Category Archives: String

All string information

Strings are made to Work (and wear out)!

If tennis strings are doing what they should, they will wear out!

Your car brakes wear out because they are working!

What happens between the time strings are installed and the time they need to be replaced?

  • Strings are under tension (stress)
  • Strings are subject to fatigue due to hits
  • Strings are subject to frictional notching due to sliding
  • Strings are elastic but will lose tension
  • Strings break

All of the above actions are subject to many variables, of course!

  • String Bed Pattern (16×19, 18×20,,,)
  • Sring Bed Size (90, 95, 98, 100, 110… square inch)
  • Racquet head speed
  • Racquet head angle
  • String wear
  • Environment (wet, dry, hot, cold…)

What does this actually look like, though?

This will give an idea of what a really good wear pattern will look like

after about ten (10) weeks of use.  This is a 17-gauge multifilament in a 98-square-inch head size at a reference tension of 55 pounds (24.9kg).

You may be thinking, “This is not good,” but you may be missing something!

In fact, the COF (coefficient of friction) is greater than when the string was fresh!

COF_ M: 23%, X:  31.5% greater!  This means if you have the nerve (no fear of breaking string), you can continue to play and enjoy the grabbing of the ball by the tiny tentacles that get caught in the ball fuzz.

This will not last forever, though!

COP View

This wear pattern is typical of high-quality multifilament strings.

When making a string selection, think about how long you want the string to perform well, not necessarily how long it will stay in your racquet.

There is a big difference!

If you need some ideas, go to our String Frequency Calculator.  This will give you some high performance stringing cycle recommendations.

Have fun … and use up your string!

Can Your String do This?

Of course, your string can fail, but can it retain the elasticity of this one?

The string is Tecnifibre HDMX, which is in their PolyFusion Series.

This  Tecnifibre HDMX 17Series. This means it is a multifilament string with some fine polyester filaments and a polyurethane binder to hold it all together!

This is a terrific selection for players seeking comfort and a reasonable Power Potential of 8.76!

With a string bed stiffness of 137.8, this racquet will deliver a whopping power index of ≈12.5 when striking the ball!

In this case, the open string pattern contributes to comfort and ball grabbing.

The string exhibits so much elasticity that its long-term performance will not suffer due to premature tension loss and low string bed stiffness.

By the way, the racquet is the latest Head Extreme MPL. This racquet and string combination is a winner!

Players, please remember there are many good string options, so please choose the best combination for you.

We can help!

 

 

 

Yonex V-Core 100

The Yonex V-Core is a great opportunity to review the racquet with IsoSpeed Professional 17 gauge string. If you know anything about the racquet you will know it is a great platform for many player types.

But what about IsoSpeed strings? These strings, and there are a series of them, are unusual in the material and construction, therefore not very well considered!

The string is polypropylene fibers bonded together then stretched and packaged on a stiff molded reel to retain some of the stretching.

If you have seen our previous review on our Questron data you will notice some similarity to natural gut.

Now let’s take a look at the data, shall we?
ManufacturerYonex
Racquet ModelYonex V-Core 100
Reference Tension55
String
IsoSpeed Professional 17
Machine UsedTrue Tension Pro
Static
String Bed Stiffness - RDC41
String Bed Stiffness -FlexFour53
String Bed Stiffness SBS48.6
String Bed Stiffness - ERT31 Kg/Cm^
Racquet Flex, RDC66
Racquet Flex, FlexFour48.6
Racquet - In Plane Stiffness423.7 lbs/In
Weight, Grams321
Weight, Ounces11.32
Balance, mm324
Balance, Inch12.76
Length, Cm68.8
Length, Inch27.08
Head Width9.87
Head Length12.82
Head Area, cm2641.3
Head Area, Sq. Inch99.4
Beam Height @ Grip, mm22
Beam Height @ Mid, mm25.6
Beam Height @ Tip25.5
Beam Width @ Grip, mm16.3
Beam Width @ Throat, mm15.2
Beam Width @ Mid, mm10.3
Beam Width @ Tip, mm11.6
Number of Main Strings16
Number of Cross Strings19
Ratio.649
Main String Grid Inch/mm7.50 / 190.5
Cross String Grid Inch/mm10.15 / 257.8
Density (% of head filled with string).747
Average Cross String Space.529
Average Main String Space.461
Dynamic
Dynamic Tension, Kp, ERT31
Dynamic Tension, Lbs/in173.4
First Moment, Nm.800
Polar Moment328
Torsional Stability15
Swing Weight, Kg/cm2313.0 Kg/Cm^
Swing Weight, Ounces11.094
Swing Weight Calculated337.0
Power, RDC58
Control, RDC41
Manueverability, RDC78
Power, Calculated 2073.9
Head Points5.98
Head Weight, %47.2%
Center of Percussion21.1
Dwell Time, ms7.31
Efective Stiffness - lbs25.3
K, Lb/In131.4
Recoil Weight154.2
Twist Weight233.8
End Weight 130.7
Tip Weight 188.4
9 O'Clock90.5
3 O'Clock89.4
Butt End140.2
COF, Main.392
COF, Cross.321

Here now! Performance T-shirts with a message!

Our new 100% performance fabric t-shirts are already at the World Headquarters and are now available on the website!

Simply click on the “shopping” tab or right here to go to the place to buy your t-shirt and support the “Play Harder not Hurter” mission.

How exciting is that!

Here is a brief preview of the t-shirt message, our guiding principle!

No Underage Polyester, Please

White T-shirt

Bright Pink T-shirt

Purple T-shirt

Each shirt color is available in small/petite (S/P), medium (M), large (L), and Extra Large (XL).

Each shirt is $25.00 If you pick up your shirt at the World Headquarters.

Each shirt is $29.00 If shipped in the United States.

We hope you will join us in keeping all tennis arms and other body parts free of pain.

If you have a special garment you would like our message on, please let us know.  We can do it in the World Headquarters.