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!
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
- COP View
- Full String Bed
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).
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!
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.
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 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!
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.
| Manufacturer | Yonex |
|---|---|
| Racquet Model | Yonex V-Core 100 |
| Reference Tension | 55 |
| String | IsoSpeed Professional 17 |
| Machine Used | True Tension Pro |
| String Bed Stiffness - RDC | 41 |
| String Bed Stiffness -FlexFour | 53 |
| String Bed Stiffness SBS | 48.6 |
| String Bed Stiffness - ERT | 31 Kg/Cm^ |
| Racquet Flex, RDC | 66 |
| Racquet Flex, FlexFour | 48.6 |
| Racquet - In Plane Stiffness | 423.7 lbs/In |
| Weight, Grams | 321 |
| Weight, Ounces | 11.32 |
| Balance, mm | 324 |
| Balance, Inch | 12.76 |
| Length, Cm | 68.8 |
| Length, Inch | 27.08 |
| Head Width | 9.87 |
| Head Length | 12.82 |
| Head Area, cm2 | 641.3 |
| Head Area, Sq. Inch | 99.4 |
| Beam Height @ Grip, mm | 22 |
| Beam Height @ Mid, mm | 25.6 |
| Beam Height @ Tip | 25.5 |
| Beam Width @ Grip, mm | 16.3 |
| Beam Width @ Throat, mm | 15.2 |
| Beam Width @ Mid, mm | 10.3 |
| Beam Width @ Tip, mm | 11.6 |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio | .649 |
| Main String Grid Inch/mm | 7.50 / 190.5 |
| Cross String Grid Inch/mm | 10.15 / 257.8 |
| Density (% of head filled with string) | .747 |
| Average Cross String Space | .529 |
| Average Main String Space | .461 |
| Dynamic Tension, Kp, ERT | 31 |
| Dynamic Tension, Lbs/in | 173.4 |
| First Moment, Nm | .800 |
| Polar Moment | 328 |
| Torsional Stability | 15 |
| Swing Weight, Kg/cm2 | 313.0 Kg/Cm^ |
| Swing Weight, Ounces | 11.094 |
| Swing Weight Calculated | 337.0 |
| Power, RDC | 58 |
| Control, RDC | 41 |
| Manueverability, RDC | 78 |
| Power, Calculated | 2073.9 |
| Head Points | 5.98 |
| Head Weight, % | 47.2% |
| Center of Percussion | 21.1 |
| Dwell Time, ms | 7.31 |
| Efective Stiffness - lbs | 25.3 |
| K, Lb/In | 131.4 |
| Recoil Weight | 154.2 |
| Twist Weight | 233.8 |
| End Weight | 130.7 |
| Tip Weight | 188.4 |
| 9 O'Clock | 90.5 |
| 3 O'Clock | 89.4 |
| Butt End | 140.2 |
| 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!
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.
If you have a special garment you would like our message on, please let us know. We can do it in the World Headquarters.









Racquet Quest, LLC


