Tennis Racquet Stiffness & Flex
Explanation, Video & Charts
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When purchasing or evaluating a new tennis racquet, one of the many specifications you’ll encounter is tennis racquet stiffness or flex.
At first, it may just appear to be another number in the list of specs provided by racquet retailers. However, it’s worth considering racquet stiffness and understanding how it impacts performance and comfort, especially if you deal with arm injuries like tennis elbow.
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Racquet Stiffness Defined
Measuring Racquet Stiffness
Stiffness & Performance
Stiffness & Comfort
Stiffness Comparison Chart
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Video Explanation of Racquet Stiffness
If you’re looking for a more concise explanation of tennis racquet stiffness, check out my video below – I still dive into all of the critical details, which this guide further supports.
For reference, here are timestamps to the different sections of the video if you’d like to jump to a specific section.
0:17 – What is Racquet Stiffness?
0:41 – How is Stiffness Measured?
1:18 – Example Racquets with High & Low Ratings
1:26 – Racquet Stiffness & Performance
1:56 – Racquet Stiffness & Comfort
2:11 – Stiffness Comparison Chart
2:33 – Demoing Tennis Racquets
2:57 – Additional Comfort Considerations
Here are links to the resources I reference in the video:
In the following sections, I go deep to explore the topic of stiffness and flex – I hope you enjoy it!
What is Tennis Racquet Stiffness?
Tennis racquet stiffness is a numeric value assigned to each racquet that measures how much a frame flexes during contact with a ball.
As a beginner, this measurement may seem arbitrary, but it can be a useful measurement that helps guide a player’s decision-making process during their search for a tennis racquet.
This metric becomes most useful as a point of comparison. For example, if you hit with two racquets, one that features a high stiffness rating of 72 and the other a rating of 60, you’ll begin to develop a sense for how these ratings impact the feel and performance of a racquet.
However, even if you’ve never had the opportunity to compare two separate racquets, you can still benefit from understanding the pros and cons of high and low ratings.
If you’re in the market for a new tennis racquet, I’d encourage you to use specs like stiffness as a guide to help narrow down a selection of racquets but to try a few before you make a decision.
Not only will you gain a better feel for how specs translate to playing tennis, but you’ll also be more likely to find a racquet you love.
How is Racquet Stiffness Measured?
As you might imagine, racquet stiffness is not easy to measure without the right equipment. As a result, companies have developed machinery to measure a variety of tennis racquet characteristics, including racquet stiffness.
Perhaps the most common machine for measuring racquet stiffness is the Babolat RDC (racquet diagnostic center), which measures racquet stiffness, weight, swingweight, and balance as well as stringbed deflection, to help players understand when it’s time to restring.
Racquet stiffness is measured by securing a racquet’s handle to the machine and applying pressure to the tip of the racquet head, which causes the frame to flex slightly. Through this process, the Babolat RDC or similar devices can calculate a racquet’s stiffness index or rating, otherwise referred to as a racquet analysis or RA.
The range or scale for stiffness for racquets will usually fall between 50 and 85, where the lower number indicates a more flexible racquet, and the higher number a stiffer racquet. However, the majority of modern racquets will usually fall somewhere between 60 and 75.
The Babolat RDC can take these measurements within a few minutes, and they are great for comparison purposes. However, these machines are not easy to come by, so the easiest way to get a wide variety of the specifications is to check your favorite online retailer, as they typically provide this measurement for comparison purposes.
For fun, you can get a sense of a racquet’s stiffness by placing it down on a flat surface and applying pressure to the racquet’s head. You might be surprised at how much it bends. Just be careful, if you press too hard, you can damage your racquet.
Are There Other Forms of Measurement?
Absolutely. It’s reasonable to assume most major racquet manufactures have mechanisms for measuring racquet stiffness.
For example, Wilson has a machine that measures what they refer to as the Stiffness Index (SI). However, the method is different than Baboat’s, so it’s natural the ratings or numbers used to represent a given racquet’s stiffness are different.
Since the measurement values are somewhat arbitrary, they’re only useful if you compare different ratings taken from the same machine. In this case, the Babolat RDC is the industry standard and used for the vast majority of measurements you’ll find online.
