How can flexible racquets be powerful?

[jimbo333]

Originally Posted by Relinquis

Guys,

Stop Swearing... There are kids around and... You could get this thread deleted... and... You could get banned.

Learn to discuss and disagree without fighting. Be respectful please.

I was saying the same thing earlier in a very British polite way though. Didn't work for me

Anyway looks like they have gone now, or at least are no longer arguing.

Am still hoping ChicagoJack returns to answer my questions from post56 on page 3, he is probably very busy, I will try to be more patient.

[El Zed]

Originally Posted by onehandbh

I disagree. I think it's a hard racquet to use. Felt like a heavy
wet noodle to me.


Again, I totally disagree. The babolat pure drive and APD are
two of the easiest racquets to use if you string them with
full poly at a low tension. I've seen park hackers using bunting
strokes, wristy strokes, and all kinds of homemade methods
of hitting spin and the babolats helped them keep the
ball in with more spin, power, and a big sweet spot. Plus
stock they are light enough for most people.

I love the pure drive with full lux and a little lead, but
my wallet and elbow didn't like it -- otherwise I would
have switched to it. I initially tried it with synth gut and
it was completely uncontrollable. btw, no racquet
has ever given me pain. Only the pure drive.

I guess where I failed to make myself clear is the distinction between "being easy to use" and "being easy to use properly." Perhaps the correct phrasing would be that the APD is easy to use but more difficult to master (than the PT630).

Yes, lighter racquets inherently permit virtually everyone to pick up a racquet and to get some level of depth, pace, etc. This of course, just being a function of weight. I am not, however, speaking about this nor the tap-back game - I am talking about the use of the APD/PD in a competitive setting where one needs to hit with significant pace and/or spin. Contrary to the common perception, you can indeed take a full and strong cut with either the PD or APD - just as fast and hard as a Prestige or Radical. The common perception is that doing so will generally cause the ball to sail - which is true, very true. Once you learn to adjust, and then learn to adjust to maximize spin - this is rectified. That being said, you don't really have this issue with the PT630. With that racquet, you can hit a great traditional forehand or a nasty modern stroke presuming you have the strength to do so (especially over the match) - all without fearing that the ball will sail (overly so, at least).

[El Zed]

Originally Posted by jimbo333

I was saying the same thing earlier in a very British polite way though. Didn't work for me

Anyway looks like they have gone now, or at least are no longer arguing.

Am still hoping ChicagoJack returns to answer my questions from post56 on page 3, he is probably very busy, I will try to be more patient.

Ok, you too busy-bodies really need to stop. I'm sure if someone directly criticized you, you would speak up. So save it.

[kaiser]

Perhaps you should save it, Zed, you're spoiling an otherwise very enjoyable thread.

[El Zed]

Originally Posted by anubis

I am using BHB7, and I love it. I am not using blu tack, I have not yet experimented with weighting it at all. So far, I feel like the APD is perfectly weighted for me. I have issues with high swing weights, can't really whip that frame around fast enough.

As soon as I calibrate my new crank machine, I'm going to string it @ 48/46 lbs and see how it feels. I won't really know anything until it has about 8 hours on it though.

thanks for the help

Hi, Anubis -

Yeah, the BHB7 is a great string at a wonderful cost. I really wish I could help further, but I understand your preference for keeping the weight down. Unfortunately going through the Blu Tack/lead mod will get the racquet to at least 12 oz. if not more. It does transform the feel and makes it a very, very solid racquet, but it does inherently change it. Funny enough had the chance to use another original APD (the Nadal version) yesterday, and disliked the feel right from the get-go (especially in comparison to the modded GT).

[El Zed]

Originally Posted by kaiser

Perhaps you should save it, Zed, you're spoiling an otherwise very enjoyable thread.

Perhaps you should stay out of it, kaiser. No, you SHOULD stay out of it.

Again, sticking your nose where it doesn't belong?

[El Zed]

Originally Posted by jimbo333

I was saying the same thing earlier in a very British polite way though. Didn't work for me

Anyway looks like they have gone now, or at least are no longer arguing.

Am still hoping ChicagoJack returns to answer my questions from post56 on page 3, he is probably very busy, I will try to be more patient.

Or you could just order the same book that he derives most of his information from.... You know, supporting the person, who actually went about engaging in the research and authoring the work....

[marosmith]

So does anyone disagree with chicagojacks (even if it is recycled) information or conclusions? And if so can they provide research which would contradict it?

[Relinquis]

nope. chicagojack's posts seem legit.

i don't know what el zed is on about though. i can't see how a properly weighted up APD can magically provide more spin unless it was attributable to one of it's physical characteristics that relates to launch angle or spin, i.e. string pattern, or such.

i don't see how it's comparative stiffness is what allows it more spin or power compared to a more flexible stick (apart from an incremental amount of power at the tip, after adding weight to the stock babolat stick to get it's swing weight in line).

