Category Archives: Accuracy
A Hybrid View…Part 2
Three Important Things
When dealing with tennis racquets, there are many significant performance parameters. We are going to list our three (3) most important ones:
- Swing Weight
- Overall Weight
- Effective Stiffness
These particular parameters are based on machine testing, physics, and experience.
- Swing Weight: we refer to this as a dynamic weight, meaning how heavy or light the racquet feels during the swing to the ball.
- Overall Weight: This is normally considered to be the weight found on a scale, electronic, or balance. Weight is your friend if properly associated with your capabilities and stature.
- Effective Stiffness: is a calculable and measurable stiffness of the ball hitting the string as you are holding the racquet and hitting a ball.
Why is it Important?:
- Swing Weight: contributes to power and stability, which contributes to control. A higher swing weight of, say, 320 to 340 will handle most incoming balls with ease. Swing weights of 300 to 319 will be easier to maneuver and require a little more energy from the player to handle aggressive incoming balls.
- Overall Weight: contributes to ease of movement and long play time and must be associated with the stature and style of the player. The heavier racquet will provide more power with less energy expended by the player.
- Effective Stiffness: this is a metric we use to ensure the racquet is within the stiffness range needed by the player. For example, if you come into the World Headquarters of Racquet Quest for the first time with your current racquet and the strings are intact, we can determine the effective stiffness and, based on your satisfaction with the current playability, arrive at a corresponding effective stiffness…not on a reference tension. A range of 24 to 30 pounds is acceptable. Anything over 30 becomes quite stiff and should be avoided by most players.
If you look at our racquet reviews, you will see a lot more than three (3) performance parameters! We believe they are all important, but players should understand the three (3) described here.
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 |
Racquet Quest, LLC