Racquet Stiffness and Performance
There are three primary areas where players will experience shifts in the performance of racquets with different stiffness ratings. The three most noteworthy include:
Let’s dive into each separately.
One of the most common misconceptions with tennis racquet stiffness is that a more flexible racquet – that is one that bends or flexes under pressure – will produce more power than a stiff racquet that doesn’t bend as easily.
The assumption is that as a frame flexes and rebounds during a swing, additional energy passes to the ball. In theory, this seems logical. However, a tennis ball will stay on the stringbed for a fraction of a second, which is less time than it takes for the racquet to recover.
As a result, the more flexible a frame, the more energy it absorbs, which results in a loss in power when hitting. Consequently, a stiff tennis racquet will flex significantly less during a swing and deflect more energy or power.
For this same reason, control racquets, also known as player’s racquets, tend to have more flexible frames, resulting in less power potential for the racquet but greater overall control.
As you can imagine, this statement is relative. A beginner will not necessarily find an increase in control and accuracy by switching to a more flexible frame.
Instead, control is primarily a function of a player’s skill and technique, which, combined with a flexible lower-powered racquet, allows them to dictate the placement of the ball more accurately.
As an example, the control-centric Wilson Blade 98 (16×19) v8 has a stiffness index or rating of 61, compared with the high-powered Head Titanium Ti.S6, which sits at 75.
Closely related to control, feel, or sometimes referred to as touch, is another characteristic that many players associate with racquets of varying stiffness.
Players will often describe racquets with higher-end stiffness ratings as having a crisp or lively feel, which goes along with their higher power and lightweight construction.
On the other hand, flexible frames are often described as having a plush or stable feel. In many cases, this quality results from the heavier weight that racquets with low stiffness ratings tend to feature.
Regardless, a player will typically feel more connected with the ball when hitting and is particularly useful for types of shots that require more finesse, such as volleys or drop shots.
It’s worth noting that the type of strings you’re using, which is ultimately the surface that comes in contact with the ball, also have a dramatic impact on a racquet’s feel.
Racquet Stiffness and Comfort
Beyond power and control, racquet stiffness also has an impact on comfort. As a general rule, a stiffer tennis racquet will tend to pass more shock and lingering vibration to the player’s hand and arm, resulting in discomfort with prolonged use.
On the other hand, more flexible racquets will deflect energy upon impact, sending less shock and vibration to a player’s arm. However, it’s important to note that these are generalities.
In other words, a stiffer racquet won’t automatically be less comfortable than a more flexible frame. Other factors, such as the racquet’s weight and balance combined with strings, will contribute to a tennis racquet’s overall comfort, so it’s important to take stiffness in the context of the overall racquet design and specs.
Going back to the example above, the Head Titanium Ti.S6 is 2.5 ounces lighter than the Wilson Blade 98 (16×19) v8. For most beginners or players who don’t have a tremendous amount of strength, this would be a significantly more comfortable racquet to play with, even though it has a stiffness rating that is 5 points higher.
This point brings us to an important note about tennis racquet stiffness and comfort – it’s somewhat subjective. More specifically, every player will find varying degrees of comfort with the same racquet.
What’s more, two different racquets with nearly identical stiffness ratings can feel very different for the same player, so your opinion will come into play as you begin to trial racquets.
Thoughts on Tennis Elbow
If you’re suffering from tennis elbow or any discomfort in your arm, then your racquet’s stiffness is a worthy consideration.
As covered in the previous section, the stiffer the frame, the more shock, and vibration a player will feel. However, you’ll also want to consider these factors:
- Weight: heavier racquets absorb more shock
- Materials and construction: some materials and construction methods are better at absorbing shock than others; such is the case with Donnay racquet’s that feature solid-core frames to help absorb shock and vibration
- Balance: shock will decrease as a racquet’s balance point goes higher, i.e., head-heavy racquets
- Grip size: grips that are too small can cause the racquet to twist or move in your hand and lead to discomfort
Keep all of these factors in mind if you’re dealing with an arm injury.
Strings and Tension Considerations
As it relates to comfort and frame stiffness, strings and their tension can also play a role.
