Category Archives: True Tension
Wilson Defyer Pro 98 v1.0
The Wilson Defyer product release is one of the most unusual and talked-about releases in a long time!
The initial prototypes were “Python”; the next iteration was “Redline”; and the newly released, and final, version is the “Defyer”.
The Defyer is available in 98 and 100 square inch head sizes. The string pattern is 16×20 with spacing that allows for a broad range of string bed stiffnesses to suit most play styles.
The head shape and geometry are familiar; however, there is some “sculpting” going on that adds something to the overall appearance.
While appearance is important, the real stuff is in the numbers, and we have those right here…
After you go through the numbers, stick around for some additional highlights that may go unnoticed.
| Manufacturer | Wilson |
|---|---|
| Racquet Model | Defyer Pro 98 v1 |
| Reference Tension | 56 |
| String | MonoGut ZX Pro |
| Machine Used | True Tension Pro |
| String Bed Stiffness - RDC | 47 |
| String Bed Stiffness -FlexFour | 61 |
| Strig Bed Stiffness - SBS | 51.7 |
| String Bed Stiffness - ERT | 33 |
| Racquet Flex, RDC | 65 |
| Racquet Flex, FlexFour | 51.5 |
| Racquet - In Plane Stiffness | 474.4 |
| Weight, Grams | 325 |
| Weight, Ounces | 11.46 |
| Balance, mm | 327 |
| Balance, Inch | 12.87 |
| Length, Cm | 68.7 |
| Length, Inch | 27.047 |
| Head Width | 9.80 |
| Head Length | 12.76 |
| Head Area, cm2 | 633.7 |
| Head Area, Sq. Inch | 98.2 |
| Beam Height @ Grip, mm | 22.5 |
| Beam Height @ Mid, mm | 23.8 |
| Beam Height @ Tip | 22.5 |
| Beam Width @ Grip, mm | 18 |
| Beam Width @ Throat, mm | 13.8 |
| Beam Width @ Mid, mm | 11 |
| Beam Width @ Tip, mm | 13.6 (w/Bumper Guard) |
| Number of Main Strings | 16 |
| Number of Cross Strings | 20 |
| Ratio | .614 |
| Main String Grid Inch/mm | 7.56/192.2 |
| Cross String Grid Inch/mm | 10.41/264.4 |
| Density (% of head filled with string) | .768 |
| Average Cross String Space | .520 |
| Average Main String Space | .453 |
| Dynamic Tension, Kp, ERT | 33 |
| Dynamic Tension, Lbs/in | 184.57 |
| First Moment, Nm | .819 |
| Polar Moment | 333.0 |
| Torsional Stability | 16 |
| Swing Weight, Kg/cm2 | 317 |
| Swing Weight, Ounces | 11.18 |
| Swing Weight Calculated | 347.5 |
| Power, RDC | 54 |
| Control, RDC | 44 |
| Manueverability, RDC | 74 |
| Power, Calculated | 2044.1 |
| Head Points | 5.20 |
| Head Weight, % | 47.6% |
| Center of Percussion | 20.9 |
| Dwell Time, ms | 6.83 |
| Efective Stiffness - lbs | 27.3 |
| K, Lb/In | 150.64 |
| Recoil Weight | 151.88 |
| Twist Weight | 233.42 |
| End Weight | 134.4 |
| Tip Weight | 194.4 |
| 9 O'Clock | 97.4 |
| 3 O'Clock | 94.8 |
| Butt End | 137.4 |
| COF, Main | .382 |
| COF, Cross | .315 |
Something with tennis racquets that is important to us is “serviceability”. The Defyer, like most Wilson racquets, has a nice grommet system that protects the string from “court contact” damage, and is “aerodynamic” in shape.
The grip pallet system is another matter, however, and makes grip size and shape modifications difficult, if not impossible. So, when you are making a purchasing decision, be sure you are choosing the correct grip size. This pallet system is not unique to the Defyer, but the Defyer is in the category of “customizable” racquets. Don’t plan on much grip customization!
Head Extreme Pro 2026
If you are thinking of a new 98 square inch high-performance racquet, don’t make a decision until you try this one!
This one is the new Head Extreme Pro for 2026, with a beautiful cosmetic upgrade and material enhancements that improve performance.
