PDA

View Full Version : Does a heavy frame's low flex significantly cancel out its power?


MAXXply
03-14-2012, 12:44 AM
I mean, if heavy rackets are said to be more capable of providing power due to their inherent mass, is that potential negated by soft-playing flexibility? Does significant flexibility cancel out and reduce that power? I'm talking rackets in the vicinity of under 60RA, like the Prince Rebels, EXO Tours etc.

gloumar
03-14-2012, 02:08 AM
I mean, if heavy rackets are said to be more capable of providing power due to their inherent mass, is that potential negated by soft-playing flexibility? Does significant flexibility cancel out and reduce that power? I'm talking rackets in the vicinity of under 60RA, like the Prince Rebels, EXO Tours etc.

I used to play these prince and other rackets with such a good heft and flex at the same time (prince graphite pro, dunlop 200, pro staff rok, etc).

From my experience (nothing scientific about this) the main thing is that apart of stability, heft brings much power with the good swing, and the good racquet speed. If you got that, at contact flex will bring you more control and comfort, but will not reduce pace so much imo.
The way you swing the racquet is very much of the power issue, I would say. For example I generate a good power with my ozone tour, despite the good flex and the not so heavy weight, beacuse of the very maneuvrable racquet that allows me to give a lot of speed on the head.

I'd say to try to sum-up that on good agressive strokes, flex will not drop power down in comparison to a stiff racquet, but it will maybe do more on defensive shots, when you want the racquet to be powerful by itself, because flex does not help with forgiveness... But heft still does !! (check on TW university), and I guess in these situations heft is still the main thing :)

spaceman_spiff
03-14-2012, 03:09 AM
No. Go to TWU and check the power information for the BB11 SE. Despite its tight sting pattern and soft flex, it still has very high power ratings because of its swingweight (static weight isn't huge, but the swingweight is over 370).

Obviously, it would be even more powerful if it had an open string pattern and stiffer beam, but those are minor factors compared to the amount of mass in the head.

MAXXply
03-14-2012, 04:17 AM
I agree Gloumar there's nothing like that hefty feeling in your hand that inspires you to deliver a heavy ball. I'm playing the old Rebel 95 at the moment and its combination of heft, balance and 18x20 instills that big-hitting confidence. However it's its soft response that makes me feel the result doesn't correspond with the level of effort put in...what the heck, maybe I should just lift some weights for a few weeks before re-assessing it.

Don't Let It Bounce
03-14-2012, 06:10 AM
I mean, if heavy rackets are said to be more capable of providing power due to their inherent mass, is that potential negated by soft-playing flexibility?For what it's worth, the USRSA power index is calculated like this: length index headsize flex swingweight 1000. (Length index: 27" = 1.0, 27.5" = 1.05; 28" = 1.1)

Almost all available rackets fall within a fairly narrow range of flex (60 to 72, more or less). The range of available swing weights is much greater. You could interpret that to mean that swing weight has a bigger impact on overall power than flex, I suppose.

But, the power that comes from swing weight seems to me to be qualitatively, as opposed to quantitatively, different from the power that comes from high stiffness. I guess I'd describe it roughly as a more controllable power, and perhaps as a more neutralizing (of the other guy's power) sort of power.

fuzz nation
03-14-2012, 07:24 AM
I agree that "power" isn't just one thing when talking about gear or the way that we're hitting the ball.

A racquet with more stiffness than a similar frame with extra flex will typically deliver more "pop" at contact. For me, that can be a good thing when I want some good zing on my volleys, serves, and serve returns. A more compact motion can effectively punch the ball around the court - that can be great for doubles.

The downside of that stiffer, livelier frame can be a less predictable response with full strokes (less consistency and control). A slight off-center hit with it can be rather dull, but a similar swing that catches the ball square in the sweet-spot can be too hot to keep down on the court. Even though a softer racquet with a little less pop might deliver a somewhat diminished response, it's extra control can let me hit harder and still land my shots.

So while that stiffer frame might seem to have more power in terms of extra pop, the softer alternative can enable me to play with more power. My favorite doubles racquets are my heavy, stiff 6.1 Classics, but I can play with more power and consistency in a singles format with other frames that are at least as hefty, but much more flexible.