First, different types of strings will offer varying degrees of comfort. On the softer side, natural gut and multifilament will typically provide the highest level of comfort while polyester strings or kevlar will be harsher.
Similarly, tension can increase or decrease comfort with higher tensions increasing the stiffness of the stringbed and lower tensions offering up slightly more comfort.
When combined, a racquet with high stiffness rating, using less comfortable strings like polyester at higher tensions, can be a recipe for disaster, which you can take into consideration.
Racquet Stiffness Comparison Chart
Here’s a simple chart to help provide context for what to expect from racquets with various stiffness ratings generally.
Keep in mind that stiffness is one of a combination of attributes that produce a racquet’s feel. As a result, you’ll find racquets within each range that offer more or less power, control, or comfort.
Moreover, one player may find that a racquet with a higher stiffness rating plenty comfortable, while another may find the same racquet harsh and uncomfortable to play with for an extended period.
Let’s take a look at a few different racquets that fall at the high and low extremes of frame stiffness.
Stiffest Tennis Racquets
Here’s a selection of the five racquets with some of the highest stiffness ratings.
|Dunlop CS 10.0||76|
|Head Titanium Ti.S6||75|
|Volkl V-Feel 9||74|
|Wilson XP1 Racquet||73|
|Tecnifibre TFlash 300 CES||72|
Most Flexible Tennis Racquets
On the other end of the spectrum, here are a few racquets that feature ultra-low stiffness ratings.
|Wilson Triad XP5 Racquet||46|
|Prince Phantom Pro 100||54|
|Wilson Clash 100L||54|
|Head MicroGEL Radical OS||56|
|ProKennex Heritage C98 Redondo MP||57|
Frame stiffness is one of many criteria that can help players make an educated decision selecting a racquet. However, nothing beats getting out there and testing a racquet for yourself.
Once you find a racquet that fits your needs, take the time to demo the racquet. With each racquet you play with, you’ll gain more perspective, which you can use as a reference for future comparison.
If you’re on the hunt for a new tennis racquet, be sure to check our list of the 20+ best tennis racquets for 2022.
Do you still have questions? Feel free to post a comment below – we’d be happy to help!
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Hi guys interesting articles on tennis elbow ,I on the other hand suffered golfers elbow playing tennis which I now believe was caused through the purchase of a babolat pure drive. I then moved to the pro kennex q5 after 7 months off the court dropped string tension from57 to 54lbs NRG 2 17 gauge ,however I was thinking of the new volkl8 super g and am insure wether to focus on the lighter less stiff 300g or slightly heavier and slightly stiffer 315. My main reason for change is to go away from 16 x20 strings in my pro kennex to the volkl 16 x18 for a softer feel and greater spin, any advice would be greatly appreciated ,thanking you in anticipation Henri.
Know this is old, but if still curious, the general thinking is to utilize the heaviest racquet you can comfortably maneuver throughout a 3-Set match.
The reason is simple- higher racquet mass= more impact absorbed vs transferred to your arm……….
You want to play with HIGHEST MANAGEABLE STATIC WEIGHT/ STRUNG HL BALANCE 6pts +/ RA 67 OR LOWER/ rest is preference
It is also wise to ‘grow into’ a frame vs getting immediate impact if at rec / still improving level, or else you will constantly want to change bc Power becomes less and less desirable……..
Your current stick is actually very solid overall, and I’d give it some more time, as well as customizing to your preferred specs– almost EVERY racquet should be optimized to the player, with each new backup acquired matched to same specs for seamless transition from one frame to the next
Hope this helps
@clevelandStringer – thanks so much for your reply! I appreciate you taking the time to chime in with a great response.
@henri – looking at your question of “whether to focus on the lighter less stiff 300g or slightly heavier and slightly stiffer 315” I went ahead and pulled some quick stats for comparison which you can find below, but here are some high-level recommendations when looking for a racquet if you have tennis elbow:
For a more detailed analysis of these factors, check out our article on Selecting the Best Tennis Racquet for Tennis Elbow & Golfer’s Elbow.
