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View Full Version : Do Rackets Degrade Over Time


kenshireen
01-26-2008, 04:31 PM
This is an important issue and I would appreciate someone who understands the physics of graphite/glue etc to give me some advice... I like to use older rackets but sometimes I'm told that the carbon fiber breakdown over time. Is this fact or fiction... Is there any science to this...
Is it the number of times a racket is strung that determines frame integrity.

Thanks you

cadfael_tex
01-26-2008, 04:36 PM
Can't give you a scientific answer but I asked the same question a couple of years ago and have some anecdotal evidence. I had an old Head Graphite Director that I was sure was 'dead'. I played out with string tensions and if it wasn't so darn heavy would probably be my favourite racquet. Not dead at all after 20 plus years.

blubber
01-26-2008, 05:53 PM
Every time you hit the ball fibers in the racquet are breaking. This especially the case for advanced players that hit big.

Stringing is very hard on frames as well. Racquets are under the most stress when they are being strung.

So if you have a frame that has been strung many times and has been used often then the racquet will play dramatically different from a new version of that racquet. It will be less stiff and more flexy.

However, it's all about what you like. As long as the racquet is still structurally sound you can still use it. Some people like a dead, lossey goosey feeling.

Do a search this has been discussed many, many times.

Bud
01-26-2008, 06:25 PM
Every time you hit the ball fibers in the racquet are breaking. This especially the case for advanced players that hit big.

Stringing is very hard on frames as well. Racquets are under the most stress when they are being strung.

So if you have a frame that has been strung many times and has been used often then the racquet will play dramatically different from a new version of that racquet. It will be less stiff and more flexy.

However, it's all about what you like. As long as the racquet is still structurally sound you can still use it. Some people like a dead, lossey goosey feeling.

Do a search this has been discussed many, many times.

Would you mind posting your evidence of this? You speak like it's a scientific or widely accepted fact.

I continue hearing members here stating this 'fact' yet no one has produced any evidence.

jayserinos99
01-26-2008, 07:26 PM
I can't seem to find the exact information, but one small example is Guga, who happens to like his frames strung a certain amount of times before he plays with them. He'd like them broken in before he uses them in a match.

Nellie
01-26-2008, 09:09 PM
Would you mind posting your evidence of this? You speak like it's a scientific or widely accepted fact.

I continue hearing members here stating this 'fact' yet no one has produced any evidence.

What do you really want - there is ample evidence that carbon fiber breaks down from stress (actually that the resin breaks down) Do you really want technical papers on how carbon fiber airplanes parts and bicycle frames deteriorate?

I do not know of someone who has taken the time and money to photograph racquet samples under large magnefication.

In fact, I don't really care, except that I can feel the racquets changing after a while. If you old racquet works well, then power to you.

racquet_jedi
01-26-2008, 11:15 PM
Would you mind posting your evidence of this? You speak like it's a scientific or widely accepted fact.

I continue hearing members here stating this 'fact' yet no one has produced any evidence.

Here's your proof...

"And if you string with a hybrid, all at the same tension, keep in mind that the crosses will be tighter than the mains since they’re shorter. Plus, during stringing, as the cross strings are pulled through the main strings they loosen the mains slightly. In the end, customizing your racquet may not be enough. Each time you hit a ball, you break racquet fibers. Though there may not be a visible crack in the frame, a racquet will eventually start to feel dead. Most pros go through 50 to 70 racquets a year. In his playing days, Andre Agassi used about 100 annually. If your racquet feels dead, or “soft,” you might need an upgrade."

http://tennis.com/yourgame/gear/general/general.aspx?id=96506

Bud
01-26-2008, 11:24 PM
Here's your proof...

"And if you string with a hybrid, all at the same tension, keep in mind that the crosses will be tighter than the mains since they’re shorter. Plus, during stringing, as the cross strings are pulled through the main strings they loosen the mains slightly. In the end, customizing your racquet may not be enough. Each time you hit a ball, you break racquet fibers. Though there may not be a visible crack in the frame, a racquet will eventually start to feel dead. Most pros go through 50 to 70 racquets a year. In his playing days, Andre Agassi used about 100 annually. If your racquet feels dead, or “soft,” you might need an upgrade."

http://tennis.com/yourgame/gear/general/general.aspx?id=96506

How is that scientific. It's a tennis magazine with advertisers that are trying to sell racquets. It doesn't list sources or any reference section to verify the statements. Also, a player is not a scientific source. What they are feeling, when they state a racquet is dead, may be their imagination.

I'm talking a genuine scientific study or journal article with evidence (i.e. miscroscope slides showing broken carbon or fiberglass fibers increasing in number over time, etc.) If someone knows of such a study, please link to it or send me a copy so I can read it. I've yet to see one.

Bud
01-26-2008, 11:30 PM
What do you really want - there is ample evidence that carbon fiber breaks down from stress (actually that the resin breaks down) Do you really want technical papers on how carbon fiber airplanes parts and bicycle frames deteriorate?

I do not know of someone who has taken the time and money to photograph racquet samples under large magnefication.