I can hit my hardest strokes with some very heavy and very flexible mids in my collection, but if I'm not in good form, these things are too heavy for me. So there's the catch in terms of weight: greater power potential is nice in a heavier racquet... as long as I can actually use it.

Muppet
03-14-2012, 08:09 AM
I have a theory about this. It has to do with the dwell time that the ball will sit on a racquet. If a racquet is stiff, the ball will pop off of it relatively quickly compared to a softer racquet. During the extra dwell time of the softer racquet, the player will be putting more effort into the ball. This can more than make up for the extra stiffness in the other racquet, depending on how much the player compensates during the dwell time. Even with an even stroke, the ball receives power for an extended moment.

It may seem like the difference in player input during dwell time is insignificant, but I think it is more significant than the difference in racquet stiffness. And it goes back to player preference. Do you like a more crisp racquet that hits very consistently and efficiently? Or do you like a flexier racquet that will offer more of a "window of control", where you can direct the ball, adjust the pace, and add spin? Not to say that a stiff racquet doesn't offer these things, but the flexy racquet does have that extra window of control.

fuzz nation
03-14-2012, 12:44 PM
In case you haven't seen it Muppet, there's a thread going in the "Tips/Instruction" section titled "Interesting Tennis Ballistics" (there are actually two parts to it now). You might enjoy a look at that and see how the theories there mesh with what you're working with now. I'm still trying to figure this stuff out for myself.

As I understand things, the ball rebounds off the strings while the racquet is still flexing away from the ball, but that actual rebound happens in roughly the same few milliseconds. Since a stiffer frame isn't bending away from the ball as much as a softer alternative when the ball hits the strings, there's a little more efficient rebound action with the stiffer racquet. I think of that as the difference between throwing a ball forward while slowly walking backward (stiffer racquet) and throwing a ball forward while running backward (softer racquet).

Since that softer frame has a less violent rebound, that makes the less lively response easier to control, at least for me. As far as the actual time of interaction between the ball and the strings, I've heard some conflicting ideas, but some arguments strongly support that there's virtually no difference in the contact time between stiffer and softer frames. The cool thing would be finding ultra slow-motion footage posted on youtube that showcases this comparison. I guess I'll get searching for that one...

corners
03-14-2012, 12:58 PM
For what it's worth, the USRSA power index is calculated like this: length index headsize flex swingweight 1000. (Length index: 27" = 1.0, 27.5" = 1.05; 28" = 1.1)

Almost all available rackets fall within a fairly narrow range of flex (60 tp 72, more or less). The range of available swing weights is much greater. You could interpret that to mean that swing weight has a bigger impact on overall power than flex, I suppose.

But, the power that comes from swing weight seems to me to be qualitatively, as opposed to quantitatively, different from the power that comes from high stiffness. I guess I'd describe it roughly as a more controllable power, and perhaps as a more neutralizing (of the other guy's power) sort of power.

The USRSA Power Index was invented before a whole bunch of empirical evidence on actual racquet "power" was collected over the past three years, by one of the people who invented the Index, TW's own Professor. His data shows that stiffness was greatly overrated in the USRSA formula. Manufacturer's sell sticks on stiff=power because that's all they can manipulate to give any free power. Racquet power is really dependent on swingweight, but swingweight also limits swingspeed, so it is a wash and really comes down to stroke mechanics and what works best for your game.

Stiffness can be increased without making the frame more difficult to swing, so any power gains you get with increased stiffness is free, in that sense (your joints may disagree). But a recent scientific paper showed that you would have to triple the stiffness of your racquet (from RDC 60 to RDC 180!) to get an extra 4-5 miles per hour on your shots. The conclusion I've come to is that stiffness is one of the last things I'm going to think about if I want more pop. 1st would be improving my strength and technique, second would be switching to a softer, more powerful string, with gut being the best, of course. I don't care for the feel of stiff frames, and feel trumps power, at least in my book and at my recreational level of play.

cknobman
03-14-2012, 01:28 PM
My answer is not scientific in any way.