Babolat Pure Drive
Head: 100sq in
Weight: 11.1 oz
Balance: 4pt HL
ProKennex Q5 (315 stats in parenthesis… wasn’t sure which you use)
Head: 100sq in (100sq in)
Weight: 11 oz (11.9 oz)
Balance: 4pts HL (8pts HL)
Stiffness: 66 (67)
Pattern: 16×20 (16×20)
Volkl Organix 8 (315 stats in parenthesis)
Head: 100sq in (100sq in)
Weight: 11 oz (11.6 oz)
Balance: 4pts HL (7pts HL)
Stiffness: 69 (70)
Pattern: 16×18 (16×18)
Back to your question, if you were to give the Volkl Organix 8 a shot, it would be worth starting with the 315. The stiffness rating is only 1pt higher than the 295, so you’d likely benefit from the extra weight, assuming it’s not too heavy for you.
Strictly looking at the stats for each racquet, your ProKennex is a great fit for your golfer’s elbow symptoms. Combined with your multifilament string NRG2, it should be a solid combo. My initial recommendation would be to stick with your ProKennex purely from an injury standpoint. However, unfortunately, for most players, it’s not only about the best racquet for their symptoms; it’s finding a balance between performance and easing their symptoms.
Hopefully, this gives you some extra food for thought. Let us know if you have any follow up questions.
All the best,
Hope not too late to respond and ask a question of Henri. I too am suffering from “golfer’s elbow” (medial side of elbow) as a result of tennis…in my case caused using I believe the Head TiS6 titanium racquet with a stiffness rating (RA) of 76. Brought the string tension to 55lbs and this was more comfortable but still not elbow friendly enough. Now playing with a Prince 110 EXO3 and this seems the best, except pace on my serves seems lower.
My real question is: Have you recovered from the golfer’s elbow yet and how long did it take? What procedures did you follow to aid in recovery? It’s been 6 months for me and still no relief and playing very little tennis.
If ANYONE, Henri or otherwise can help or suggest here, I would very much appreciate it. I have been to Orthopedics, did”re-hab” exercises etc, but it returns with a vengence when I return to playing. There is lots of information on the web about these conditions, but nothing really definitive. HELP!
Thanks for joining the conversation. I’m sorry to hear about your case of tennis elbow. “Returns with a vengeance” just about sums it all up.
Hopefully we can get a few people who have had bad cases of tennis elbow to chime in to talk more about their experience.
A few things I can recommend:
Wishing you the best of luck!
All the best,
I got hurt about one year ago. After I went to physiotherapist it turned out ok. Now I change to Prince esp 105l stiff 65 w280 Head Fl 17 gauge at 45lb and my arm is free from pain about 6 months. Last week I tried oversize 115 260 stiff 70 for 3 days it pained again. I go back to 105l again. To gain more power from this racket I add lead tape 20grm to the handle and chang string to Wilson shockshield 50lb. I do not know it ok or not. I am 58 years old need more power from racket without te. Thank for your suggestion… Pongchai from Trang Province Thailand…
Hi Ponchai! Thanks so much for visiting and sharing your challenge :)
For starters, you’re doing the right thing – experimenting with different racquets to get a first-hand feel for the difference. There is no better way to gauge the performance of a racquet. You’re dealing with a super common struggle for players in balancing the power that often comes with a stiffer racquet for the comfort of a lower-powered racquet with more control, so I’m glad you asked.
Out of the two options, I’d recommend the Prince 105 ESP, which it sounds like your already gravitating toward. The lower stiffness rating will provide you with more comfort as the frame flexes and absorbs impact on contact with the ball. Lead tape and some extra weight is a great way to help increase stability and further reduce vibration and shock. The handle is a great place to experiment, but I’d also recommend you test lead tape inside the upper portion of the racquet’s head.
Beyond that, I love that you’re also experimenting with your strings, and Wilson Shockshield is a worthy option for anyone struggling with arm pain. It’s a multifilament, and this category of strings is the best for anyone struggling with arm pain. Here are three others worth checking out:
– Tecnifibre X-One Biphase
– Wilson NXT
– Babolat Xcel
Since you mention a desire for power, Technifibre would be my top pick of those three for you. Best of luck with your arm, and please don’t hesitate to reach out with any other questions.