[ultradr]

My ideal stiffness of a frame seem to be around 65. It's generally stiff but
it still flexes on high impact.

[corners]

Originally Posted by marosmith

So does anyone disagree with chicagojacks (even if it is recycled) information or conclusions? And if so can they provide research which would contradict it?

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.

Consider this comparison. 2012 Babolat Pure Drive Roddick vs. 2012 Head Youtek IG Radical Pro. This is a really good comparison because the frames that TW University tested both had the same swingweights (328 ) and nearly identical twistweights.



The Pure Drive Roddick had stiffness of 72 and the IG Rad Pro 64. And yet they pretty much have the same power. The PDR has slightly greater power potential at the three locations 2 inches above the center, and just a little bit greater power to either side of center. But look what this actually means to a player in terms of shot speed:



An extra MPH 2 inches above center, a couple extra MPH if you want to hit right below the tip. You can see from the second graphic that hitting in the center of the strings is where you get your fastest shots. And that is exactly where stiff frames help you the least. Basically, stiff racquets give you a tiny power boost near the tip and toward 3&9. This effectively expands the "sweetzone", in so far as your shots will be slightly faster if you miss the center of the strings. A better way than "powerful" to describe this would be "forgiving".

It should be clear to anyone looking at the above graphs, and even more clear to anyone looking through the TWU Power Potential database, that the key to power is swingweight. But manufacturers won't try to sell you racquets based on swingweight because swingweight is a double edged sword. High swingweight means a racquet is inherently powerful, but it also means that it is harder to swing fast. So if you get a high-swingweight stick in your quest for power you might find your swingspeed to be slower and your shots to end up being the same speed as before. So, in terms of power, there is no free lunch. Well, there is natural gut, but you'll lose a couple lunches to pay for it.

[Ashley D]

I think the only one who refutes it is LeeD. Although I'm not sure why. Something to do with inherent problems with science and the movie Predator. That's right. Predator.

[NetNinja68]

Absolutely, The Head Radical IG Pro definitely fits this definition.

[Power Player]

Corners, great post.

[anubis]

This thread should be stickey'ed!

[dman72]

Great contributions by corners.

When is the price of the EX03 tour going to come down so I can get my 52 flex rating game on?

[corners]

Originally Posted by dman72

Great contributions by corners.

When is the price of the EX03 tour going to come down so I can get my 52 flex rating game on?

Thanks. That's the thing though - lots of players that have tried many racquets, and whose opinions I respect, agree that the Exo3 Tour is low-powered. Going by the lab data, it is, but only a little bit lower-powered than "powerful" racquets in the same weight and swingweight class. So who is right? The players or the lab data? Are players really hurt by losing the 1-2 MPH on shots struck high in the stringbed with the Exo3 Tour that they could have got with a Pure Drive? Are those 1-2 MPH that big of a deal? Do we habitually exaggerate power differences when comparing racquets? Have we been brainwashed by twenty years of marketing propaganda?

I suppose it depends on playing style and priorities. If arm health is an issue, one might gleefully give up that extra pop at the top of the stringbed. If hitting winners is most important, the marginal advantage a Pure Drive offers might be worth it. And whenever I think I should just forgot about racquet power and focus on other things - comfort, feel, precision, technique, footwork - I tend to remember Kim Clisters. I'm pretty sure she swings faster than I do, yet she used a stock Pure Drive strung with a full bed of natural gut. Just about the most powerful setup you could have. Would she have been as good using a stereotypical "control" setup, say a Prestige MP with full poly?

One additional thing that hasn't been mentioned in this thread, I think, is that the importance of a racquet's inherent power potential (ACOR, in physics terms) is greatest at low swingspeeds and becomes almost a non-issue at very fast swingspeeds. So if you're an older player with slow swings a racquet with greater inherent power will indeed give you a boost. But if you're young and quick, with swingspeeds on your groundies of 70+ mph, the inherent power of your racquet won't make much of a difference to the speed of your shots, and that 1-2 MPH difference becomes more like 0-1 MPH.

This article explains the physics of why this is the case very well: http://twu.tennis-warehouse.com/lear...ntribution.php

And finally, a shout-out to Tennis Warehouse University: Just several years ago we knew much, much less about racquets and strings than we do now. Then Tennis Warehouse hired Crawford Lindsey, the former editor of Racquet Sports Industry Magazine, and the co-author of the two definitive books on tennis science, "The Physics and Technology of Tennis" and "Technical Tennis." Lindsey is also known as the "TW Professor" and in just a couple years he has created an absolutely first class collection of articles, databases and scientific papers on racquets and strings. All of it is free, and all of it is excellent. If more people took the time to read this stuff about half the threads on the racquet forum would not exist because everyone would already know the answers.