In fact, I don't really care, except that I can feel the racquets changing after a while. If you old racquet works well, then power to you.

I care. That's why I posted. If you really don't care, don't respond to the post.

It seems someone would have studied this. There may be evidence that carbon fiber/resin breaks down in airplane parts or bicycle frames but I want to see if, at what rate and to what degree that deterioration occurs when applied to a tennis racquet... i.e. how long it actually takes until a tennis racquet deteriorates to the point that a change is noticeable to a player.

jayserinos99
01-26-2008, 11:34 PM
How is that scientific. It's a tennis magazine with advertisers that are trying to sell racquets. It doesn't list sources or any reference section to verify the statements. Also, a player is not a scientific source. What they are feeling, when they state a racquet is dead, may be their imagination.

I'm talking a genuine scientific study or journal article with evidence (i.e. miscroscope slides showing broken carbon or fiberglass fibers increasing in number over time, etc.) If someone knows of such a study, please link to it or send me a copy so I can read it. I've yet to see one.

I am not a chemical or materials engineer, but just doing a search I found these links.

http://jcm.sagepub.com/cgi/content/abstract/36/24/2713

http://books.google.com/books?id=FHoBkd6PGXUC&pg=PA113&lpg=PA113&dq=carbon+fiber+deteriorate+epoxy&source=web&ots=99X4QYdiR-&sig=z6xYpT-dpbfh1UYca-aP21noJuI#PPA104,M1

Bud
01-26-2008, 11:38 PM
I am not a chemical or materials engineer, but just doing a search I found these links.

http://jcm.sagepub.com/cgi/content/abstract/36/24/2713

http://books.google.com/books?id=FHoBkd6PGXUC&pg=PA113&lpg=PA113&dq=carbon+fiber+deteriorate+epoxy&source=web&ots=99X4QYdiR-&sig=z6xYpT-dpbfh1UYca-aP21noJuI#PPA104,M1

Thanks Jay, I'll check them out.

Deuce
01-27-2008, 12:07 AM
Here's your proof...

"And if you string with a hybrid, all at the same tension, keep in mind that the crosses will be tighter than the mains since they’re shorter. Plus, during stringing, as the cross strings are pulled through the main strings they loosen the mains slightly. In the end, customizing your racquet may not be enough. Each time you hit a ball, you break racquet fibers. Though there may not be a visible crack in the frame, a racquet will eventually start to feel dead. Most pros go through 50 to 70 racquets a year. In his playing days, Andre Agassi used about 100 annually. If your racquet feels dead, or “soft,” you might need an upgrade."

http://tennis.com/yourgame/gear/general/general.aspx?id=96506
Again - this is simply an attempt by Tennis Magazine to cater to their advertizers - nothing more.
Telling gullible people that pros go through dozens of frames per year, and then stating that "you might need an upgrade"... pure slight of hand.

No-one needs to know when or if a racquet "goes dead".
All anyone needs to know is if a racquet feels comfortable, and if it performs efficiently for them. Doesn't matter if the racquet is brand new, or if it's been used every day for 20 years.

jazar
01-27-2008, 02:55 AM
if you are a good player playing regularly then your rackets will lose 7-10% of their stiffness within the first year. after that the loss gets less. i've been using my rackets for about 5 years now and i can definitely feel they have softened, but i really liken that kind of feel

____
01-27-2008, 07:49 AM
During Sampras' career,Do you think he recieved 100 of rare St.Vincent Prostaff 85?

I dont think so.

I think he probably got as many as 20 frames and as we all know that he restrung all his racquets everyday.

Did Sampras use dead racquets all along?

I dont think so.


From Sampras case,I think racquets dont degrade overtime

racquet_jedi
01-27-2008, 10:19 AM
Sampras strung his racquets at about 15 lbs over the "recommended" tension. With that much tension, his racquets would certainly break eventually...

Sampras was sponsored by Wilson, during his prime, he may or may have not been one of the most, if not the most, important client that Wilson had...

If he wanted new racquets, Wilson could certainly make them...

Even if they weren't actually made at the St. Vincent factory, they could still use the same "recipe"...

This may be completely irrelevant, but one of Sampras' racquets does break in this video...

http://youtube.com/watch?v=hXanTpQkx38

kenshireen
01-28-2008, 06:49 PM
If someone had a racket used it for several years.... Then he also had the same racket made at the same factory..same specs and never used it... Cut both apart.. put the cross sections.. handle, throat and head under a very powerful scope to see if there were indeed any Structural changes.. In the absece of any such evidence AND... having used the same racket for 15 years and then coming acorss the identical racket.. in unused form.... strung both at the same weight..same string, same machine... I could NOT tell the difference.

So therefore based upon my empirical study I conclude the the carbon-fibers in a tennis racket or epoxy of whatever do not breakdown or if they DO it is unrecognizable to the player

racquet_jedi
01-28-2008, 06:57 PM
If someone had a racket used it for several years.... Then he also had the same racket made at the same factory..same specs and never used it... Cut both apart.. put the cross sections.. handle, throat and head under a very powerful scope to see if there were indeed any Structural changes.. In the absece of any such evidence AND... having used the same racket for 15 years and then coming acorss the identical racket.. in unused form.... strung both at the same weight..same string, same machine... I could NOT tell the difference.

