How can flexible racquets be powerful?

Discussion in 'Racquets' started by Ashley D, Feb 18, 2013.

  1. corners

    corners Legend

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    Yeah, it could totally be your perception. Two other things that could result in perceptual errors relating to stiff racquets are dwell time and shock, which are related. When the ball impacts a stiff racquet it will stay on the strings a shorter amount of time. The briefer this "dwell time" the greater the shock transmitted to the arm. In their books, Cross and Lindsey hypothesized that players associate brief dwell time and greater shock with fast shots: The ball is on the strings for a shorter time and the brain interprets this to mean that the ball rebounds with more speed as a result. But this is akin to concluding that because a train stopped only briefly at the station that it then left the station with greater acceleration. Also, the brain may interpret the "crisp" shock of a stiff racquet as indicative of a fast shot. The impact felt violent and forceful, so the resulting shot must have been very fast, right? But as the data shows, the actual difference in shot speed is very small. The difference in shock might be great but the difference in shot speed is not, at least that's what the data says. I think it's likely that our nervous systems are better at gauging shock at the hand, wrist and elbow than they are at accurately judging shot speed, particularly as it seems very difficult to isolate speed from a shot's angle, trajectory, spin and depth.

    On the other hand, the physics of racquets, strings and the players using them turns out to be surprisingly complex. It could be that further experiments will turn up some error and we'll then hear that stiffness is more important than the current experimental results show. But without some new experiment, we're left with what we have now: the results of various experiments showing that stiffness doesn't make that big a difference in power, and the generally held perception by players that it does. I tend to trust data acquired in controlled experiments over my own perception because I know what a knucklehead I am, but I also don't think subjective perceptions should be ignored.
     
    Last edited: Feb 23, 2013
  2. corners

    corners Legend

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    And he beat both Nadal and Djokovic, in their primes, even with a partially dead arm :)
     
  3. mikeler

    mikeler G.O.A.T.

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    ^^^ Can you expand on your reply to me? I kid, I kid.
     
  4. marosmith

    marosmith Professional

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    I agree with this in that rackets flex in different places, different composition of materials also contributes to feel etc so the RDC rating does not tell the entire story.

    I think the point is the research shows that the concept that "stiff rackets are significantly more powerful and spin friendly and more suited to he modern game" is a fallacy.

    I think a larger point can be made that targeting older players, and beginners, weekend warriors etc with super stiff rackets does not improve their game. All it really does is lead to a number of upper extremity injuries based on the lie that they must use those types of frames.
     
    Last edited: Feb 23, 2013
  5. anubis

    anubis Hall of Fame

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    I read "The Inch That Changed Tennis Forever", it's a great read.

    So if my APD turns out to give me more trouble than it's worth, would you suggest a Donna Pro One as something similar, but with less stiffness?
     
  6. ChicagoJack

    ChicagoJack Hall of Fame

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    hi anubis,

    1. When you've got pain in the forearm and especially the wrist, choosing an appropriate racquet is literally, a balancing act. If you go too low in swingweight and mass, the ball is just going to beat up on the racquet upon impact, and you'll feel that impact shock and vibration. Racquets with more mass feel more comfortable when you miss the sweet spot, said another way, the additional mass creates a larger sweet spot.

    2. However, if your sw is too high, that's not good either, that's when you begin to "muscle" and "arm" the ball. You don't want a racquet where you are struggling to control the head, because that's when you begin to squeeze the grip too tightly, and begin to overly engage all those pesky little tie in muscles around the elbow, forearm and wrist that are screaming for a little rest. You also do not want an even balanced or HH racquet in your case. A balance of -4 to -12 points would be much better. The effect of tail weighting to impact shock, vibration, dwell time, and manuverability is a really deep topic, but suffice to say it's something that might really work for you.

