Question about stiffness vs RA ratings vs "flex"

[pman76]

Hi everyone,

I'm genuinely confused at this information presented.

I use this racket

https://www.*************.com/info/wilson-pro-staff-six-one-95-blx-racquet-review

and it has a "flex" rating of 63 and have tried out so many rackets, since my grommets are worn out, and am actively looking for replacements.

I bought this unfortunately without trying it out.

Wilson Pro Staff 97 Black Racquet

www.tennis-warehouse.com

This has an RA rating of 66. This racket, even though had a higher RA rating, flexes significantly more. With my Pro Staff 95 BLX racket, I feel absolutely no flex when I swing fast, but with so many rackets I've tried, I feel the flex. I feel the flex with the Pro staff 97, blade 98(this has an RA rating of 62) etc.

Could anyone help me out in understanding why I would feel the racket flexing on a supposedly more stiff racket? Would the counterveil versions be better?

Wilson Blade 98 16x19 Countervail Racquet

www.tennis-warehouse.com

stiffness rating of 66 - this would be the same as the Pro staff 97 though, but comparing this to the 100L,

Wilson Blade 100L v7 Racquet | Tennis Warehouse

www.tennis-warehouse.com

with a stiffness rating of 69, I feel absolutely no flex.

To guage how I would swing, I'm a mid level 4.5, with an aggressive attacking game(mostly baseline but some net play), with a 1hbh. If there are suggestions as to what I could try, with a similar feel to the Pro staff 95 BLX, I would greatly appreciate it.

Thanks all.

 

[snoflewis]

RA only measures flex at one point in the racket. It really depends on how/where the racket flexes. Also, flex is not the same as feel.

 

[Shangri La]

I dont buy the theory RA only measures flex at one point. It's like saying when you step on a scale you're only weighing your feet not the whole body.

 

[smalahove]

I dont buy the theory RA only measures flex at one point. It's like saying when you step on a scale you're only weighing your feet not the whole body.

Then you don't understand how you measure RA, esp. based on the scale weighing analogy.
When you use an RDC machine (or the Prince equivalent), "[it] calculate stiffness by applying force on the hoop of the frame while it's locked in at the handle and resting on a bar near the throat area which acts as a lever."*

This gives you two facts:

1) It's a static measure of stiffness
2) it only gives you a static stiffness measure of one plane/angle**

So, just as with the twist weight metric, it is of course possible to turn the racket incrementally to get more measurements, and not just the one plane.

3) it won't tell you how uniform the stiffness is throughout the frame, which as we know is often perceived as important by the players (stiff upper hoop, f.inst.)

In addition, many argue dynamic stiffness is a better metric for assessing how you perceive stiffness during play.
Measuring vibration frequency is a good metric for dynamic stiffness (measured in HZ). ***


* https://www.perfect-tennis.com/tennis-racquet-stiffness/#How_is_Tennis_Racquet_Stiffness_Measured
** The Clash line f.inst. has been developed to be significantly less stiff in the stringbed plane
*** http://twu.tennis-warehouse.com/cgi-bin/vibfrequency.cgi

 

[pman76]

Thanks. I am referring to the flex alone. The racket doesn't flex unless I swing hard(put away shot). That changes the dynamic of the racket for me, and I don't like it. I could perhaps get used to it?

 

[pman76]

Then you don't understand how you measure RA, esp. based on the scale weighing analogy.
When you use an RDC machine (or the Prince equivalent), "[it] calculate stiffness by applying force on the hoop of the frame while it's locked in at the handle and resting on a bar near the throat area which acts as a lever."*

This gives you two facts:

1) It's a static measure of stiffness
2) it only gives you a static stiffness measure of one plane/angle**

So, just as with the twist weight metric, it is of course possible to turn the racket incrementally to get more measurements, and not just the one plane.

3) it won't tell you how uniform the stiffness is throughout the frame, which as we know is often perceived as important by the players (stiff upper hoop, f.inst.)

In addition, many argue dynamic stiffness is a better metric for assessing how you perceive stiffness during play.
Measuring vibration frequency is a good metric for dynamic stiffness (measured in HZ). ***


* https://www.perfect-tennis.com/tennis-racquet-stiffness/#How_is_Tennis_Racquet_Stiffness_Measured
** The Clash line f.inst. has been developed to be significantly less stiff in the stringbed plane
*** http://twu.tennis-warehouse.com/cgi-bin/vibfrequency.cgi

Thanks for the detailed explanation here. Very informative.

So how would you characterize what I am describing? I feel the flex when i hit the ball hard(e.g. put away shot, or aggressive winner), and I don't like that. Is that stiffness? firmness? solidity through the swing process?

