Strring Bed Stiffness + Effective Stiffness
Racquet Quest lives by numbers, and these are two (2) of the most important.
This short video will, we hope, help explain why they are important and how they can be used to enhance the player’s performance, and that is “consistency”!
Racquet Quest has several different stringing machine models, and we evaluate different setups on each. It is clear that a “reference” tension across different machines will produce different string-bed stiffnesses.
Take a look at the following video and let us know if you think SBS (string bed stiffness) needs to be the new “reference tension”.
Tecnifibre Fire 300
Tecnifibre Fire 300
The Tecnifibre Fire 300 is another great surprise from Tecnifibre.
Why a surprise? This racquet shows up as a very stiff racquet both “out of plane and in plane”, as you will see in the following numbers.
However, the string pattern and spacing present a “canvas” on which you can create the string bed stiffness of your dreams!
Given the stiffness properties of this racquet, we wanted to test the “limits,” so we used a reference tension of 54, one less than the suggested 55 maximum. Without going through all of the numbers, I can tell you that the Effective Stiffness is 26.7, which is well below our observed pain threshold of 30.0.
All of our demo racquets are strung with MonoGut ZX Pro (PEEK). What you do in terms of string may change that number, but you can be sure the racquet stiffness can be mitigated by your choice of string, tension, and racquet technician.
| Manufacturer | Tecnifibre |
|---|---|
| Racquet Model | Fire 300 |
| Reference Tension | 54 |
| String | MonoGut ZX Pro |
| Machine Used | True Tension Pro |
| String Bed Stiffness - RDC/Units | 45.9 |
| String Bed Stiffness -FlexFour/Pounds | 61.1 |
| String Bed Stiffness - SBS/Pounds | 46 |
| String Bed Stiffness - ERT/Kg/cm | 33 |
| Racquet Flex, RDC/Units | 73 |
| Racquet Flex, FlexFour/Lbs | 46 |
| Racquet - In Plane Stiffness/Lbs/Inch | 537.2 |
| Weight, Grams | 324 |
| Weight, Ounces | 11.3 |
| Balance, mm | 323 |
| Balance, Inch | 12.72 |
| Length, Cm | 68.7 |
| Length, Inch | 27.047 |
| Head Width | 9.98 |
| Head Length | 12.72 |
| Head Area, cm2 | 643.2 |
| Head Area, Sq. Inch | 99.7 |
| Beam Height @ Grip, mm | 25 |
| Beam Height @ Mid, mm | 25.3 |
| Beam Height @ Tip | 24.8 |
| Beam Width @ Grip, mm | 15.5 |
| Beam Width @ Throat, mm | 13.8 |
| Beam Width @ Mid, mm | 11.2 |
| Beam Width @ Tip, mm | 12.2 w/Bumper Guard |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio | .661 |
| Main String Grid Inch/mm | 8.18/207.7 |
| Cross String Grid Inch/mm | 9.87/250.7 |
| Density (% of head filled w/ string) | .794 |
| Average Cross String Space | .513 |
| Average Main String Space | .508 |
| Dynamic Tension, Kp, ERT | 33 |
| Dynamic Tension, Lbs/in | 185.6 |
| First Moment, Nm | .804 |
| Polar Moment | 335 |
| Torsional Stability | 15 |
| Swing Weight, Kg/cm2 | 320 |
| Swing Weight, Ounces | 11.29 |
| Swing Weight Calculated | 338 |
| Power, RDC | 65 |
| Control, RDC | 32 |
| Manueverability, RDC | 73 |
| Power, Calculated | 2352.1 |
| Head Points | 6.46 |
| Head Weight, % | 47.0% |
| Center of Percussion | 21.4 |
| Dwell Time, ms | 7.22 |
| Efective Stiffness - lbs | 26.2 - Flex Four Data |
| K, Lb/In | 134.6 |
| Dynamic Stiffness/Lbs | 369.5 |
| Dynamic Force/Lbs | 141.8 |
| GDR Ratio: static/dynamic | 1.94 |
| Recoil Weight | 161.2 |
| Twist Weight | 240.6 |
| End Weight | 130.9 |
| Tip Weight | 190.3 |
| 9 O'Clock | 97.1 |
| 3 O'Clock | 96.2 |
| Butt End | 129.9 |
| COF, Main | .350 |
| COF, Cross | .262 |
Tecnifibre T-Fight 305 S
Tecnifibre continues to excite us with some very nice racquets. The T-Fight 305 S is the latest iteration and adds to Tecnifibre’s player-category racquets.
