Category Archives: Accuracy
Head Prestige Tour 2021
This racquet has the potential to be the hottest new Prestige in a long time. The “Tour” series is not new to the Prestige line but this one has some differences that are meaningful, we think!
This new Tour is a 16×19 string pattern inserted into a 95 square inch hitting area! Compare that to the previous Tour with a 18×19 string pattern in a 99 square inch head(now the new Prestige MP)…so you can see where this one is headed!
Also included in the Prestige Tour is the Auxetic material and construction that is intended to provide a better feeling impact and maybe a little more “energy”. Â The shaft has a slightly different geometry and is a little shorter than some other models, however, the graphics indicate the shaft is “elongated”.
The “box” beam is a relatively constant 22mm from start to finish and is beautifully done in matt black transitioning into the Prestige maroon.
| Manufacturer | Head |
|---|---|
| Racquet Model | Head Prestige Tour 2021 |
| Reference Tension | 53 lbs - 24.0 kg |
| String | Victrex 7718 (PEEK) |
| Machine Used | True Tension Professional |
| ASPS, RDC | 50.0 |
| ASPS, FlexFour | 63.5 |
| Racquet Flex, RDC | 63 - After stringing |
| Racquet Flex, FlexFour | 42.5 |
| Racquet - In Plane Stiffness | 384.6 lbs/Inch |
| Weight, Grams | 336 |
| Weight, Ounces | 11.85 |
| Balance, mm | 326 |
| Balance, Inch | 12.83 |
| Length, Cm | 68.5 |
| Length, Inch | 26.968 |
| Head Width | 9.406 |
| Head Length | 12.78 |
| Head Area, cm2 | 608.9 |
| Head Area, Sq. Inch | 94.4 |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio Cross/Mains | .620 |
| Main String Grid | 7.20 |
| Cross String Grid | 9.125 |
| Density (% of head filled with string) | .695 |
| Average Cross String Space | .464 |
| Average Main String Space | .445 |
| Dynamic Tension, Kp, ERT | 34 |
| Dynamic Tension, Lbs/in | 190.16 |
| First Moment, Nm | .844 |
| Polar Moment | 347 |
| Torsional Stability | 16 |
| Swing Weight, Kg/cm2 | 331 |
| Swing Weight, Ounces | 11.68 |
| Swing Weight Calculated | 357.1 |
| Power, RDC | 53 |
| Control, RDC | 47 |
| Manueverability, RDC | 66 |
| Power, Calculated | 1968.0 |
| Head Points | 5.20 |
| Head Weight, % | 47.6% |
| Center of Percussion | 21.1 |
| Dwell Time, ms | 9.00 |
| Efective Stiffness - lbs | 27.9 |
| K, Lb/In | 160.26 |
| Recoil Weight | 161.61 |
| Twist Weight | 223.59 |
| End Weight | 136.8 |
| Tip Weight | 200.6 |
| 9 O'Clock | 99.5 |
| 3 O'Clock | 101.4 |
| Butt Cap | 134.9 |
What Can String Failure Tell Us?
Well, in the simplest terms, failure tells us it is time to have the request strung! However, there may be subtleties in string failure that can help us in our quest for tennis racquet performance.
Such as?
Is the failure shear related or tensile strength related? Was friction the major contributor to the failure? Where did the failure occur (on the racquet, not the court)? Was the failure during play or in the bag?
Shear-related failure is when the string breaks very near the racquet frame. This failure is called a mis-hit or shank! It is like cutting the string with a pair of scissors!
Shear Failure
Friction Failure
Friction failure is caused by just that, friction! Â Friction is caused by the string moving on each other. That rubbing creates friction and notches the string where it will fail.
If the racquet failed during play and it is not shear-related, the tensile strength of the string was exceeded. If a string has a tensile strength of 120 pounds and the tension is 60 pounds leaving 60 pounds to be used to hit the ball. Some big hitters can generate at least that much force on a solid forehand!
This graph shows the tensile strength of the string to be about 115 pounds. Â Given the movement of this string-on-string, the frictional notching can contribute to relatively early failure based on the hitters force.
This graph shows the tensile strength of the string to be about 155 pounds but it has to travel (stretches) further to reach that force.
So, you can see, with this information we can make better decisions when asked to suggest a string, or strings, for a client!