    3. It's really hard for me to evaluate from here, what's the correct sw window for you. That's something you'll have to experiment with. But just judging from your comments, it seems you are more comfortable with the lower sw of the APD at 318, and the open pattern suits your stroke a bit better as well. You like the on court results with that combo, it's just that the ADP is causing you some wrist pain. One solution is to shop for something in that SW window that's open pattern, and a bit more comfy. The Pro One hits like buttah, but the sw is 327. I'm thinking that's a bit high for your current situation. The first thing that came to mind when you asked was the Donnay X-P Dual Black 102. That's a really sweet hit, and has room for adding some mass with the customization kit as your injury heals. It's an easy swing for intermediates, but with the right tuning can be used effectively at the higher levels as well. You could grow into that one, it's also the same frame Courier has been using on the Power Shares tour as of late. I've a personal bias towards Donnay, Volkl and HEAD frames, but when I screen for SW under 325, open pattern, lowish flex, there's lots of really good options. I've posted just a few for you below.

    [​IMG]

    [​IMG]

    [​IMG]

    -Jack
     
    Last edited: Feb 24, 2013
  7. Power Player

    Power Player G.O.A.T.

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    Here is one thing science cant really show, but its why stiff racquets can make tennis easier for people. (i dont like stiff racquets btw).

    Defensive shots for lower level players are easier to send back deep. Does that mean the racquet has more power? Honestly i do not know, but if you go grab a stock apd its just easier to get balls back by arming it compared to a flexier racquet. I think all of this is bad, but i believe it is why companies continue to make mostly stiff racquets nowadays.

    Once you get your footwork down and can hit defensive shots with balance, all this goes out the window. But my main point is that tennis is such a dynamic game that it is very hard to scientifically measure how a racquet performs for every type of shot. Which is why demoing is so important to really figuring out what works for you.
     
  8. Ashley D

    Ashley D Rookie

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    I think we now know, based on Chicago Jack and Corners posts, that it has nothing to do with the flex. It must be other qualities of the APD that make it easier to get the ball back. Unless the player is hitting the ball right at the tip or the base of the stringbed, as has been talked about.
     
  9. Power Player

    Power Player G.O.A.T.

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    I think you missed my point.

    There really is no way to scientifically measure how a racquet responds to every type of shot yet. What other qualities would there be? It has to have something to do with the stiffness on those types of shots.

    I personally think the combo of SW and stiffness is what does it.
     
    Last edited: Feb 24, 2013
  10. Ashley D

    Ashley D Rookie

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    Sorry if I missed your point. I think the other qualities are beam width, swingweight, length, etc. If you believe Corners and Chicago Jack, then stiffness has the least to do with it and swingweight the most. Not trying to argue with you, by any means. Just trying to get my head around it too!
     
  11. anubis

    anubis Hall of Fame

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    Thanks again Jack for some great advice. I'll keep these in mind if the pain becomes too much for me. Right now it hasn't yet, but then again I'm not playing as much as i will be in the spring. I'm captaining a men's 3.0 team and am one of the few singles players on it, so I'll be playing a lot of matches, along with ladders and practice. Nothing exacerbates potential pain like putting in lots of hours on the court!

    I really hope the APD works out for me and I can manage the pain through rest and tension management. I just played five doubles matches in the last three days and won all five. I've actually played 8 doubles matches so far with this racquet and won all 8 -- which never happens with me.

    I've been hitting lots of winners per match, and a few aces -- all things that I never got with my Radical. I can't ignore the fact that in any given doubles match I play, I hit on average 5 to 6 winners per set. With my Radical, I never hit any winners per set. For me, results count and if I had to give up the APD, I'll likely go back to losing matches.

    But with the APD, I'm struggling with singles matches. Played two singles matches with people of like skill and I got bageled both times. So I need to do some tweaking in that regard.

    Thanks again!
     
  12. TimothyO

    TimothyO Hall of Fame

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    This is an excellent point and one reason I believe that light, stiff, HH frames often sold to new players can inhibit development and cause arm issues. They allow one to still return a ball with bad form. It's not pretty, it's not accurate, it won't work against really heavy shots, but for most low and mid level rec play you can flick your wrist and return a floater with another floater.

    Your wrist and elbow will hurt eventually but at leas you're playing "tennis".

