Category Archives: Evaluation
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 99/315 Pro
The Wilson Shift has introduced a new movement in racquet design, and the Shift 99/315 Pro rounds out the two (2) racquet series for now!
If you read the review of the 99/300 Shift, you have a good idea about the concept: on the impact, the ball moves the head down, and before the ball can leave the strings, the head moves up!
It is like you are swinging from low to high! It sounds simple, but there is more to it than that.
| Manufacturer | Wilson |
|---|---|
| Racquet Model | Wilson Shift 99/315 Pro |
| Reference Tension | 50 |
| String | Babolat Xalt 130 |
| Machine Used | Babolat Racquet Station |
| String Bed Stiffness - RDC | 60.0 |
| String Bed Stiffness -FlexFour | 64.6 |
| String Bed Stiffness - SBS | 45.0 |
| String Bed Stiffness - ERT | 38 kg/cm |
| Racquet Flex, RDC | 70 After Stringing |
| Racquet Flex, FlexFour | 45.0 |
| Racquet - In Plane Stiffness | 383.6 Lbs/In |
| Weight, Grams | 338 |
| Weight, Ounces | 11.92 |
| Balance, mm | 321 |
| Balance, Inch | 12.64 |
| Length, Cm | 68.6 |
| Length, Inch | 27.03 |
| Head Width | 9.79 |
| Head Length | 12.74 |
| Head Area, cm2 | 632.1 |
| Head Area, Sq. Inch | 98.0 |
| 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 |
| Beam Width @ Tip, mm | 13.0(including bumper) |
| Number of Main Strings | 18 |
| Number of Cross Strings | 20 |
| Ratio Cross/Mains | .692 |
| Main String Grid | 7.13 |
| Cross String Grid | 10.44 |
| Density (% of head filled with string) | 76.0 % |
| Average Cross String Space | .522 |
| Average Main String Space | .396 |
| Dynamic Tension, Kp, ERT MasterTensometer | 38 kg/cm |
| Dynamic Tension, Lbs/in | 212.54 |
| First Moment, Nm | .832 |
| Polar Moment | 341.0 |
| Torsional Stability | 17 |
| Swing Weight, Kg/cm2 | 324 |
| Swing Weight, Ounces | 11.43 |
| Swing Weight Calculated | 346.3 (full-length) |
| Power, RDC | 49.0 |
| Control, RDC | 51.0 |
| Manueverability, RDC | 74.0 |
| Power, Calculated | 2244.1 |
| Head Points | 6.93 |
| Head Weight, % | 46.8% |
| Center of Percussion | 21.0 |
| Dwell Time, ms | 5.94 |
| Dwell Time, Spin, ms | 8.21 |
| Efective Stiffness - lbs | 32.3 |
| K, Lb/In | 192.31 |
| Recoil Weight | 161.30 |
| Twist Weight | 242.30 |
| End Weight | 135.9 |
| Tip Weight | 193.8 |
| 9 O'Clock | 98.2 |
| 3 O'Clock | 99.0 |
| Butt Cap | 130.4 |
| COF, Main | .396 |
| COF, Cross | .319 |
A Players Perspective
We are really happy to have Jason Harne join us to review and add his comments on tennis racquets and tennis strings!
I think you will agree that Jason will be a great addition to racquetquest.com based on the following tennis bio:
Jason Harne – Tennis
- Pro tennis – futures tournaments and satellites
- Stirling University, Scotland. One of the first players to be awarded the British Universities Tennis Bursary Colors Award (equivalent to All-American)
- International home nations tournament, representing Scotland, player of the tournament award.
- England county cup, division one, representing Yorkshire County.
- Spain and UK, national league tennis
- High Point University, Big South Conference, 22-2 record.
- U21 guardian direct British futures, national champion, and fastest UK serve.
- Teaching pro, UK and Spain, high-performance players
This is very impressive but the most important component for us, and you, is Jason’s incredible interest in new things! Jason is willing to try, and honestly comment on, any performance tennis equipment.
Jason will be commenting on the new Wilson Shift series later this week.
Please leave a comment or question for Jason.
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 |
An Inside Look at String Evaluation
In this series, we will look at the various characteristics of tennis string without the tennis racquet!
Racquet Quest evaluates every string we use plus strings submitted from other sources. These evaluations are “No Prep” and “Prep”, which simply means the Prep string has been pre-stretched in the entire length. It has not been through a tennis racquet…yet!
The following images represent a string that has not been “prepped.” After these plots are fully understood we will do the same string in the”prepped” format to see if there is a difference.
Ultimate Tensile Strength
What we notice immediately is the string is very “soft” as seen in the deflection of 47.8 mm to reach 50 pounds. Also, the elasticity, the ability to recover to the original length, is fairly low.
The area under the 50-pound and 47.8 mark is the stress/strain curve that shows how the string behaves in three (3) cycles. The load and number of cycles can be changed.
The long run (linearity) from the 50-pound mark to failure is quite good and suggests consistency.
The UTS, the ultimate tensile strength, of 127.1 pounds is good for this thin string.
The following plot shows the knot strength of this string.
Knot Strength
This plot is overlayed on the previous image so a quick comparison can be made. It is common for knot strength to be lower than un-knotted string. Knot strength is primarily important to the person tying the knot. Knots rarely fail after they are successfully tied. Pulling a knot too tight or jerking can break a knot.
This plot says to us that this string needs to be handled carefully when it comes to knots! We would expect a knot strength of at least 80 pounds for typical monofilament strings, however, if this string exhibits extraordinary play characteristics anyone can learn to tie the knots!
Based on this information we would suggest this string for a player looking for extraordinary comfort, power, and relatively short life!
Racquet Quest, LLC