I believe a flexible racquet has noticeably less power than an exact same spec'd racquet with less flex.

Muppet
03-14-2012, 01:51 PM
I don't believe racquets have any power. I'd say that stiffer racquets use the player's power more efficiently and flexible racquets give the player the opportunity to put more mustard on the ball.

gloumar
03-14-2012, 01:55 PM
length index headsize flex swingweight 1000.

I can see that it doesn't consider the strign pattern ! Weird, ins't it ? Because the string density is a important parameter , right ?

And it's maybe what lacks a bit in your Rebel95, MAXXPly : a bit more vivacity from the stringbed ? I'd blame the 18*20. Try an TOUR 16*18, or an old Prince graphite in 14*18 :D You'll see quite a difference ! It will suddenly be very.... lively ? :)

I guess these very open patterns are dropped because it uses alot of string, but that's a shame !

Muppet
03-14-2012, 02:05 PM
In case you haven't seen it Muppet, there's a thread going in the "Tips/Instruction" section titled "Interesting Tennis Ballistics" (there are actually two parts to it now). You might enjoy a look at that and see how the theories there mesh with what you're working with now. I'm still trying to figure this stuff out for myself.

As I understand things, the ball rebounds off the strings while the racquet is still flexing away from the ball, but that actual rebound happens in roughly the same few milliseconds. Since a stiffer frame isn't bending away from the ball as much as a softer alternative when the ball hits the strings, there's a little more efficient rebound action with the stiffer racquet. I think of that as the difference between throwing a ball forward while slowly walking backward (stiffer racquet) and throwing a ball forward while running backward (softer racquet).

Since that softer frame has a less violent rebound, that makes the less lively response easier to control, at least for me. As far as the actual time of interaction between the ball and the strings, I've heard some conflicting ideas, but some arguments strongly support that there's virtually no difference in the contact time between stiffer and softer frames. The cool thing would be finding ultra slow-motion footage posted on youtube that showcases this comparison. I guess I'll get searching for that one...

It sounds to me here like you are talking about stationary racquets. In practice, the player times his stroke to work well with the impact.

The question for me remains is how much more "oomph" is the player with the flexy stick providing? The stiffer raquet is certainly more powerful per se. But the flexible racquet/player system can be more powerful.

Thanks for the reference to Tips/Instruction. I'll check it out.

gloumar
03-14-2012, 02:15 PM
It sounds to me here like you are talking about stationary racquets. In practice, the player times his stroke to work well with the impact.

The question for me remains is how much more "oomph" is the player with the flexy stick providing? The stiffer raquet is certainly more powerful per se. But the flexible racquet/player system can be more powerful.

Thanks for the reference to Tips/Instruction. I'll check it out.

As flex brings dwelltime and therefore control and spin ability, allowing to swing harder ? Is that what you mean ? I would really agree.
But it's no more a question of the racquet's power itself, for sure ;)

Muppet
03-14-2012, 03:56 PM
As flex brings dwelltime and therefore control and spin ability, allowing to swing harder ? Is that what you mean ? I would really agree.
But it's no more a question of the racquet's power itself, for sure ;)

I would say that the flexy stick does allow for a harder swing, and within this dwell time more pace can be imparted to the ball. The extra ball speed would need to be controlled somehow, but the method of control does not create the extra power. And that same hard swing would create uncontrollable power in a stiff stick.

LeeD
03-14-2012, 04:05 PM
One thing few mention is the fact a dropped ball can be hit hard with a light racket, but a fast incoming ball needs a heavier racket to impart the pace.
So not all "balls" are the same.
If you can't swing a heavy racket fast, it doesn't impart power.
If you're swinging a superlight racket very fast, it won't impart power to an INCOMING ball that is a fast mover.
OTOH, a superlight racket can SMACK a slow moving ball very easily.

corners
03-14-2012, 04:05 PM
As I understand things, the ball rebounds off the strings while the racquet is still flexing away from the ball, but that actual rebound happens in roughly the same few milliseconds. Since a stiffer frame isn't bending away from the ball as much as a softer alternative when the ball hits the strings, there's a little more efficient rebound action with the stiffer racquet. I think of that as the difference between throwing a ball forward while slowly walking backward (stiffer racquet) and throwing a ball forward while running backward (softer racquet).