    Meanwhile heavier, higher SW frames, while still powerful, are harder to snap around using the wrist. You need to take a full swing to access that power. And during that swing you need to be more confident and accurate since you can't use your wrist and elbow to cheat that heavy mass into contact at the last moment like you can with a heavier frame.

    I've come to the conclusion that a lot of "modern" frames cause injury because they enable one to play tennis using poor, injury inducing technique. Sure, you return the ball, but at significant health cost.
     
  13. Muppet

    Muppet Hall of Fame

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    In response to the thread title:

    I think my flexier racquets increase dwell time just a bit, giving me the opportunity to transfer more of my momentum into the ball. While the 4 ms or so of dwell is not long enough for me to figure out and perform this momentum transfer, I believe my body has learned it from previous shots and can feed more power to the ball, with a flexible stick (Dunlop 200 series.)
     
  14. LeeD

    LeeD Bionic Poster

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    Of course, you know it, I know it, but most people here want to isolate the body from the racket.
    We know it's linked together, one is nothing without the other.
     
  15. Ashley D

    Ashley D Rookie

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    Well that's a load of tripe. We know we CAN isolate one from the other. What you're disputing is whether it tells us anything. I, for one, think it's worth studying the inherent difference between properties of a racquet. Which, incedently, you can ONLY do by removing individual variance between people. What your disputing is if this is a worthwhile activity.
     
  16. Power Player

    Power Player G.O.A.T.

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    I agree that the SW is key for sure and the #1 thing. I just think it is impossible (yet) to prove completely that on defensive shots you don't get more power with a stiffer racquet. The only reason I disagree is simply real world experience and the fact that these types of intangibles can not be measured yet.

    I just find stiffer racquets to be a little more powerful on these types of shots.

    Basically the main thing is SW. I completely agree. But flexible racquets feel so much better (subjective opinion - mine) and are a lot better for the arm, so you have to wonder why companies keep cranking up the stiffness. I believe it is to make tennis easier. Just my guess.

    Definitely not arguing anyone either. I think everyone is still figuring it out, and so many people hit the ball so differently, that it is very hard to nail down a universal answer.
     
  17. Ashley D

    Ashley D Rookie

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    Yeah fair points. I prefer flexi racquets too, for the reasons you mentioned.
     
  18. Relinquis

    Relinquis Hall of Fame

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    when you're out of position, or are a beginner (i.e. usually out of position) the lighter*, stiffer racquet will allow you to make contact more easily with the ball. you might even get to it in front of your body and be able to hit through it generating more power than if you just tapped it while outstretched, limbs flailing, with the ball behind your body... or if you missed the ball entirely.

    Still, i prefer the heavier, flexible sticks. removes shortcuts and allows you to focus on the proper technique and movement. also, when picking up a lighter stick afterwards you will still benefit from the good form developed with the heavier stick and just swing faster. at least that's what i feel when moving between my sticks.

    * Stiffer sticks are usually light, static weight if not swingwieght as well.
     
    Last edited: Feb 24, 2013
  19. LeeD

    LeeD Bionic Poster

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    Racket characteristics without adding a player are useless. The player is always IN the equation.
    If you so dumb as to isolate it, then why not always bring the most firepower to every fight? Think, for a change. To fight in a closet, why not bring an atomic bomb?
    Or, would a knife be better?
    You cannot possibly be so uninformed that you don't know the playing characteristics of stiff vs soft rackets.
    Assuming you play tennis, of course.
     
  20. MikeHitsHard93

    MikeHitsHard93 Hall of Fame

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    Arguing for the sake of arguing?...
     
  21. LeeD

    LeeD Bionic Poster

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    Read post 165.
    Is this not supposed to be an exchange of ideas?
    His view are valid, so are mine, and they are different.
     
  22. Ashley D

    Ashley D Rookie

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    These are two of the worst analogies I've ever heard. You're insisting on grounding the discusion in 'reality' rather than 'science', yet your best examples are the above and the fictional movie Predator!
     