Check it out by clicking "TW UNIVERSITY" at the top of the page.

[dman72]

Originally Posted by corners

Thanks. That's the thing though - lots of players that have tried many racquets, and whose opinions I respect, agree that the Exo3 Tour is low-powered. Going by the lab data, it is, but only a little bit lower-powered than "powerful" racquets in the same weight and swingweight class. So who is right? The players or the lab data? Are players really hurt by losing the 1-2 MPH on shots struck high in the stringbed with the Exo3 Tour that they could have got with a Pure Drive? Are those 1-2 MPH that big of a deal? Do we habitually exaggerate power differences when comparing racquets? Have we been brainwashed by twenty years of marketing propaganda?

I suppose it depends on playing style and priorities. If arm health is an issue, one might gleefully give up that extra pop at the top of the stringbed. If hitting winners is most important, the marginal advantage a Pure Drive offers might be worth it. And whenever I think I should just forgot about racquet power and focus on other things - comfort, feel, precision, technique, footwork - I tend to remember Kim Clisters. I'm pretty sure she swings faster than I do, yet she used a stock Pure Drive strung with a full bed of natural gut. Just about the most powerful setup you could have. Would she have been as good using a stereotypical "control" setup, say a Prestige MP with full poly?

One additional thing that hasn't been mentioned in this thread, I think, is that the importance of a racquet's inherent power potential (ACOR, in physics terms) is greatest at low swingspeeds and becomes almost a non-issue at very fast swingspeeds. So if you're an older player with slow swings a racquet with greater inherent power will indeed give you a boost. But if you're young and quick, with swingspeeds on your groundies of 70+ mph, the inherent power of your racquet won't make much of a difference to the speed of your shots, and that 1-2 MPH difference becomes more like 0-1 MPH.

This article explains the physics of why this is the case very well: http://twu.tennis-warehouse.com/lear...ntribution.php

And finally, a shout-out to Tennis Warehouse University: Just several years ago we knew much, much less about racquets and strings than we do now. Then Tennis Warehouse hired Crawford Lindsey, the former editor of Racquet Sports Industry Magazine, and the co-author of the two definitive books on tennis science, "The Physics and Technology of Tennis" and "Technical Tennis." Lindsey is also known as the "TW Professor" and in just a couple years he has created an absolutely first class collection of articles, databases and scientific papers on racquets and strings. All of it is free, and all of it is excellent. If more people took the time to read this stuff about half the threads on the racquet forum would not exist because everyone would already know the answers.

Check it out by clicking "TW UNIVERSITY" at the top of the page.

I tried all the different variables on the shot speed calculator, and it seems like overall no matter what the speed of the stroke, the racquet does not make a huge difference...plug in a serve returned by a 15 mph volley, and the difference between a pure drive and an EX03 tour is 1 or 2 MPH.

[ChicagoJack]

Originally Posted by marosmith

So does anyone disagree with chicagojacks (even if it is recycled) information or conclusions? And if so can they provide research which would contradict it?

Hi marosmith,

1. Cool man, I invite you to hang onto that healthy skepticism. On any any given day, the volume of baseless assumptions, contradicting player experience, and questionable sources is pretty high around this ranch.

2. Having said that, what you are calling "recycled information", I would simply describe as "widely available published research" I'm just trying to explain the basics here, which ought to be no big whups. As it turns out, the truth is often stranger than fiction, not very intuitive at times, not widely known, and is often not accepted and derided by even the most avid racquet junkies.

3. It has been also been implied (by someone else a few posts ago) I'm procuring information from a single book. That's not the case. That's actually kind of funny, as I often take a fair amount of heat for providing too many sources and links, which I'm happy to provide here. Lots of good reading in there, feel free to fact check and cross reference. It's all good.



The Really, Really, Short Version, Basics Of Racquet Power, ACOR:
(More Detail, Screen Grab Photos On My Posts #12, 13, 24, 34)

1. Ball velocity is the only measurable indicator of racquet power. On the court, ball velocity is typically measured with a radar gun and expressed as MPH or KPH. In laboratory conditions we might also measure film frames or measure bounce heights. However, recreational players don't often play with radar guns court side, so we often are using visual cues such as depth, trajectory, and height over the net to make guesses about ball speed. The problem is that all of these visual cues are highly sensitive to changes in string pattern, string tension, string type, and technique. Here are a just few examples: An open pattern and or slippery strings creates a higher arc, than a denser patterns or sticky strings, given the same stroke. If the player does not adjust to the additional height over the net, the ball might land deeper in the court, not because the ball is traveling faster, but because it is simply launching at a higher angle. However, if the player adjusts to the high arc by closing the racquet face, the result will be more spin. If the player now sees the ball diving into the court with more spin, and several feet to spare, this might create yet another stroke adjustment, wherein the player begins to open up his technique, will swing faster and with more confidence. The result of that 2nd adjustment would be even more spin and more ball speed.