Since that softer frame has a less violent rebound, that makes the less lively response easier to control, at least for me. As far as the actual time of interaction between the ball and the strings, I've heard some conflicting ideas, but some arguments strongly support that there's virtually no difference in the contact time between stiffer and softer frames. The cool thing would be finding ultra slow-motion footage posted on youtube that showcases this comparison. I guess I'll get searching for that one...

The racquet does not rebound brfore the ball leaves the strings. It's possible to get a setup where it does, but you'd have to have a frame stiffer than anything on the market, probably about 90 RDC, and string with gut to keep the ball on the strings long enough for the super-stiff frame to snap back. I'd love to try it, but the only way I can think of doing it would be by cutting an inch off the butt of the stiffest frame available (shorter frames are stiffer). Because this does'nt happen though is why stiffness is relatively trivial to "power". Stiff heads do give a bit more speed of shot on off-center shots, but I would describe that as forgiving, not powerful. The only place where stiffness does give a power advantage is near the top of the hoop, so if you hit serves there you might get a couple extra miles per hour by switching to a frame with high hoop stiffness. (Pure Drives and clones are good examples of this.)

For those that doubt how trivial stiffness is, just consider the wood vs. graphite serve speed comparison Tennis magazine did with Sampras and the Scud several years ago. 60+ RDC vs. sub-30 RDC and the differance in serve speeds was only about 3 mph.

LeeD
03-14-2012, 04:09 PM
I agree, a stiff racket vs a super noodle doesn't make all that difference in actual ball speed, BUT..... A stiffer more aero racket might make you want to serve fast, in practice, in matches, by it's FEEL. A heavier softer racket might discourage you to practice fast serves, and hard shots, so you don't practice the big winners as often.
Tennis is as much a mental game as a physiical one.

corners
03-14-2012, 04:52 PM
I agree, a stiff racket vs a super noodle doesn't make all that difference in actual ball speed, BUT..... A stiffer more aero racket might make you want to serve fast, in practice, in matches, by it's FEEL. A heavier softer racket might discourage you to practice fast serves, and hard shots, so you don't practice the big winners as often.
Tennis is as much a mental game as a physiical one.

Yeah, I agree. And it seems from watching people on these boards go through the demo/racquet obsession process that feel often ends up trumping the measurables.

kaiser
03-15-2012, 03:27 AM
I agree, a stiff racket vs a super noodle doesn't make all that difference in actual ball speed, BUT..... A stiffer more aero racket might make you want to serve fast, in practice, in matches, by it's FEEL. A heavier softer racket might discourage you to practice fast serves, and hard shots, so you don't practice the big winners as often.
Tennis is as much a mental game as a physiical one.

It might, but it might also be the other way around. Mental, you know...

bluegrasser
03-15-2012, 05:45 AM
In watching both Andujar & Granollers ( Prince tour ) who use the same flexy frames, the ball seems to have a delayed response, but come off with mega pop. The ball also seems to have major spin, more than most, except Nadal of course.

fuzz nation
03-15-2012, 05:55 AM
Good stuff there, corners... again!

Having used the Volkl C10's for a while now, I can certainly agree on that aspect of stiffness making for more response up toward the top of the string bed. These frames have a softer hoop than others, which makes them notoriously "tip dead", but I've learned to get along with it okay.

I don't think I had either a stationary or moving ball in mind in my post, but you got me thinking more about the difference between shots where my racquet is moving with more of a full swing compared with others where my racquet carries less velocity into the ball. It seems that a stiffer frame can be a better option for me when I want to "punch" the ball around the court, let's say in a typical doubles setting with lots of net play. When I'm hitting more full strokes from the baseline, I really like the personality of a softer racquet.

In either case though, I don't feel right if my racquet is too light and unstable for my tastes. It could easily be the case that my brain, tiny as it may be, is more hung up on the feel of a softer or stiffer racquet, depending on the setting, than the actual nuts 'n bolts physics of the collision. More coffee while I think it over...