Tecnifibre T-Fight 305S
One of the first things you will notice is the depth of the white color! In general, the finish of this racquet is as good as it gets!
Tecnifibre has included “knot locks” on the tie-off holes, so you will see four (4) black “mounds” around the selected tie-off holes. This feature maintains knot tie-off tension and resistance to pulling back into the grommet. An interesting feature.
This 98 square inch racquet incorporates an “open” string pattern perfect for those wanting increased power from the head size. The string bed stiffness can be varied and controlled for players more focused on control.
As with many Tecnifibre performance racquets, the grip is of the “European” shape (flat) as opposed to the more “round” shape used by many brands.
| Manufacturer | Tecnifibre |
|---|---|
| Racquet Model | T-Fight 305 S |
| Reference Tension | 53 |
| String | MonoGut ZX Pro |
| Machine Used | True Tension Pro |
| String Bed Stiffness - RDC/Units | 53 |
| String Bed Stiffness -FlexFour/Pounds | 61 |
| String Bed Stiffness - SBS/Pounds | 40.5 |
| String Bed Stiffness - ERT/Kg/cm | 34 |
| Racquet Flex, RDC/Units | 65 |
| Racquet Flex, FlexFour/Lbs | 40.5 |
| Racquet - In Plane Stiffness/Lbs/Inch | 455.8 |
| Weight, Grams | 332 |
| Weight, Ounces | 11.71 |
| Balance, mm | 324 |
| Balance, Inch | 12.76 |
| Length, Cm | 68.7 |
| Length, Inch | 27.047 |
| Head Width | 9.65 |
| Head Length | 12.91 |
| Head Area, cm2 | 631.0 |
| Head Area, Sq. Inch | 97.8 |
| 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 | .708 |
| Main String Grid Inch/mm | 7.41/188.2 |
| Cross String Grid Inch/mm | 10.32/262.2 |
| Density (% of head filled w/ string) | .728 |
| Average Cross String Space | .543 |
| Average Main String Space | .412 |
| Dynamic Tension, Kp, ERT | 34 |
| Dynamic Tension, Lbs/in | 190.2 |
| First Moment, Nm | .819 |
| Polar Moment | 341.0 |
| Torsional Stability | 16 |
| Swing Weight, Kg/cm2 | 325 |
| Swing Weight, Ounces | 11.71 |
| Swing Weight Calculated | 348.5 |
| Power, RDC | 55 |
| Control, RDC | 45 |
| Manueverability, RDC | 70 |
| Power, Calculated | 2086.8 |
| Head Points | 6.14 |
| Head Weight, % | 47.2% |
| Center of Percussion | 21.1 |
| Dwell Time, ms | 6.43 |
| Efective Stiffness - lbs | 24.3 - Flex Four Data |
| K, Lb/In | 169.9 |
| Dynamic Stiffness/Lbs | 369.5 |
| Dynamic Force/Lbs | 141.8 |
| GDR Ratio: static/dynamic | 1.94 |
| Recoil Weight | 160.8 |
| Twist Weight | 231.5 |
| End Weight | 135.5 |
| Tip Weight | 195.7 |
| 9 O'Clock | 96.2 |
| 3 O'Clock | 94.9 |
| Butt End | 140.1 |
| COF, Main | .348 |
| COF, Cross | .352 |
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