2. All things being equal : A higher swingweight frame has more power. This assumes the swingspeed does not drop, which is easier said than done. [1][2][3][5][6]

3. Racquet power is almost directly related to swingweight. It is the single most predictable indicator of racquet power when attempting to distinguish inherent power levels between different types of racquets. [2][5][6]

4. In general : a stiffer frame is slightly more powerful than a flexible one. However, a flexible frame is just as powerful as a stiff frame when you hit the center of the strings. Stiffer frames have slightly more power when the ball is struck hit near the tip of the racquet. [1][2][5][6]

5. All things being equal : A racquet with a bigger head has more power. If the string tension remains constant, the longer strings creates a softer string bed overall. A softer string bed creates a more powerful racquet. There are limits to this however, as you cannot play tennis with a butterfly net. [1][6]

6. All things being equal: A racquet with a wider head will have more twistweight. This creates more power on balls that miss the sweet spot near the sides of the frame.[5][6] For additional insight on wide heads and spin, see link [4]

7. If you add length to an existing frame, swingweight increases dramatically, and with it so does power. However, since added length dramatically reduces manuververability, racquet companies typically factor that into the equation by lowering the balance point, which creates fewer units of swingweight per overall weight, in mass produced extended length frames.[1][2][6]

Quote 3: "Racquet stiffness has no effect on power when the ball is struck in the middle of the strings, but stiff racquets are more powerful when the ball is struck nearer the tip of the racquet"
-- Rod Cross, Chapter 14, Racquet Power, The Physics And Technology Of Tennis. Link [6]



References, Links, Suggested Reading:

Link [1] Basic Facts about Frames and Strings,
The United States Racquet Stringers Association
http://www.racquettech.com/top/basic_facts.html
http://www.tennis-warehouse.com/lc/basicfacts.html

Link [2] Raw Racquet Power, By Rod Cross
http://www.racquetsportsindustry.com...uet_power.html

Link [3] Racquet Handle Weighting And Maneuverablility, by Rod Cross
http://www.racquetsportsindustry.com...ing_and_m.html

Link [4] The Inch That Changed Tennis Forever, By Rod Cross
http://www.racquetsportsindustry.com..._tennis_f.html

Link [5] Racquet Power Comparison Tool
http://twu.tennis-warehouse.com/cgi-...mparepower.cgi

Link [6] The Physics And Technology Of Tennis
http://www.tennis-warehouse.com/The_...e-PHYSICS.html

Link [7] Mark Philippoussis Service Speed Testing:
Averages 124 MPH with a Wood Racquet, and 126 with his Graphite Racquet,
Time Magazine, June 2009
http://www.time.com/time/magazine/ar...899876,00.html

Link [8] Power Potential, The Total Performance Measurement
http://twu.tennis-warehouse.com/lear...erformance.php

Link [9] The Ingredients Of Maximum Shot Speed
http://twu.tennis-warehouse.com/lear...xspeedeasy.php

Link [10] Maximum Shot Speed, Where to Hit on the Racquet
http://twu.tennis-warehouse.com/lear...xshotspeed.php

Link [11] Why Is Maximum Power In the Throat and Maximum Shot Speed Toward The Tip?
http://twu.tennis-warehouse.com/lear...PPandspeed.php

Link [12] Compare Racquet Shot Speeds (Mph)
http://twu.tennis-warehouse.com/cgi-...mparespeed.cgi

Link [13] Compare Racquet Trajectories
http://twu.tennis-warehouse.com/cgi-...ry_compare.cgi

Link [14] More Tennis Physics, Rod Cross
http://www.physics.usyd.edu.au/~cros...entations.html

Link [15] Power, Does the Racquet Matter?
http://twu.tennis-warehouse.com/lear...ntribution.php

Link [16] Power Potential Test Procedure
http://twu.tennis-warehouse.com/lear...est_method.php

PS - Corners, thanks for chiming in.. I was hoping you might swing by and contribute.

- Jack

[mikeler]

As a former user of stiff frames and now an Exo Tour user, I can't believe the difference between a Pure Drive and the Exo with exactly the same string at the same tension is only 1-2 MPH. I'd say it is a few more MPH than that just based upon my own observations (no hard measurements).