Category Archives: Kinesiology
Compare Wilson Shift 99/300 to Shift 99/315
Comparisons are fun and can be informative as one of the steps in selecting a tennis racquet that is right for you!
If you have read the individual reviews of these two (2) racquets you may wonder about some of the numbers.
This comparison table makes it easy to see the properties.
- You will notice very little difference in these racquets’ overall weight and swing weight. Typically tolerances will be in the plus/minus 7-gram range.For example:
- A 300-gram racquet can weigh from 293 to 307 grams.
- A 315-gram racquet can weigh from 308 to 322 grams.
- Different model racquets can be the same weight.
- Same-model racquets can be an ounce different in weight.
So, when multiple racquets are received at the World Headquarters they are characterized to match similar racquets within a model.
Wilson Shift 99/300
After the success of the Wilson Labs version of the Shift technology, Wilson decided to make a retail version. We have received the retail version of the unique racquets and certainly want to share!
Just looking at the racquet, you may ask, “What is unique about it?” Even though the term AI is overused, in this case, it was just used! Some of the concepts of the designers were fed to AI, and it went to work!
Wilson Shift 300
We don’t know the details of the AI prompts, but we do know the very wide throat will accommodate the in-plane flexure of the shaft, which lets the head move downward upon impact and then move back while the ball is in contact with the string, therefore, contributing to “spin.”
This 99-square-inch racquet comes in two (2) versions, the 300-gram and 315-gram “Pro,” with an 18×20 string pattern.
We can feel some flex in the shaft; however, the real test is hitting with this concept, so come in and try the demo. In the meantime, take a look at the numbers.
| Manufacturer | Wilson |
|---|---|
| Racquet Model | Wilson Shift 300 |
| Reference Tension | 58 |
| String | PEEK 7710 |
| Machine Used | True Tension Professional |
| String Bed Stiffness - RDC | 53.0 |
| String Bed Stiffness -FlexFour | 63.5 |
| String Bed Stiffness - SBS | 43.0 |
| String Bed Stiffness - ERT | 35 kg/cm |
| Racquet Flex, RDC | 69 After Stringing |
| Racquet Flex, FlexFour | 43.0 |
| Racquet - In Plane Stiffness | 400.0 Lbs/In |
| Weight, Grams | 330 |
| Weight, Ounces | 11.64 |
| Balance, mm | 325 |
| Balance, Inch | 12.80 |
| Length, Cm | 68.6 |
| Length, Inch | 27.03 |
| Head Width | 9.82 |
| Head Length | 12.75 |
| Head Area, cm2 | 634.0 |
| Head Area, Sq. Inch | 98.3 |
| Beam Height @ Grip, mm | 23.0 |
| Beam Height @ Mid, mm | 24.0 |
| Beam Height @ Tip | 24.0 |
| Beam Width @ Grip, mm | 12.75 |
| Beam Width @ Throat, mm | 12.8 |
| Beam Width @ Mid, mm | 11.1(PWS) |
| Beam Width @ Tip, mm | 13.0(including bumper) |
| Number of Main Strings | 16 |
| Number of Cross Strings | 20 |
| Ratio Cross/Mains | .616 |
| Main String Grid | 7.25 |
| Cross String Grid | 10.81 |
| Density (% of head filled with string) | 71.7 % |
| Average Cross String Space | .494 |
| Average Main String Space | .446 |
| Dynamic Tension, Kp, ERT MasterTensometer | 35 kg/cm |
| Dynamic Tension, Lbs/in | 195.78 |
| First Moment, Nm | .826 |
| Polar Moment | 337.0 |
| Torsional Stability | 17 |
| Swing Weight, Kg/cm2 | 320 |
| Swing Weight, Ounces | 11.29 |
| Swing Weight Calculated | 348.6 (full-length) |
| Power, RDC | 54.0 |
| Control, RDC | 48.0 |
| Manueverability, RDC | 73.9 |
| Power, Calculated | 2191.7 |
| Head Points | 5.67 |
| Head Weight, % | 47.4% |
| Center of Percussion | 20.9 |
| Dwell Time, ms | 8.74 |
| Efective Stiffness - lbs | 30.0 |
| K, Lb/In | 159.87 |
| Recoil Weight | 155.31 |
| Twist Weight | 237.78 |
| End Weight | 133.1 |
| Tip Weight | 194.6 |
| 9 O'Clock | 98.4 |
| 3 O'Clock | 100.6 |
| Butt Cap | 129.0 |
| COF, Main | .396 |
| COF, Cross | .319 |
Pro Stock Limited Reserve
This is a high-performance string that has gone unnoticed for a while and I don’t know why!
