Category Archives: Dwell Time

A Wilson RF 01 300 Extended

We want to share the specifications of an extended (70.0mm/27.559) Wilson RF 01 300.

The lengthening process involves removing the staples holding the butt on, which needs to be done carefully for the integrity of the foam pallet, before proceeding with the next steps.

Any time the butt cap comes off a racquet, the first step is to fill the open shaft with a stopper, preferably cotton, to the desired depth for fitting or protection.  If the racquet is “foamed” some of it is removed.

Numerous small details go into the extension we design and print, so we will not go into all of those right now.

The area that will accept the extension is filled with a new two (2) part epoxy made by Starbond.  This epoxy is nearly fully cured after several minutes; however, we prefer to let it cure overnight before proceeding with any other work.

After the curing cycle, the butt cap is installed.  We do not use staples in most cases, only a chemical adhesive.  Staples can easily damage the original foam pallet and the extension if the location is not ideal.

If you make it to the end of this data table, you will find some comparison data.  This data is a glance at what has changed from the original 27-inch length.  This is a specific racquet, so your specifications, if extended, may differ.

This is enough small talk, so let’s take a look at the results of the extension.

ManufacturerWilson
Racquet ModelRF 01 300 Long
Reference Tension56
String
Wilson Duramax NXT
Machine UsedBaiardo
Static
String Bed Stiffness - RDC47
String Bed Stiffness -FlexFour57
Strig Bed Stiffness - SBS50.4
String Bed Stiffness - ERT32
Racquet Flex, RDC62
Racquet Flex, FlexFour50.4
Racquet - In Plane Stiffness450.6
Weight, Grams355
Weight, Ounces12.52
Balance, mm314
Balance, Inch12.36
Length, Cm70
Length, Inch27.559
Head Width9.70
Head Length12.80
Head Area, cm2629.1
Head Area, Sq. Inch97.5
Beam Height @ Grip, mm23
Beam Height @ Mid, mm23
Beam Height @ Tip, mm23
Beam Width @ Grip, mm11.5
Beam Width @ Throat, mm12
Beam Width @ Mid, mm12
Beam Width @ Tip, mm12
Number of Main Strings16
Number of Cross Strings19
Ratio.639
Main String Grid Inch/mm7.42/188.5
Cross String Grid Inch/mm10.56/268.2
Density (% of head filled with string).804
Average Cross String Space.556
Average Main String Space.464
Dynamic
Dynamic Tension, Kp, ERT32
Dynamic Tension, Lbs/in178.9
First Moment, Nm.850
Polar Moment356
Torsional Stability17
Swing Weight, Kg/cm^2339
Swing Weight, Ounces11.96
Swing Weight Calculated350.0
Power, RDC55
Control, RDC41
Manueverability, RDC61
Power, Calculated 2151.9
Head Points11.34
Head Weight, %44.9
Center of Percussion21.5
Dwell Time, ms6.83
Efective Stiffness - lbs26.7
K, Lb/In150.6
Recoil Weight178.85
Twist Weight250.25
End Weight 153.9
Tip Weight 200.4
9 O'Clock95.7
3 O'Clock94.4
Butt End163.6
COF, Main.304
COF, Cross.386
PropertyOriginalExtendedChange %
Overall Weight31935510.1
Swing Weight3103398.5
Length27.027.552.0
Power Calculaton1892.82151.912.0
Recoil Weight149.4178.816.4
Twist Weight224.87250.210.1

 

 

 

What About Me?

A lifetime dedicated to racquet technology and innovation

For more than five decades, I have been immersed in the world of tennis racquet and string design, manufacturing, and performance optimization. As the owner of Racquet Quest, LLC, I’ve combined deep technical expertise with hands-on innovation to set new benchmarks in racquet customization, diagnostics, and stringing.

My journey has been defined by a relentless pursuit of precision and performance—whether with professionals, college,  junior tournament players, in the lab, or in front of an audience, sharing knowledge with peers.

