Category Archives: Dwell Time
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.
Head Extreme Pro 2026
| 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 |
Snap Back?
For several years, tennis players have been told that some string material will “snap back” during impact with the tennis ball, creating an additional rotational force on the ball. This may be true for some period in some cases, but what if the string does not “snap back”?
Now what?
No Snap Back
If this happens to you, we suggest you do not move the string!
The string is in this position because your stroke sent it there! It just didn’t snap back.
This lack of snap-back creates a very nice string spacing that allows the ball to have greater intrusion into the string bed, more dwell time, and possibly more rotation.
This client strings his racquets frequently due to tension loss that may lead to what we see here. If you want to, or need to, continue playing with this racquet as you see it, try it without moving the string back into position.
The Consumer and SBS
Sting Bed Stiffness (SBS) could be considered alongside performance cars. In the simplest of terms, a high-performance car requires some understanding of what it is going to do; otherwise, you will end up in the trees or worse!
The same with String Bed Stiffness (SBS). If you don’t know what it is going to do, you may end up in the fence!
Why String Bed Stiffness (SBS) matters.
String bed stiffness is a critical performance metric and therefore deserves more attention than it gets in the discussion(s) of string characteristics.
In this video, which is a little “jumpy” at first, you will see the data we collect for every racquet we do. For this discussion, we concentrate on these data:
- Reference Tension
- RDC string bed stiffness
- Flex Four-string bed stiffness
- Racquet Quest SBS (String Sense) stiffness
- Effective stiffness
- Master Tensometer string bed stiffness (kg/cm^)
Racquet Quest, LLC