Something that you may not notice but is very good is the elongated cross-string holes in the twelve (12) central cross strings’ location. This design increases the effective hitting area by a couple of inches without increasing the head width. This is not unique to the Extreme Series, but it does not show up in the Speed or Gravity series.
| Manufacturer | Head |
|---|---|
| Racquet Model | Head Extreme Pro 2026 |
| Reference Tension | 55 |
| String | MonoGut ZX Pro |
| Machine Used | True Tension Pro |
| String Bed Stiffness - RDC/Units | 50 |
| String Bed Stiffness -FlexFour/Pounds | 63 |
| Strig Bed Stiffness - SBS/Pounds | 43.5 |
| String Bed Stiffness - ERT/Kg/cm | 34 |
| Racquet Flex, RDC/Units | 67 |
| Racquet Flex, FlexFour/Lbs | 43.5 |
| Racquet - In Plane Stiffness/Lbs/Inch | 493.6 |
| Weight, Grams | 330 |
| Weight, Ounces | 11.64 |
| Balance, mm | 323 |
| Balance, Inch | 12.72 |
| Length, Cm | 68.6 |
| Length, Inch | 27.008 |
| Head Width | 9.56 |
| Head Length | 12.87 |
| Head Area, cm2 | 623.8 |
| Head Area, Sq. Inch | 96.7 |
| Beam Height @ Grip, mm | 20.5 |
| Beam Height @ Mid, mm | 23.3 |
| Beam Height @ Tip | 22.4 |
| Beam Width @ Grip, mm | 15.7 |
| Beam Width @ Throat, mm | 134.0 |
| Beam Width @ Mid, mm | 11.5 |
| Beam Width @ Tip, mm | 13.9 w/Bumper Guard |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio | .625 |
| Main String Grid Inch/mm | 7.21/183.1 |
| Cross String Grid Inch/mm | 9.63/244.6 |
| Density (% of head filled w/ string) | .728 |
| Average Cross String Space | .507 |
| Average Main String Space | .457 |
| Dynamic Tension, Kp, ERT | 34 |
| Dynamic Tension, Lbs/in | 190.2 |
| First Moment, Nm | .819 |
| Polar Moment | 331.0 |
| Torsional Stability | 14 |
| Swing Weight, Kg/cm2 | 317 |
| Swing Weight, Ounces | 11.18 |
| Swing Weight Calculated | 344.3 |
| Power, RDC | 55 |
| Control, RDC | 48 |
| Manueverability, RDC | 75 |
| Power, Calculated | 2074.2 |
| Head Points | 6.30 |
| Head Weight, % | 47.1% |
| Center of Percussion | 20.9 |
| Dwell Time, ms | 6.62 |
| Efective Stiffness - lbs | 26.4 - Flex Four Data |
| K, Lb/In | 160.26 |
| Dynamic Stiffness/Lbs | 369.5 |
| Dynamic Force/Lbs | 141.8 |
| GDR Ratio: static/dynamic | 1.94 |
| Recoil Weight | 155.24 |
| Twist Weight | 226.4 |
| End Weight | 134.9 |
| Tip Weight | 193.9 |
| 9 O'Clock | 97.5 |
| 3 O'Clock | 95.8 |
| Butt End | 136.9 |
| COF, Main | .348 |
| COF, Cross | .352 |
Big 10 Tennis Player of the Week.
Jack Anthrop has been playing extraordinary tennis for a long time and was recently named Big 10 Tennis Player of the Week after an impressive outing in Dallas!
The link below will take you to the Ohio State post; however, I want to share some of the things Jack has done to secure the game he has.
Jack uses a Head Speed SMU racquet. The head size is 96 square inches and has a swing weight of 333 kg/cm^. This inertia couples with the overall weight of 352 grams (12.4 oz) to create stability and power.
Jack uses MonoGut ZX Pro natural at a reference tension of 56 pounds and string bed stiffness of 60 pounds. This creates a dynamic stiffness of 393.6 PPI.
Jack has been using Ashaway MonoGut ZX Pro since the age of 9! Yep, that’s right, age 9! MonoGut ZX and ZX Pro material is PEEK, a unique string that offers outstanding comfort, feel, and power with better durability than some other materials.
It is our position that more players of any level should consider MonoGut ZX or ZX Pro (thinner). It really just makes sense…just ask Jack, Big 10 Men’s Tennis Player of the Week!
Let us know if you have questions about Jack’s racquet or string. We have been working with Jack since age 9, and we would like to share what we can to help achieve your tennis goal(s).
Thank you, Head and Ashaway, for your continued support!
mens-tennis-anthrop-earns-big-ten-player-of-the-week
Congratulations, Jack, your new Head Speed SMU’s are on the way.
More Face Time?
We have found a good format for our video content creation and presentation.
After trying several highly rated and pricey options, we have settled on QuickTime, iMovie, and YouTube.
- Quick Time for recording the video
- iMovie for editing (which we want to keep to a minimum)
- YouTube for presentation
Now there is an “RQ on YouTube” button on the home page menubar! Right now, this is at the very right side of the menu, so please use it to get to our YouTube channel easily.
Thank yo for joining us for “more face time”!




Racquet Quest, LLC