MAXXply
03-15-2012, 07:07 AM
I agree with Muppet's theory (post#7 above). "Dwell time" on the strings feels especially noticeable on my 20-21mm Rebel 95, accentuated by the 18x20 pattern. These semi-wide frames impart (for me) a slight feeling of momentary delay at impact, as if my POG-attuned senses are still used to that close-feeling you get from hitting with a sub-19mm thin beam racket. Using a 20-21mm frame - indeed any wide frame - feels a bit further away.

Muppet
03-15-2012, 01:43 PM
I'm thinking about it the other way now. 3 of my 4 racquets are fairly flexible. I can swing them more slowly and the racquet puts more work on the ball during the extra time the ball is on the strings.

I mean work literally: work = force x distance

And I'm pretty sure I'm compensating for the deflection of the racquet with the angle that I hold the racquet face to the ball. I think our racquets teach us how to wield them through impact.

li0scc0
03-15-2012, 02:13 PM
But a recent scientific paper showed that you would have to triple the stiffness of your racquet (from RDC 60 to RDC 180!) to get an extra 4-5 miles per hour on your shots. The

That paper may have shown this, but subjectively I find this to be false.
My shots increase at least 10-15mph on serve and groundstrokes with the same effort if I use a 12 ounce, 330SW 95-98 square inch racquet with 70-73 flex vs. a 12 ounce, 330SW, 95-98 square inch racquet with 60 flex.

LeeD
03-15-2012, 03:05 PM
Wow, that's a lot. You'd think EVERY pro would use a stiffer racket, but reality suggests....... maybe closer to 3-5 mph.
In a few serving contests back in the day, my playing racket was a soft ProStaffKramer, the softest except Evert woods. My serving racket was the stiff GreenYonexOPS. Difference in measured serve speed? 5mph, closer to 4. I switched from KramerProStaff to Yonex, my results rising dramatically, but actually, it was in my head.

Muppet
03-15-2012, 06:07 PM
This calls to mind my serving performance when I've used stiffer racquets. I used to have a tweener and I now have an RA 63 Aerogel 200. They both have given me much easier timing for my serve. And perhaps more power, but it's tough to sort out the beam's stiffness from improved timing. I think it was the timing that did it for me.

Muppet
03-16-2012, 09:23 AM
Returning to ground strokes, I guess it's more a question of two identical racquets, except one stiff and one flexible, each swinging through different dwell zones at the same racquet speed. I'm assuming that the flexible racquet's player doesn't put in more racquet speed, but he/she can manipulate the racquet to account for racquet deflection from the ball's impact.

Does: stiff racquet work on ball = flexible racquet work on ball

The stiff racquet puts a short burst on the ball.
The flexible racquet presses on the ball less for a longer moment.

If all of the other variables, such as string type and tension, can be controlled to test only the flex of the racquets, I would say that energy is conserved and the real world difference is minimal.

But I do think that players with flexier racquets do take the opportunity to feed more power into the shot during the extended dwell time, also using the racquet's flex to add control.

fuzz nation
03-16-2012, 01:42 PM
My impression of the higher degree of control on strokes with the softer frame works like this. Hopefully it's at least half-way right because it makes too much sense to me to chuck it.

Any racquet puts both linear velocity and spin into the ball at contact and if we swing both the stiffer and the softer frame at the same speed and through the same path to the ball, they produce roughly the same amount of spin. But since the energy return of the stiffer racquet puts a little more velocity on the ball, that shot has relatively less spin to act upon it.

The softer racquet produces a little less velocity from that same swing, but just as much spin. That makes it easier to turn the ball over and keep it on the court; the same amount of spin can have a greater effect on a slower ball.

When I think of how a more flexible racquet can help with producing a higher ratio of spin to linear velocity on the ball, it makes sense to me that less resilient poly strings are also useful for adding an aspect of control to a stiffer racquet, since those strings have less elasticity. Installing them in any racquet will also tilt that ratio toward more spin - although the actual spin is the same with a given stroke, there's less linear velocity on the ball, so that spin can better control it. Swing harder to get more velocity and you also get a lot more spin.

corners
03-16-2012, 04:13 PM
Good stuff there, corners... again!