All the best,
What is the best racquet for better power, keeping a good control?
Babolat Aeropro Drive?
Wilson Juice 100?
Head Graphene MP Instinct?
Head Graphene MP Extreme?
Out of the four racquets you mentioned, I think the Babolat AeroPro Drive features the best blend between power and control.
All the best,
The article is really interesting. In my case I have an aero pro drive racquet and since I started using it tennis elbow and shoulder issues started too. I like the power of the babolat aero pro but the information avalable point a high incidence of arm issues with this racquet. I am considering to switch to the yonex ezone 98 ai with a stiffness of 62 vs the 71 for the babolat. Do you think is a good choice?
I’m sorry to hear that. Hopefully, changing racquets can resolve the issue for you. The Yonex EZONE 98 is a great racquet, which will have a softer, more muted feel. It’s certainly worth checking out and taking for a test drive.
If you haven’t yet, I’d also spend some time evaluating your strings as well. Multifilament are a great option to help increase your comfort level.
All the best,
Hi there I am looking at buying a new tennis racquet , after a long time away from playing ..(I used to play with an Emrik double edge when playing college comp.. But no longer have this racquet..
So as for my style of tennis I play: I serve mostly slice with the odd flat serve; I play right handed and have a topspin forehand and a single handed topspin b/hand but I mostly use a slice backhand. I used to enjoy coming to the net especially in doubles, but times have changed and I am happy to rally from the baseline.
I am looking at the Wilson Blade 98S and the Head Graphene XT Extreme MPA ..what do you think about these racquets, are they too stiff?? And would you recommend any other racquet given the information I have provided
\h and I am 40 yrs old , 5’7 and weigh70 kg with average size(not big but not small)and still quite fit..
Look forward to hearing from you
Thanks for stopping by and sharing. You’re the first person to mention Emrik racquet’s on TennisCompanion, which was fun to see in the comments.
As for the two racquets you’re looking at, my recommendation would be the Wilson Blade 98S. It’s a great racquet and features a lower stiffness rating, which it sounds like might be a concern of yours. Either way, both racquets are going to provide a dramatically different feel from your Emrik.
Since you’ve been away from the courts for a while, I’d recommend demoing a few racquets before jumping in to help establish a new baseline for yourself. From there, if the racquets you demo aren’t working out, you can narrow your selection by considering what you like and don’t like about the demos.
If you get to that point, I’d be happy to provide some feedback.
All the best,
say that you recommend from strings, for head extreme mp 300gr., I’m used to playing wilson blx juice pro 96 and solinco tur bit 1.25, but because of the weight, I decided to switch to 300gr
Before I start tossing out what might feel like random recommendations, I’d love to hear what strings you’ve used in the past and what you like and dislike about them.
Let me know, and I’ll be happy to share a few options. You might also want to check out this article as a starting point.
All the best,
Hi there. I have a 9 year old son and have recently purchased him a Babolat Pure Aero Junior 25 that is due to arrive soon. He is a keen player, has lessons for 3 hours a week, plays occasional matches and is making strides with hitting harder and with spin. He currently uses a Nadal aluminium racquet and has been advised by his coach to get a graphite one.
I note the issues people have had with tennis elbow and the Pure Drive. Is the stiffness less for the junior models? Provided he has good technique, if he’s not complaining of elbow pain now, do I have to worry that he may be more likely to develop elbow pain in the future compared to juniors using softer racquets? I don’t want him to develop a chronic injury too early in life!
Great question and awesome that you’re paying such close attention to how your son’s gear has the potential to impact his longevity on the court.
Although the ratings aren’t readily available, the aluminum racquet is less stiff, so it’s a reasonable concern. My recommendation would be to keep a close eye on it and check in with your son regularly. Everyone reacts differently to racquets, so it may not turn out to be an issue. Plus, at only 3 hours a week, it’s less likely to be an issue.
However, one of the areas many players get themselves into trouble is by using a stiffer racquet with a harsh string like polyester. At an early age, I’d recommend against it. However, a multifilament can be a great option in a stiffer racquet to help increase the comfort level.
Hopefully, that’s helpful.
All the best,