Advanced diagnostic technology

At Racquet Quest, technology and science drive results. I’ve integrated some of the most advanced diagnostic equipment available, alongside proprietary systems I’ve developed, to provide unmatched insights into racquet and string performance:

  • True Tension Stringing Machines – pioneering distortion-free stringing
  • Babolat Racket Station & Wilson Baiardo Stringing Machines – industry-leading accuracy
  • Babolat RDC (Racquet Diagnostic Center) – comprehensive racquet analysis
  • Questron proprietary string testing equipment – measuring ultimate tensile strength, stress/strain, knot strength, and more
    • Three-string comparative graphing tools – side-by-side performance visualization
    • Flex, In-Plane, and String Bed Stiffness devices – quantifying structural dynamics
    • Custom portable SBS device – portable precision testing

By combining these tools, I’ve been able to capture and refine the delicate balance between tension, elasticity, and structural integrity, pushing racquet performance beyond traditional standards.

Innovation in design and customization

Innovation has always been central to my work. Some of the highlights include:

  • Development of the Perfect Pallet grip system with a custom three-piece anti-vibration design
  • Expertise in Special MakeUp (SMU/Pro Stock) racquets for elite players
  • Custom racquet extensions and modifications tailored to individual needs
  • Proprietary software solutions for collecting and analyzing racquet and string performance data

These advancements have helped players—from juniors to professionals—experience greater consistency, comfort, and control on court.

Experience on the global stage

  • My expertise extends well beyond the workshop:
    • 50 years in racquet and string design and manufacturing
    • Professional event stringing services for several years at major tournaments
    • Seminar presenter for 12+ years, sharing expertise with players, coaches, and technicians
    • Delivered the acclaimed session “Understanding String” at the 1994 Super Show in Atlanta, hosted by the United States Racquet Stringers Association

This combination of hands-on service and educational leadership has helped shape best practices across the racquet service community.

Media and knowledge sharing

I believe that expertise should be shared widely. To that end, I’ve created multiple platforms to bring racquet knowledge to players and enthusiasts worldwide:

  • RacquetQuest.tennis – a hub for insights and resources on racquet technology
  • Racquet Quest Podcast, Podcastini, and Podcast Midi – covering everything from string science to on-court trends

Through these channels, I aim to make the science of racquets accessible to every level of the game.

Tennis continues to evolve, and so does racquet technology. At Racquet Quest, I remain committed to research, testing, and innovation that give players an edge while deepening their understanding of how equipment shapes performance.

Whether stringing for professionals, customizing for serious competitors, or educating the next generation of racquet technicians, the mission remains the same: deliver precision, performance, and passion through technology.

POP…what is it and, really, what is it?

 Why Dwell Time Works for “Pop”

  • “Pop” = Ball Rebound Speed, which is heavily tied to how quickly the ball leaves the stringbed.

  • A shorter dwell time generally means higher ball exit velocity—the racquet “punches” the ball out faster, which feels like more pop but less “energy.”

  • Conversely, longer dwell time gives a “softer” feel, with more ball cupping and potentially more control or spin, but there is a less immediate rebound.


 Advantages of Using Dwell Time

  • ✅ Objective & Measurable: Unlike “feel,” which is subjective,  We calculate dwell time for every racquet we do.

  • String-agnostic: Since you’re isolating the moment of contact, it’s less influenced by the brand, gauge, or material, especially when averaged over several hits.

  • Independent of Vibration Dampers: Since dwell time happens before stringbed vibration even knows what is happening, dampers (which affect post-impact sound/feel) are irrelevant.

 Things to Consider

  • Dwell time is still influenced by tension, racquet stiffness, swing speed, and impact location.

  • It might not fully capture the subjective “pop” some players describe, because that sometimes includes auditory feedback or even rebound height perception.

However, as a technical baseline, dwell time is an excellent metric for quantifying “pop” without getting bogged down in subjective or brand-dependent language.

We have been calculating dwell time for many years, so below we will associate a frequency (sound) with string bed stiffness so you can hear what “Pop” sounds and feels like!

Dwell Time:  5.677 ms.

String Bed stiffness:

Flex Four=71.1

RDC=74

ERT=42



Dwell Time: 6.829

String Bed Stiffness:

Flex Four=60.0

RDC=47.0

ERT=33.0



Dwell Time:  7.803

String Bed Stiffness:

Flex Four=57.0

RDC=36.0

ERT=27.0

Dwell Time:  7.803