Pro Stock Limited Reserve is a string we purchased because it has interesting characteristics that appealed to us however the client base is small. Recently, however, with the number of players that are moving away from a polyester string, this has become a popular alternative!
Pro Stock Limited Reserve
In a word, this plot looks very much like that of natural gut, and whatever you think natural gut is still considered the best performance material for racquet string!
What are we seeing here:
- Linearity, the more linear the string the more consistent (predictable)
- Elongation, at 33.1 mm at 50 pounds
- Elasticity, 71.9 %
- This is the area where the advantages of pre-stretching will be seen.
- The curve will become essentially one line meaning the string returns to a nominal length after stretching.
- Ultimate Tensile Strength, 163.6 pounds to fail (high), @107.2 mm deflection
- Knot strength, @102.4 pounds, and surpasses natural gut in this property.
What we can’t see in the plot is the construction of this multifilament string. Each strand is a thin, flat ribbon of polyolefin material. The ribbons are much like the natural gut.
The plot below is a comparison of natural gut string and is included as a visual to compare to Pro Stock Limited Reserve and show how much natural gut fibers are the same for any string manufacturer. Of course, manufacturing techniques, bonding agents, and coatings make the difference between a good gut and a not-so-good gut!
If you compare the Pro Stock Limited Reserve to natural gut you can quickly see why it may be a good string to try!
Head Radical MP 2023
You have seen the pretty pictures; now see the specs of this new Radical series!
We are starting our property review with the Head Radical MP 2023. The MP version will probably be the most popular due to the very lovely weight and “player” style head size of 98 inches!
Head Radical MP 2023
As you look at the following specifications you may notice the addition of some “numbers”, specifically “beam width”.
We have been taking this number for many years but now believe it is time to expose it to you, the readers.
Briefly, the beam height-to-width ratio contributes to in-plane stiffness which is important for consistent string bed stiffness (SBS).
| Manufacturer | Head |
|---|---|
| Racquet Model | Head Radical MP 2023 |
| Reference Tension | 55 |
| String | MonoGut ZX Pro |
| Machine Used | True Tension Professional |
| String Bed Stiffness - RDC | 53.0 Units |
| String Bed Stiffness -FlexFour | 64.9 pounds |
| String Bed Stiffness - SBS | 51.8 pounds |
| String Bed Stiffness - ERT | 35 Kg/Cm |
| Racquet Flex, RDC | 65 - After stringing |
| Racquet Flex, FlexFour | 44.5 |
| Racquet - In Plane Stiffness | 379.7 lbs/Inch |
| Weight, Grams | 326 |
| Weight, Ounces | 11.50 |
| Balance, mm | 333 |
| Balance, Inch | 13.11 |
| Length, Cm | 68.57 |
| Length, Inch | 27.00 |
| Head Width | 9.63 |
| Head Length | 12.79 |
| Head Area, cm2 | 623.0 |
| Head Area, Sq. Inch | 96.7 |
| Beam Height @ Grip, mm | 21.0 |
| Beam Height @ Mid, mm | 22.5 |
| Beam Height @ Tip | 20.5 |
| Beam Width @ Grip, mm | 12.5 |
| Beam Width @ Throat, mm | 11.5 |
| Beam Width @ Mid, mm | 12.8 |
| Beam Width @ Tip, mm | 12.8 |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio Cross/Mains | .634 |
| Main String Grid | 7.18 |
| Cross String Grid | 9.44 |
| Density (% of head filled with string) | 69.6% |
| Average Cross String Space | .494 |
| Average Main String Space | .449 |
| Dynamic Tension, Kp, ERT | 35 |
| Dynamic Tension, Lbs/in | 195.76 |
| First Moment, Nm | .841 |
| Polar Moment | 347 |
| Torsional Stability | 16 |
| Swing Weight, Kg/cm2 | 331 |
| Swing Weight, Ounces | 11.68 |
| Swing Weight Calculated | 361.5 |
| Power, RDC | 52 |
| Control, RDC | 49 |
| Manueverability, RDC | 66 |
| Power, Calculated | 2101.4 |
| Head Points | 3.15 |
| Head Weight, % | 48.5% |
| Center of Percussion | 21.1 |
| Dwell Time, ms | 8.74 |
| Efective Stiffness - lbs | 29.2 |
| K, Lb/In | 169.87 |
| Recoil Weight | 156.44 |
| Twist Weight | 226.48 |
| End Weight | 126.0 |
| Tip Weight | 197.7 |
| 9 O'Clock | 105.1 |
| 3 O'Clock | 104.7 |
| Butt Cap | 115.6 |
| COF, Main | .416 |
| COF, Cross | .388 |
Racquet Quest, LLC