Having used the Volkl C10's for a while now, I can certainly agree on that aspect of stiffness making for more response up toward the top of the string bed. These frames have a softer hoop than others, which makes them notoriously "tip dead", but I've learned to get along with it okay.

I don't think I had either a stationary or moving ball in mind in my post, but you got me thinking more about the difference between shots where my racquet is moving with more of a full swing compared with others where my racquet carries less velocity into the ball. It seems that a stiffer frame can be a better option for me when I want to "punch" the ball around the court, let's say in a typical doubles setting with lots of net play. When I'm hitting more full strokes from the baseline, I really like the personality of a softer racquet.

In either case though, I don't feel right if my racquet is too light and unstable for my tastes. It could easily be the case that my brain, tiny as it may be, is more hung up on the feel of a softer or stiffer racquet, depending on the setting, than the actual nuts 'n bolts physics of the collision. More coffee while I think it over...

Thanks! Yeah, stiffness does give just a bit more pop, in terms of ACOR - or "power potential", especially at the top of the hoop. At high swing speeds, racquet speed overwhelms any small differences in power potential, which is why the woody serves only a couple mph slower than the modern graphite racquet. If you're swinging fast, the racquet just doesn't make a huge difference to speed of shot. But on volleys and blocked returns, or for people that don't swing fast on any shots, the racquet contributes a larger amount to the resulting shot speed. I think stiffer racquet give better directional control on volleys too, while a flexible racquet, because it holds the ball a bit longer on the strings, actually helps many people control the ball on groundies and serves.

If you watch the super-slow footage of Federer you see his frame wobble quite a bit in the upper hoop, especially on serves where he hits a bit higher in the stringbed. Could he get a couple extra mph on his serve with a Pure Drive leaded to his specs? Probably, but he must feel the trade-offs wouldn't be to his advantage.

li0scc0
03-16-2012, 04:26 PM
Wow, that's a lot. You'd think EVERY pro would use a stiffer racket, but reality suggests....... maybe closer to 3-5 mph.
In a few serving contests back in the day, my playing racket was a soft ProStaffKramer, the softest except Evert woods. My serving racket was the stiff GreenYonexOPS. Difference in measured serve speed? 5mph, closer to 4. I switched from KramerProStaff to Yonex, my results rising dramatically, but actually, it was in my head.

Do you think pros really WANT more power? I have hit with a challenger tour player, serves 135+ with a Prince EXO3 Tour 16x18. Hit some serves with a Pure Drive Roddick that one needed slo-mo cameras to see!
Problem is...his groundstrokes did not stay in the court.
If pros WANTED more power, they would be using high stiffness plus natural gut.

corners
03-16-2012, 04:46 PM
Do you think pros really WANT more power? I have hit with a challenger tour player, serves 135+ with a Prince EXO3 Tour 16x18. Hit some serves with a Pure Drive Roddick that one needed slo-mo cameras to see!
Problem is...his groundstrokes did not stay in the court.
If pros WANTED more power, they would be using high stiffness plus natural gut.

Yes, they want more power, but switching to gut isn't the way to do it because it provides a bit less spin. The way the pros hit now they can control any amount of spin by varying spin and shot trajectory. If they could get a racquet that gave them an extra 5 mph on serve without losing any feel they would take it. On rally shots they could usd less energy, on heavy spin shots they would have the same amount of spin and control but the shot would be travelling faster and be more difficult to return. And when they had an opening for a winner, rather than hit flat they could hit with moderate spin, increasing margin for error, but still hit just as fast a ball as if they hit flat with their old racquet. Pros using "low power" racquets is a myth, IMHO. Pros use control racquets: relatively heavy, high swingweight, generally flexible. But high control does not necessarily equal low power. Think of Nadal. I've seen people on these boards say the APD is too powerful for their game. Sounds like BS when you consider that Nadal swings 30 mph faster than them and can keep it in the court just fine.