Category Archives: String Review

String Evaluation Program

Racquet Quest, LLC has for years been doing the extensive evaluation of racquets and string for the benefit of our client’s customization requirements.

Now we are making this evaluation “program” available to anyone that wants to dig deeper into the workings of the string in the racquet!

This is serious stuff and requires significant resources but it is worth it!

Please contact us of you would like to take advantage of our evaluation program!

Take a look at the String Evaluation Program!



Looking at the Differences


For the past fifteen (15) years or so, most string discussion centered on polyester. By now, you know our position on polyester, so we won’t go through that again right now. What we will go through right now is the difference(s) in a polyester string!

PET, polyethylene terephthalate, is the standard “material” in the better quality polyester string, so how can there be so many different versions of the same material?

Can you say “additives”? Luxilon has made it part of their brand to use acronyms for materials in each string’s description. ALU, for example, is aluminum, Timo is titanium/molybdenum, and I don’t know what 4G is.

So let’s take a look at the differences in a couple of polyester stings. Shown here are two (2) polyester strings, Luxilon ALU Power and Volkl V-Star. You can see the difference in stiffness between them, the V-Star being “softer,” but what you can’t see is the V-Star package does not say “co-polyester” but instead Co-Polymer!

Polyester? Co-Polyester? Co-Polymer?

We know “co” is two or more and “poly” is many, so how many of anything does any material have in it? We may never know and probably shouldn’t care as long as we have the presented data.

What can we see from this graph?

  • ALU Power reaches 50 lbs quicker (stiffer)
  • ALU Power exhibits good elasticity
  • V-Star is more linear (consistency)
  • V-Star has a greater tensile strength
  • V-Star is softer (takes longer to reach 50 lbs)

How would a player know this by just looking a the package? I am not sure! Adding the word “soft” or “comfort” or “feel” may persuade a player to try the string, but what if a better decision could be made before spending the time and money? 

No graph or chart will take the place of proper racquet stringing and setup, but it may help provide some needed information!

The “Questron” has Arrived!

If you have been following Racquet Quest online and with the podcast, you know we are very fond of data!  In keeping with that “fondness,” we have received our newest testing device, which I have named “Questron.”

During the last week, we have spent time getting Questron set up to do the kinds of testing we think is important for the tennis player, the racquet technician, and anyone else that cares about numbers!

It will be about another week before posting any data because we are “tweaking” some connection points, cycle settings, and refining the data’s graphing.

We have over 400 strings to test; however, we will eliminate many of those strings not relevant to today’s tennis player.

Let us know if there is a string you are particularly interested in. If we have it, we will test it!

Even in the “testing” phase, we are discovering interesting facts about strings that will help us put together the best setup for you!

This is the “base” Questron.  Future versions of this device will incorporate the “Power Potential,” “In-Plane Stiffness,” and “Dynamic Stiffness” testing that is currently done on other equipment.

String. What is important?

The essential function of string in your tennis racquet is to return energy to the ball as it collides with the racquet. It is evident that if there is no string or a broken one, the racquet can not do what it is intended to do, and your shot is going nowhere or worse, everywhere!

There are about thirty (30) string brands, and each brand has about ten (10) different models, and maybe three (3) different colors, so there are nine hundred (900) possible selections! Nine hundred is way too many strings!

You and we need to consolidate string data so we can make the right decision for you, your playing style, and your physical capabilities.

We test every string for elongation, creep, (stability), with a little bit of elasticity data observed. This testing returns our exclusive Power Potential© for each string, and that is the basis of our decision-making process. Naturally, the higher the elongation, the more power the string will return to the ball, and conversely, the lower the power potential, the less power that “can” be generated. You can observe this fundamental by dropping a tennis ball on a concrete floor and then on a strung tennis racquet from the same drop height and see which one bounces the highest.

I use “can” because power, to a great extent, comes from how hard you swing the racquet, which, of course, brings the prospect of overdoing it and subsequent injury! A low power string demands a more powerful swing that involves the entire arm, hips, and legs.

Low power, in the form of a stiff string, has been associated with control, therefore, the increased use of stiff strings. However, with stiffness comes another downside, and that is stability. Stiff strings typically lose tension quickly and need to be changed frequently. So here is the real problem; the string may not be broken, but it is not playing well at all. There is a difference between durability and performance! If your goal is long term performance, a stiff string is not the answer.

What, then, is the answer?

Choose a string with an elongation of 10% or higher! Oh, great! You say. How am I going to know that!

Well, beginning January 1, 2020, I will be posting the power potential of every string we have tested over the years! There are over 500 items on the current list sorted by brand. The color coding is RED if 5% or less, GREEN if 10% or higher, and BLUE for everything else. Note, however, that natural gut is included in this data and will probably not reach the 10% Power Potential© threshold, but is still the best performance string available.  This is due to the dynamic properties of the natural fibers, so, until there is a separate classification gut will be included as is.

A previous post, “What is Soft?” goes into graphical detail.

As new strings are added, some older ones may be deleted because they are no longer manufactured. However, some very old ones may remain due to their “legacy” status. This chart is a preliminary format but will get us map toward the right decision!

Click here to see all the current power potential data.










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?