Category Archives: Inspiration
Head Gravity Tour 98-Pre Release Version
If you have listened to our latest podcast, you will know a little about the new Head Gravity Tour 98, to be released in January 2025!
The difference between what you may see online and what Racquet Quest, LLC has is we have taken a raw racquet and applied the desired specifications to it.
We see this as a racquet suitable for many playing styles and levels, so we began with a swing weight of 321 and an overall weight of 327.
After Stephanie’s brief video about her reactions to this Gravity Tour 98 racquet, we will return to associate her comments with the numbers in our review! Wouldn’t that be fun?
In Stepahines’ video, she adds several years to the age of her Gravity MP, calling it 2003. Actually, it is 2023.
Now, here’s Stephanie!
Now, the numbers…
| Manufacturer | Head |
|---|---|
| Racquet Model | Head Gravity Tour 98 PreRelease |
| Reference Tension | 56 |
| String | PEEK 7710 |
| Machine Used | True Tension Pro |
| String Bed Stiffness - RDC | 49 |
| String Bed Stiffness -FlexFour | 57.7 |
| Strig Bed Stiffness - SBS | 43.7 |
| String Bed Stiffness - ERT | 33Kg/Cm^ |
| Racquet Flex, RDC | 57 |
| Racquet Flex, FlexFour | 44.8 |
| Racquet - In Plane Stiffness | 373.1 |
| Weight, Grams | 327 |
| Weight, Ounces | 11.53 |
| Balance, mm | 325 |
| Balance, Inch | 12.80 |
| Length, Cm | 68.6 |
| Length, Inch | 27.008 |
| Head Width | 9.827 |
| Head Length | 12.724 |
| Head Area, cm2 | 633.6 |
| Head Area, Sq. Inch | 98.2 |
| Beam Height @ Grip, mm | 21.0 |
| Beam Height @ Mid, mm | 22.0 |
| Beam Height @ Tip | 22.0 |
| Beam Width @ Grip, mm | 10.7 |
| Beam Width @ Throat, mm | 11.3 |
| Beam Width @ Mid, mm | 10.5 |
| Beam Width @ Tip, mm | 12.1 |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio | .650 |
| Main String Grid Inch/mm | 7.50/190.5mm |
| Cross String Grid Inch/mm | 10.38/263.6 |
| Density (% of head filled with string) | .785 |
| Average Cross String Space | .546 |
| Average Main String Space | .464 |
| Dynamic Tension, Kp, ERT | 33 |
| Dynamic Tension, Lbs/in | 184.57 |
| First Moment, Nm | ,818 |
| Polar Moment | 335 |
| Torsional Stability | 14 |
| Swing Weight, Kg/cm2 | 321 |
| Swing Weight, Ounces | 11.32 |
| Swing Weight Calculated | 345.4 |
| Power, RDC | 51 |
| Control, RDC | 47 |
| Manueverability, RDC | 73 |
| Power, Calculated | 1814.8 |
| Head Points | 5.83 |
| Head Weight, % | 47.3% |
| Center of Percussion | 21.1 |
| Dwell Time, ms | 6.69 |
| Efective Stiffness - lbs | 26.3 |
| K, Lb/In | 157.05 |
| Recoil Weight | 157.80 |
| Twist Weight | 236.02 |
| End Weight | 132.2 |
| Tip Weight | 192.1 |
| 9 O'Clock | 91.6 |
| 3 O'Clock | 90.8 |
| Butt End | 143.1 |
| COF, Main | .378 |
| COF, Cross | .386 |
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!
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.
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!
T-Shirts with a Message!
Just in case you can not make it to Racquet Quest’s World Headquarters, we are posting our T-shirt loop here so you all can see it!
If you can’t make it to the World Headquarters you can pick up your “T-Shirts with a Message” here!
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 |
Racquet Quest, LLC