There has to be a way to define the differences without referring to an arbitrary flex number, since the more flexible racket is more rigid? This is where I am confused as to what I should be looking for.

 

[esm]

Thinking out loud - could it be the string/tension setup that may have caused this issue for you?

 

[snoflewis]

I dont buy the theory RA only measures flex at one point. It's like saying when you step on a scale you're only weighing your feet not the whole body.

That's literally how it's measured. Using your scale analogy, it's similar to static and swing weight. Just because 10 rackets are all 12 oz doesnt mean they all swing the same. Depends on how it's distributed.

 

[RD 7]

Then you don't understand how you measure RA, esp. based on the scale weighing analogy.
When you use an RDC machine (or the Prince equivalent), "[it] calculate stiffness by applying force on the hoop of the frame while it's locked in at the handle and resting on a bar near the throat area which acts as a lever."*

This gives you two facts:

1) It's a static measure of stiffness
2) it only gives you a static stiffness measure of one plane/angle**

So, just as with the twist weight metric, it is of course possible to turn the racket incrementally to get more measurements, and not just the one plane.

3) it won't tell you how uniform the stiffness is throughout the frame, which as we know is often perceived as important by the players (stiff upper hoop, f.inst.)

In addition, many argue dynamic stiffness is a better metric for assessing how you perceive stiffness during play.
Measuring vibration frequency is a good metric for dynamic stiffness (measured in HZ). ***


* https://www.perfect-tennis.com/tennis-racquet-stiffness/#How_is_Tennis_Racquet_Stiffness_Measured
** The Clash line f.inst. has been developed to be significantly less stiff in the stringbed plane
*** http://twu.tennis-warehouse.com/cgi-bin/vibfrequency.cgi

Great explanation smalahove (and snoflewis).

Similarly, imagine comparing the maneuverability of two different racquets by referencing balance but not swingweight. There are challenges to looking at some specs in isolation. It’s sort of like describing impact-vibration by referencing only RA (which is taken from 1 point in the shaft) rather than considering say vibration frequency, which encompasses all points tip to handle. If two racquets have a 66RA but one is significantly more flexible at the tip and ears, than it’s arguable that vibration frequency does a better job capturing the difference. This is emphatically not to say that RA is useless, rather, it is only to suggest the potential limitations of considering specs in isolation.

 

[Shangri La]

Then you don't understand how you measure RA, esp. based on the scale weighing analogy.
When you use an RDC machine (or the Prince equivalent), "[it] calculate stiffness by applying force on the hoop of the frame while it's locked in at the handle and resting on a bar near the throat area which acts as a lever."*

This gives you two facts:

1) It's a static measure of stiffness
2) it only gives you a static stiffness measure of one plane/angle**

So, just as with the twist weight metric, it is of course possible to turn the racket incrementally to get more measurements, and not just the one plane.

3) it won't tell you how uniform the stiffness is throughout the frame, which as we know is often perceived as important by the players (stiff upper hoop, f.inst.)

In addition, many argue dynamic stiffness is a better metric for assessing how you perceive stiffness during play.
Measuring vibration frequency is a good metric for dynamic stiffness (measured in HZ). ***


* https://www.perfect-tennis.com/tennis-racquet-stiffness/#How_is_Tennis_Racquet_Stiffness_Measured
** The Clash line f.inst. has been developed to be significantly less stiff in the stringbed plane
*** http://twu.tennis-warehouse.com/cgi-bin/vibfrequency.cgi

If you measure the stiffness of two otherwise identical racquets, with the only difference being one racquet has a very flexy part. And that flexy part is not where RA is measured.

Will you get different RA readings from the 2 racquets? Of course. All flexy/stiffness of the racquet, whether being the measuring point or not, is reflected in the final reading.

As to where that flex point is and how it affects play/feel is a different subject. I'm just point out that just becuase the flex point is not hte 'measuring point', it doesnt mean that flex point will not contribute to overall RA reading.

Just like despite your other parts of the body is not directly touching the scale, being not "where the weight is measured", they will all be reflected in the weight reading.

 

[snoflewis]

@pman76 - Did you add any weight to your PS95? I've hit with all the rackets you mentioned except the blade 100L and the blx pro staff 95 had a cleaner feel but was pretty unstable in stock form due to low SW. the PS97 is noticeably stiffer/firmer. im going to take a shot here... given that you didnt like the PS97 or the blade 98 but liked the blade 100L and blx PS95 (assuming it's stock), i think what you're referring to as "flex" is actually plowthrough or dwell time. the two rackets you liked have really low swingweight so the racket isnt exactly plowing through the ball as they would with the blade and PS97 and the ball isnt sitting on the strings as long. if this is the case, the blade CV 16x19 also won't help since it has a higher SW and a more muted feel on top of that.

if my guess is correct, you might want to try low SW stick or other platform sticks like your PS95. wilson ultra tour, TF 315 LTD, dunlop cx200 tour, somethign along those lines.

