whom are big hitters, so it took longer than I had expected.  The total hitting time was around five (5) hours  That seems low but it took a beating during those five (5) hours.  I am sure the racquet spent a lot of time in the bag before it was returned to me.

Typical Wear Pattern

Typical Wear Pattern

When the racquet was returned to me the string had broken.

In case you don’t remember this string is produced using sheep serosa not beef as is typical for high end natural gut string.  The first observation is that the finished string is not as “clean” and following that is the string is not as strong as it’s beef counterpart.

The most common comment about this string was the “softness”, and gut like feel.  Both if these are good, of course if you are looking for softness.  Which leads me to believe this string would make a pretty good cross string for those using polyester based main string.  I prefer natural gut for the main string but I am not sure this string is strong enough for that format.



What Shape is Your String In?

Normally when we ask this question it is regarding the “playing” shape, i.e. how is the string bed stiffness, how is the notching, how long has it been in the racquet and some others.

However, this time the question is “what is the shape of your string?”

For many years tennis racquet string has been round.  The round shape is fairly easy to manufacture, using many materials, including multi-filament constructions.  Round strings present a uniform shape that reacts similarly regardless of installation procedure.  Round strings typically provide uniform tensions because there is no “sides” to create additional friction during installation.

The last ten (10) years have seen the increase of polyester, or combinations called co-poly’s, as a tennis racquet string material.  Along with this material came a new, for tennis racquet string, manufacturing process which is essentially extruding a molten material in a nice long continuos strand.  

This process can produce a lot of string in a very short time!  This processing technique can produce very inexpensively to be sure.  It also allows for shapes!  Almost any shape!  All it takes is a “die” of the shape you want as the last thing the string sees before it gets to the cooling tanks or “embossing” wheels.

Make no mistake, however, these strings can be very technical in design and material formulations.  So,if you pay $40.00 for a stringing using one of these strings don’t be surprised.

Back to shapes…

It is common to see three, four, five, six, seven, and even eight sided strings all over the place.  Some of these strings present challenges in terms of installation and, therefore, performance because not only are they shaped they are “twisted”.  Twisting a string creates huge variations in tension unless installed in a controlled way.

A couple of weeks ago a client presented me with a reel of Solinco string that is intended to be similar to the very popular Luxilon ALU Power Rough.  The Solinco is silver, (the image below shows it sort of blue) low elongation, textured string, mostly typical of polyesters.  The unusual property is that the shape of this string is oval!   It should be noted here that Gosen, a major string manufacturer, has made oval shaped strings for years. 

In addition to being oval the string is very aggressively “textured”, actually embossed, which, I believe contributes to the oval shape.  Heres why.  When the string is finishing the processing it is passed through an embossing wheel that creates small indentations in the string.  When this happens the string will flatten out, or become oval. This  process can also contribute to elongation.

Solinco Not Released 16L

Solinco Not Released 16L

If the manufacturer wanted the string to be perfectly round it would subject the string to a pulling process but this is not what I see in the Solinco string, which does not yet have a name.

Initial play tests show significant durability when paired with natural gut.  Control seems to be better than average.  When finished the strings seem to be laying flat against the corresponding cross string which could contribute to string movement.

So…what shape is your string in?

Octave String Natural Gut

For many years natural gut has been the target of many attempts to make it less expensive.  Most of these attempts have not been truly exceptional.

According to the manufacturer, Octave Strings, this natural gut string will sell for $12.00 per set.  Compare this to Babolat, for example, that sells for over $45.00 per set.  Octave Strings natural gut is available in natural color at the moment but a black version will be availalbe according to the manufacturer.

Readers, this is not Babolat, Wilson, Pacific, or Bow Brand quality for sure but it can not be discounted without adequate evlauation.

Octave Strings is the latest, as far as I know, to enter into the tennis string market with a natural gut product. I suspect the string samples I recieved were of the sheep serosa. The string is available in a package of two (2) pieces of 6.5M lengths which leads me to that conclusion, and, was just confirmed by the manufacturer.

The foil and sealed bag packaging is the best I have seen from low cost offerings which gave me hope that this would be a “value” alternative.   Not withstanding what follows this may be an alternative for use in a hybrid format.

The first lab test I do is to determine elongation and this string has very high elongation. It tested at ≈ 10.7%. Compare this to Babolat VS Touch at ≈11%. This is not the same as “dynamic stiffness”.

When I do this testing I have the opportunity to inspect and measure the string diameter. Here is where this string goes way off. The diameter, or gauge, varies a great deal over the length of each piece. The diameter ranged from .050 to .056 and in fact some areas it was difficult to get the string through the grommet. You can, of course, cut off the very stiff end but then you are subjected to fraying ends that will never work!

Octave String tip diameter.

Octave String tip diameter.

I have strung a Babolat Pure Drive with one set of this string and will be reporting more information periodically. One area that is very interesting is that the string is very stable, meaning it is holding tension pretty well so far. The racauet has not been hit with.  It has been seven (7) days since the racquet was strung and the string bed stiffness has decreased by ≈8%. This is very stable behaviour but we will see how it reacts to hitting.

I am going to do some work with the 16 gauge to see how it compares to the 17 gauge keeping in mind that there was a large variation in gauge in the 17 gauge package.

Ocatve Natural Gut 17 Gauge

Ocatve Natural Gut 17 Gauge

Babolat/Octave Visual Comparison

Babolat/Octave Visual Comparison

More later…


Robert Kendrick Joins RQ as String “Analyser”

As most of you know I am a “numbers” person, that is a numerical value is a precursor of performance without the “subjectiveness” of hitters.

However, I am really happy to share with you that Robert Kendrick has agreed to be the “official” Racquet Quest string analyzer. Not only has Robert reached remarkable rankings with the ATP he is spending time developing dedicated juniors.

• Robert Kendrick, Tennis Player and RQ String Analyser
• Robert Bradley Kendrick is an American tennis player. He turned professional in 1999. His career-high singles ranking is World No. 69, achieved in July 2009.
• Born: November 15, 1979, Fresno, CA
• Height: 6′ 3″ (1.91 m)
• Weight: 190 lbs. (86 kg)
• Education: Pepperdine University

Robert Kendrick

Robert Kendrick

The testing procedure will involve strings submitted to RQ by manufacturers, strung in the same racquet at a tension recommended by the manufacturer. The testing will have duration of “till the tension loss makes it unplayable” or until “failure”.

I am looking forward to getting valuable feedback from Robert so I can pass it on to you. Please check in here often to stay on top of string information. Of course if you have any questions of robert please let me know!

%d bloggers like this: