Category Archives: Stress/Strain
Play Better Longer
For many years, we have been testing all racquets for string bed stiffness, effective stiffness, flexural stiffness, in-plane stiffness, and about any other stiffness you can imagine.
Throughout this process, we were also testing the strings for power potential, creep, string-on-string friction, and linearity.
Linearity is a significant property of string; however, it does not get the attention we believe it deserves. So, this little post will begin to change that. We will start with some images and explain what we see in them.
String Behavior
Four different string materials are represented here from left to right:
- RPM Blast
- IsoSpeed Polypropylene Composite
- Babolat VS Touch Natrual Gut
- Ashaway MonoGut ZX Polyether ether ketone (PEEK)
The entire chart is important, but the real property we are interested in for this post is “linearity”.
- Linearity is how straight the plot is from the beginning to failure.
- Failure is the vertical line associated with each string material.
A glance will show MonoGut ZX with the longest linear track, however, Babolat VS Touch is the very “straightest”, followed by IsoSpeed and RPM Blast.
OK, but why do we care? We care because when we say a string will play better longer, it is based on the linearity which is the property directly related to consistency.
Better predictability = better performance
Players perceive predictability more than raw stiffness.
A string that ages predictably plays better longer, even if it’s not the softest or most powerful.
That’s it!
Now all we need to do is quantify “better”.
I will leave that up to you.
Cross String Tension…Yikes!
Cross-string tensions, or actually reference tensions, are the topic of this brief post.
First, every tennis racquet has a “natural” ratio, that is, if the reference tension (and machine setting ) is 50 for both the main string and cross string when the racquet is removed from the stringing machine, the tensions remaining will be in the area of around 50 for the mains and 37 for the cross.
The resultant tension is the natural ratio of that specific racquet.
The issue with changing cross-string tension either higher or lower than the main is that the racquet has changed shape. That is why we test for In-Plane stiffness for every racquet. The higher the In-Plane stiffness, the higher the cross-string tension will remain upon removal from the machine.
If the racquet has very low In-Plane stiffness, it has expanded in width with only the main string installed, so the cross strings need to pull the racquet back into a better (hopefully original) shape.
So, when deciding how much variation you want between the main and cross strings, please consider the racquet! In most cases, we suggest using the same string tension setting for both the main and the cross, since the cross string tension will naturally be lower.
Our True Tension Professional stringing equipment supports the racquet in such a way that we install the main string and cross string at the natural ratio, so the racquet does not change shape and the string bed is consistent.
If you are curious about In-Plane stiffness for a specific tennis racquet, please leave a comment below.
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.
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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.
Questron Cycle Update
Every string that enters the World Headquarters of Racquet Quest goes through the Questron cycle. We have posted images of the product of the cycle, but not the entire process that the Questron goes through to create these posts.
The following video is the entire process from start to post. We look forward to your comments!
If you have a string, or strings, that you would like to know more about, please let us know. We may have already put them through the Questron Cycle.
I mistakenly said “Z” axis when I meant “X” axis, if you caught it.
Racquet Quest, LLC