    Last edited: Feb 24, 2013
  23. Overdrive

    Overdrive Legend

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    Umm... Am I missing something here? :confused:
     
  24. LeeD

    LeeD Bionic Poster

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    Just a friendly exchange of ideas.
    One person says you can evauate the racket's characteristics irrespective of the player who wields the racket.
    The other person says you HAVE to tie in the person using the racket to evauate the performance of the combined unit. That person says a racket performs differently for different people.
    While I would like to know how a propective tire might work based on tests and scientific analysis, I'd better know from someone's experience if that tire actually works for MY car.
     
  25. Ashley D

    Ashley D Rookie

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    Fine, I'll play your game, but you've dragged this thread into ridiculousness. Surely you can use the scientific analysis of the tire to at least narrow down the search for the tire that MIGHT work for your car. You CAN measure the qualities of the tire without the car. That's just a fact. What you're arguing about is the usefulness of doing this.
     
    Last edited: Feb 24, 2013
  26. jimbo333

    jimbo333 Hall of Fame

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    I think your last point above is really important point. The stiffer/lighter rackets can be swung faster, I think therefore giving the impression that stiffer is significantly more powerful than flexible rackets, whereas in reality this is definitely not the case.

    I will sum up my views on this superb thread tomorrow!
     
  27. jimbo333

    jimbo333 Hall of Fame

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    Right, well this is possibly the best thread I've seen here for technical info, just superb, special thanks to ChicagoJack and Corners:)
    What I've learnt, and my conclusions:-

    1. By far the most important factors for power are swing speed and racket swingweight. If you hit the ball in the middle of the stringbed, a stiff racket over a flexible one is almost the same in terms of power (all other factors being equal).

    2. Most stiff rackets are light, and therefore I think feel more powerful to many people, when in reality they are not, because they can be swung faster than most flexible rackets which tend to be heavier (a generalisation I know, but true I think). I think if you did a blind test with light/stiff and light/flexible rackets, with everything else being the same, telling them one is stiff and one flexible, the person could not tell which racket is more powerful. They would in fact be about the same in power (all other factors being equal), which would confuse many people, including me until I read this thread.

    3. I think the reason we keep the ball in play better with a flexible racket (which lots of people say), rather than a stiff one, is because the flexible racket creates more "dwell time" of ball on racket/strings, creating more spin, and thus keeping the ball in court. Lots of people think a stiff racket is more powerful, but in reality flexible rackets are about the same in terms of power (all other factors being equal).

    I realise there are always exceptions, but I would be interested in others views on these points please?
     
    Last edited: Feb 28, 2013
  28. sureshs

    sureshs Bionic Poster

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    Head size also makes a huge difference in power
     
  29. sureshs

    sureshs Bionic Poster

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    Stiffness is a great indicator of feel. A Dunlop with RA of 60 or a Prince Rebel with 59 or so feel totally different from a Wilson 65 or Bab 70.
     
  30. LeeD

    LeeD Bionic Poster

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    The PLAYER makes it powerful.
     
  31. jimbo333

    jimbo333 Hall of Fame

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    Yes the player does indeed, but I've learnt that flexible rackets are basically as powerful as stiff rackets in general (all other factors being equal), which I didn't know before this thread.
     
  32. LeeD

    LeeD Bionic Poster

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    and a weak hitting player hits weakly whether using a PureDrive + or a POG/Microgel.
     
  33. jimbo333

    jimbo333 Hall of Fame

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    It does make a difference, but I got logged out when editing my thread (annoying), and I was saying "all other factors being equal" like headsize for example being a factor.
     
  34. sureshs

    sureshs Bionic Poster

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    They are not. All other factors being equal, stiff rackets have more power as they return more energy to the ball. Flexible rackets have more of a trampoline effect, but that is offset by the energy absorption, making stiffer rackets more powerful overall.
     
  35. LeeD

    LeeD Bionic Poster

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    +1 here, I agree with someone who has even more posts than I do.....
    That's why more stiff racket's are sold nowadaze.
     
  36. jimbo333

    jimbo333 Hall of Fame

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    No, the difference is negligible. Have you read the whole thread? See post111 below from Corners.

