Precision tension: load cells and racquet stringing
The Wimbledon Championships 2026 start this week, with fans glued to matches that see the world’s best players competing at the only tennis major held on outdoor grass courts. Every elite player will have their own support team to look after their health, welfare, match strategies, and of course their tennis racquets, strung to specific tensions using stringing machines with load cells.
Taking the tension
The tension of a tennis racquet’s strings can significantly affect a player’s performance during a pro tour. Professional players will therefore adjust their racquet’s string tension throughout the season and between tournaments to optimise string tensions for different playing surfaces (grass, clay), conditions (high humidity, rain, etc), and their own fitness levels.
Load cells have been used for decades in stringing machines to measure, calibrate, and record the exact tension applied to the strings and the racquet frames. Portable versions enable players, coaches and support teams to rapidly and reliably check and change tensions as required.
What are the standard range of tensions for tennis strings?
According to the Lawn Tennis Association, different string tensions can affect the shot and the overall performance considerably: (1) .
• Low tension strings (40-50 lbs)
Shots have more power and depth, with better spin potential, and reduced arm strain. However, players have less control of fast shots and strings have more movement.
• Medium tension strings (50-60 lbs)
A good balance of control and power, allowing for comfortable playing in long matches.
• High tension (60+lbs)
Better control and precision for players who generate their own power. Offering less string movement but also less comfort, and an increased risk of arm injuries.
The ideal string tension
The Tennisnerd YouTube channel (4) looked at the string tensions for those competing at the Houston ATP 2026. From the stats, it’s clear many pros have their strings at either the top end of Low or the lower range of Medium as per the Lawn Tennis guide. This might not be as expected, given the lower rates of precision, but over long matches, the lower tension will reduce the risk of arm strain or injury.
A team of researchers investigating “Effects of different tennis racket string tension on forehand stroke effect and racket dynamic impact” (8) concluded that:
“A medium string tension within the racket permissible range is beneficial not only for improving stroke effect but also for minimizing the risk of arm injuries due to vibrations and impact forces during play. For racket manufacturers, it is recommended to optimize the racket’s trampoline effect to absorb the impact load during the stroke, which can reduce the incidence of forearm injuries and the development of tennis elbow.”
Different string materials and string machine calibration
Tennis strings types and materials include:
- Natural gut
- Polyester
- Synthetic materials
- Hybrid blends of natural gut and synthetic materials
Increasingly, amateur players are choosing multifilament synthetic strings as a that mimic natural gut’s ‘arm-friendly’ elasticity but with a cheaper price tag.
With so many string types to deal with and the physical forces required to string modern racquets, major manufacturers of stringing machines recommend that the hard-working load cells inside are recalibrated every 25 uses. Click here for more details of our calibration service for all types of load cells, or browse replacement load cells at our online shop.
Stringing and racket frame distortion
One of the issues around high tension stringing is the ability of the tennis racket frame to withstand the tension required without distortion. According to research by a team from the University of Sydney:
“In order to measure the tension in one of the cross strings while stringing a racket, a load cell was mounted in a metal frame attached externally to the racket at the 3 o’clock position … The results highlight the fact that a significant loss in tension can arise from friction and from distortion of the frame, even when the frame is securely clamped. (6)
The ‘feel’ of a tennis shot
In an interesting experiment at the self-styled Tennis Warehouse University, a team investigated how string tension can affect the ‘feel’ of a shot. The issue is that:
“”Feel” is a subjective interpretation derived from measurable (and perceptible) events such as force, shock, vibration, deformation, contact time, sound, and stiffness. These interpretations then may influence players’ perceptions of what they think the ball speed is. Those interpretations are often then connected to the racquet or string as a “property” such as “soft,” “powerful,” “harsh,” “solid,” “tinny,” etc. “ (3)
After testing ball impact on strings, the team concluded that:
“The coefficient of restitution (COR, or e) measures how much of that energy is returned … there is not much variation in COR between materials or tensions. There is a bit of variation at tensions below 35 lb, but few players string their racquets at those tensions. There may be a “feel” difference however.” (4)
Tennis and load cells FAQs
In 2025, the price has risen to £2.95 a portion, which includes 10 Grade 1 British strawberries and cream (or vegan equivalent). During the two weeks of the Grand Slam tournament, spectators will consume around 28,000kg of strawberries and 7000ltrs of cream. (7)
Yes we do – this one: Getting a grip.
Sports equipment manufacturers Head offer a step by step guide here (6), or watch the Yonex stringing team video: https://youtu.be/2E9aD2XoPBw?si=7NesMYVkMSGAkR7Z (8)
Natural gut strings are made from animal intestines, usually cow. They are highly elastic, stretching and returning to its natural form more rapidly than synthetic materials. According to Tennis Warehouse:
“Natural gut holds it tension and playability … You don’t need to restring very often because it will play well throughout its life.”
Load cell calibration by Richmond Industries
We offer full system calibration at our manufacturing base in Reading UK for most types of load cells. We can calibrate most load cells and indicators from a few grams to 1000 Tonne, with or without digital displays, plus load cell amplifiers, and load cell USB accessories. All our calibrations are traceable to national standards.
For more details:
About the author
Chris Beasley is Director of Richmond Industries Ltd, designers and manufacturers of advanced load cells and force transducers for industry, governments and universities all over the world.
REFERENCES:
(1) Lawn Tennis Association. (n.d.). The ultimate guide to tennis strings. Retrieved February 15, 2026, from https://www.lta.org.uk/play/tennis-equipment-guide/the-ultimate-guide-to-tennis-strings/
(2) Tennis Warehouse. (n.d.). Some pros and cons of natural gut tennis string. Retrieved February 15, 2026, from https://www.tennis-warehouse.com/learningcenter/gearguides/tennisstring/someprosandconsofnaturalguttennisstring.html
(3) Tennis Warehouse University. (n.d.). Stringbeds. Retrieved February 15, 2026, from https://twu.tennis-warehouse.com/learningcenter/stringbeds.php
(4) How to choose tennis strings Video. (n.d.). YouTube. https://www.youtube.com/watch?v=mlH745vSdGc
(5) Cross, R., & Bower, R. (n.d.). Measurements of string tension in a tennis racket. University of Sydney & University of Technology Sydney. https://www.physics.usyd.edu.au
(6) HEAD. (n.d.). How to string a tennis racquet. Retrieved February 15, 2026, from https://www.head.com/enHR/rs/stories/how-to-string-a-tennis-racquet
(7) BBC Bitesize. (n.d.). Forces and pressure (or the specific page title). Retrieved February 15, 2026, from https://www.bbc.co.uk/bitesize/articles/zdvt8p3#znjcp9q
(8) How to string a tennis racket Video. (n.d.). YouTube. https://youtu.be/2E9aD2XoPBw
(9) Zhao, G., Li, C., & Liu, Y. (2025). Effects of different tennis racket string tension on forehand stroke effect and racket dynamic impact. PLOS ONE, 20(1), e0317442. https://doi.org/10.1371/journal.pone.0317442