Bolt 100 v2
Bolt tennis racquets have been around for a few years and we have reported on them in the past, however, the new V2 of the Bolt racquet lineup is very impressive!
If you are not at all familiar with the Bolt technology it is the “Zip Strip” that makes them unique. Â The “Zip Strip” is a carbon fiber component that looks like a miniature tennis racquet cross-section that fits into the sides and top that actually do the “bending” during string and racquet impact!
This “bending” can mitigate harshness associated with very stiff strings or a very stiff racquet!
Before we look at the specifications you can visit the Bolt site for more information.
| Bolt 98L, V2 | |
|---|---|
| Manufacturer | Bolt |
| Racquet Model | Bolt 100, v2 |
| Reference Tension | 57 lbs - 25.9 k |
| String: Main/Cross | Head Reflex |
| Machine Used | True Tension Pro |
| ASPS, RDC | 56 |
| ASPS, FlexFour | 64.5 |
| Racquet Flex, RDC | 64 - After stringing |
| Racquet Flex, FlexFour | 46 |
| Weight, Grams | 313 |
| Weight, Ounces | 11.06 |
| Balance, mm | 337 |
| Balance, Inch | 13.27 |
| Length, Cm | 68.5 |
| Length, Inch | 26.98 |
| Head Width | 9.589 |
| Head Length | 13.13 |
| Head Area, cm2 | 665.1 |
| Head Area, Sq. Inch | 103.1 |
| Beam Width, mm, Shaft, Center, Tip | 24.5, 24.5, 23.8 |
| In Plane Stiffness, Pounds/In | 454 Lbs/In. |
| In Plane Stiffness, Kg/cm | 178.7 Kg/cm |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio Cross/Mains | .642 |
| Main String Grid | 7.37 |
| Cross String Grid | 9.62 |
| Density (% of head filled with string) | .688 |
| Average Cross String Space | .506 |
| Average Main String Space | .461 |
| Dynamic Tension, Kp, ERT | 36 |
| Dynamic Tension, Lbs/in | 201.35 |
| First Moment, Nm | .822 |
| Polar Moment | 350 |
| Torsional Stability | 19 |
| Swing Weight, Kg/cm2 | 331 |
| Swing Weight, Ounces | 11.68 |
| Swing Weight Calculated | 356.6 |
| Power, RDC | 48 |
| Control, RDC | 53 |
| Manueverability, RDC | 66 |
| Power, Calculated | 2183.7 |
| Head Points | 1.42 (negative = head heavy) |
| Head Weight, % | 49.3% |
| Center of Percussion | 21.4 |
| Dwell Time, ms, No Swing | 8.50 |
| Effective Stiffness - lbs | 29.9 |
| K, Lb/In (SBS) RDC | 179.49 |
| Recoil Weight | 157.0 |
| Twist Weight | 234.11 |
| End Weight | 118.7 |
| Tip Weight | 196.1 |
| Total Weight | 314.8 |
| 9 O'Clock | 103.0 |
| 3 O'Clock | 98.9 |
| Butt Cap | 110.3 |
| Total Weight | 312.2 |
Friction v Tension…what wins?
We all know what friction is. Â It keeps our cars from sliding around, it keeps us from slipping and in general makes movement possible!
Friction also plays an important part in the string bed of your tennis racquet. Â Friction between the strings and the ball create friction which in turn creates rotation.
What are, however, some of the downsides of friction in the string bed during, and after, the stringing process?
Friction v Tension
For more detailed information and a graph showing the forces involved go to our membership site, GASP.network, but in the meantime this image will show the frictional forces at work!
This machine tension head will pull the string (blue) in the direction of the center of the racquet support structure instead of directly out the middle of the grommet.
It is obvious that this will create considerable friction and result in lower tension inside the grommet than outside the grommet.
Happy You Year!
Of course, we are all anxious for the new year to get here and erase 2020 from our memory!
We are designating 2021 as the You Year! Â So, Happy You Year!
For the last few years Racquet Quest, LLC has put more emphasis on “custom racquets” and 2021 will see this emphasis extended to “you racquets”!
What exactly does “you racquets” mean? Â It simply means that every racquet that leaves Racquet Quest, LLC is set up for your style of play and personal specifications. Â Yes, even if the racquet is Off-the-Shelf and not a full custom!
Many really good things are happening next year and we are glad you are going to be with us!
Racquet Quest, LLC