    I don't know of any published research that contradicts the view he presented. Bottom line: "power", and the role stiffness plays in power, has been grossly oversold by racquet manufacturers. I've posted this before, but in a paper published last year and financed by Prince, an analysis using a finite element computer model found that if you had two racquets, identical in all respects except that one was twice as stiff, say 65 RDC vs. 130 RDC, the stiffer frame would give you about 5 extra miles per hour on a hard groundstroke. But the frames on the market today differ by only 10-15 RDC points, not 65! The difference in power between a flexy (60 RDC) frame and stiff one (70 RDC) is really not that great.
     
    Last edited: Feb 28, 2013
  37. jimbo333

    jimbo333 Hall of Fame

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    See above......
     
  38. LeeD

    LeeD Bionic Poster

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    I think you only have to hit with a PD, then hit with IG, and you'd feel the difference.
    But if you insist on scientific tennis, so be it.
     
  39. jimbo333

    jimbo333 Hall of Fame

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    They do feel different, but that is not the point. If you swing each with same speed etc they will generate about the same power, even though one is quite a bit stiffer than the other!
     
  40. sureshs

    sureshs Bionic Poster

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    Two things:

    1. Notice the numbers on the edges of the sweetzone. The PD is higher. It makes a significant difference in many practical situations.

    2. These numbers are determined by firing balls head on to a stationary frame. I am not sure they are completely valid when the frame is also moving.

    3. The difference in stiffness may be be more pronounced in the 55 to 65 range, and tapering off above 65.
     
  41. LeeD

    LeeD Bionic Poster

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    If you swing the PD and the IG at the same speed, you'd get tennis elbow with the PD and hit a good ball with the IG.
    Substitute MicroGel for IG, and you'd notice the difference in the speed of the ball leaving your racket. Add MORE swingspeed, and it becomes equal again.
     
  42. jimbo333

    jimbo333 Hall of Fame

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    Two things?

    I think I can see where you are going wrong scientifically:)

    From what I understand you are probably wrong, i think you need to provide some evidence.
     
  43. sureshs

    sureshs Bionic Poster

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    Oh I edited my post within the time period so it did not show as an edit
     
  44. MikeHitsHard93

    MikeHitsHard93 Hall of Fame

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    Here's one for you...if heavy, flexible rackets like the prostaff 6.0 have more power than light, stiff rackets like a pure drive, than why shouldn't heavy hitters just use these so called "less powerful" rackets rather than the heavy flexible ones? The stiff ones have less power and hard hitters don't need more power...
     
  45. sureshs

    sureshs Bionic Poster

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    The evidence is right in your numbers. The PD is more powerful in most cases.
     
  46. jimbo333

    jimbo333 Hall of Fame

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    Well I personally wouldn't use the PD. I currently use a Angell custom 95 18x20 RA63, the best modern racket I've ever used!

    Flexible, yet powerful, and accurate, a really brilliant tennis racket, I really recommend everyone tries one at least.
     
  47. LeeD

    LeeD Bionic Poster

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    I think what is WRONG is someone trying to figure racket power on paper, while ignoring the simple idea of HITTING WITH THE RACKETS!
    And isolating the racket from the player, of course.
     
  48. sureshs

    sureshs Bionic Poster

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    I remember a thread in which drakulie proved that the K90 was more powerful than a Bab. It is true. It is due to weight.

    I have posted this many times, but there are 2 types of power. Intrinsic power comes from weight and dominates at low swing speeds. Extrinsic power comes from stiffness and head size and dominates at high swing speeds.

    There is another issue: power as measured by the recoil tests essentially measures the recoil coefficient of a stationary frame. It is not the same as the plow through of a high SW frame. They are related, and interact with each other, but they are not the same.
     
  49. jimbo333

    jimbo333 Hall of Fame

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    The difference in power really is negligible though looking at those figures. As for your point about 55RA, that might make more difference, but how many rackets have RA of 55 these days?
     
  50. LeeD

    LeeD Bionic Poster

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    Becker's and Microgels come in mind.
    And figures don't compute when placed in the real world. The reason? Because the player becomes involved.
     

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