 

[pman76]

Thinking out loud - could it be the string/tension setup that may have caused this issue for you?

Good though. It’s the same exact string and same tension as my blx(nxt at 53 lbs). I feel the racket flexing and it’s obvious to me. It’s in a ton of rackets, with the exception of the blade 100L which doesn’t flex.

Again it’s only on hard/fast shots. Its bizarre that it’s not consistent either. I makes out always hard to figure out. Sometimes it flexes. Will try to describe it a different way. These are made up numbers.

Up to 85% swing speed, no issues. At 86% and above, there is flex.


Sent from my iPhone using Tapatalk

 

[pman76]

@pman76 - Did you add any weight to your PS95? I've hit with all the rackets you mentioned except the blade 100L and the blx pro staff 95 had a cleaner feel but was pretty unstable in stock form due to low SW. the PS97 is noticeably stiffer/firmer. im going to take a shot here... given that you didnt like the PS97 or the blade 98 but liked the blade 100L and blx PS95 (assuming it's stock), i think what you're referring to as "flex" is actually plowthrough or dwell time. the two rackets you liked have really low swingweight so the racket isnt exactly plowing through the ball as they would with the blade and PS97 and the ball isnt sitting on the strings as long. if this is the case, the blade CV 16x19 also won't help since it has a higher SW and a more muted feel on top of that.

if my guess is correct, you might want to try low SW stick or other platform sticks like your PS95. wilson ultra tour, TF 315 LTD, dunlop cx200 tour, somethign along those lines.

This is very interesting and you may be right as I was nodding as I was reading your reply.

Everything is stock and have never added anything to any of my rackets.

Have you played with the blx 90? That didn’t flex either and that had a much higher swing weight. How would you consider that racket in terms of plow through compared to the ps97 and blade.

On another note, I get prob 15%-20% more power with the ps97 when compared to the ps95 blx.


Sent from my iPhone using Tapatalk

 

[snoflewis]

Have you played with the blx 90? That didn’t flex either and that had a much higher swing weight. How would you consider that racket in terms of plow through compared to the ps97 and blade.

i had a few 1st gen red/black blx90, but wasnt as big of a fan as the 6.1 95 16x18 of the same generation. this is a bit surprising, since it's beefier than the PS97 or the blade, but i'm wondering if it's due to the denser stringbed in the 16x19 midsize head. if you have access to demo rackets, i'd be interested to hear what you think about the wilson ultra tour.

On another note, I get prob 15%-20% more power with the ps97 when compared to the ps95 blx.

the could be due to a lot of things including swingweight, headsize, stiffness, etc. you mentioned it was the same string setup, but 53lbs on a 95 and 97 sq in racket won't feel the same, and in my experience, the ps97 was a bit unpredictable off the stringbed for me.

 

[pman76]

i had a few 1st gen red/black blx90, but wasnt as big of a fan as the 6.1 95 16x18 of the same generation. this is a bit surprising, since it's beefier than the PS97 or the blade, but i'm wondering if it's due to the denser stringbed in the 16x19 midsize head. if you have access to demo rackets, i'd be interested to hear what you think about the wilson ultra tour.



the could be due to a lot of things including swingweight, headsize, stiffness, etc. you mentioned it was the same string setup, but 53lbs on a 95 and 97 sq in racket won't feel the same, and in my experience, the ps97 was a bit unpredictable off the stringbed for me.

Yeah it is a ton more unpredictable. I’m decent enough where I know where my ball is supposed to go, and I’ll hit very similar strokes and the ball varies by 10 feet, randomly, where as with my regular BLX, varies by 2 feet, and this is hitting it on center.

Unfortunately my store doesn’t carry it, but it seems to be going new for 109. May just bite the bullet and buy one. Thanks for the suggestion.


Sent from my iPhone using Tapatalk

 

[Crocodile]

What you feel in terms of flex in a racquet can be attributable to the way the beam is designed, the quality of the carbon and the direction of the lay up of graphite. Many manufacturers are now incorporating technologies to make racquets felt smoother and softer,
Back in the 80’s many flexible frames had harsh vibrations, something we used to call feel and the stiff frames were boards. Nowadays the flexible frames vibrate softly,