So therefore based upon my empirical study I conclude the the carbon-fibers in a tennis racket or epoxy of whatever do not breakdown or if they DO it is unrecognizable to the player

Though, it depends on the player, the pros seem to notice it, though, that is because they hit the ball so hard and that they've probably been using the same racquet model that they used their whole career so they know what's different about their racquet...

Bud
01-28-2008, 07:01 PM
Though, it depends on the player, the pros seem to notice it, though, that is because they hit the ball so hard and that they've probably been using the same racquet model that they used their whole career so they know what's different about their racquet...

I think many of the pros will say anything their sponsoring company wants them to say. They say racquets break down and go dead because they want to keep selling lots of racquets.

racquet_jedi
01-28-2008, 07:23 PM
I think many of the pros will say anything their sponsoring company wants them to say. They say racquets break down and go dead because they want to keep selling lots of racquets.

Think about it...

Pros play almost everyday and they hit the ball really hard, as shown when they hit over 70-100 MPH groundstrokes and 100+ MPH serves...

Most of us on here probably don't play as often or hit as hard as they do, so we don't need to have new racquets every month or anything, we probably don't even need them every 5-10 years...

If I was Pete Sampras in his touring days, and any of my racquets broke, I would sure contact Wilson to send me some more...

dacrymn
01-28-2008, 07:41 PM
To those who think racquets do not degrade over time:

So basically you're saying that the material (graphite) will last forever? And that, being the magical material that it is, it could take that constant abuse (from recreational and professional players), and NOT take ANY damage at all? Think about it. That doesn't even begin to make sense. Believe it or not, things degrade over time, regardless of any realistic circumstances.

If you want to argue that it wouldn't change the feel, that's fine too. However, you always have to take that comparison to the extreme. If that material (which, in the molecular level is a rigid substance. Look up "covalent network" bond) were to be twist and bend for so long, the resin and other forces holding the particles together will begin to break apart. Eventually you WILL feel the difference. However, in all fairness, no one's going to be using a racket for that long, so its all good.

Bud
01-28-2008, 07:49 PM
To those who think racquets do not degrade over time:

So basically you're saying that the material (graphite) will last forever? And that, being the magical material that it is, it could take that constant abuse (from recreational and professional players), and NOT take ANY damage at all? Think about it. That doesn't even begin to make sense. Believe it or not, things degrade over time, regardless of any realistic circumstances.

If you want to argue that it wouldn't change the feel, that's fine too. However, you always have to take that comparison to the extreme. If that material (which, in the molecular level is a rigid substance. Look up "covalent network" bond) were to be twist and bend for so long, the resin and other forces holding the particles together will begin to break apart. Eventually you WILL feel the difference. However, in all fairness, no one's going to be using a racket for that long, so its all good.

Everything degrades over time (according to our definition/perception of what degrading/disorder means/is). It's the nature of the universe. Things go from order to disorder... [K]arbon black included... :twisted:

The issue is whether racquets actually go 'dead'... i.e. can a player tell the difference between a new racquet and one that has been restrung, say... a thousand times and been hit with for 5000 hours.

Deuce
01-28-2008, 09:45 PM
The issue is whether racquets actually go 'dead'... i.e. can a player tell the difference between a new racquet and one that has been restrung, say... a thousand times and been hit with for 5000 hours.
I think the issue is even deeper than that.
If the racquet degrades, and the player can feel the difference over time, it does not necessarily mean that this is a negative occurrence.
I think that people are automatically assuming that when a raquet degrades, it's a bad thing.
But it is just as likely that the player will like the racquet more as it degrades.

kairosntx
01-28-2008, 10:05 PM
The OP likes his older racquets and I will agree that if they feel good to you and you play well with them, keep using them and even buy more of them in good used condition. I love my 25 year old racquets and still use them 2x/wk.

bad_call
01-29-2008, 04:32 AM
degrade? somewhat...then they get a new paint job and model name change. :mrgreen:

ckthegreek
01-29-2008, 04:48 AM
Surely, any company that specializes in racquet customisation should be able to measure fairly accurately the racquet's stiffness over time.

CAM178
01-29-2008, 04:51 AM
Yes, they do. That's why I'm switching racquets. The playing life in mine are done, and they have discontinued my model. 3 years is a long time for racquets, anyway. It's high time for some new sticks.

Mine lost their playability due to too many stringjobs and a ton of use. These racquets will not last forever.

Pusher
01-29-2008, 05:08 AM
Here's your proof...

"And if you string with a hybrid, all at the same tension, keep in mind that the crosses will be tighter than the mains since they’re shorter. Plus, during stringing, as the cross strings are pulled through the main strings they loosen the mains slightly. In the end, customizing your racquet may not be enough. Each time you hit a ball, you break racquet fibers. Though there may not be a visible crack in the frame, a racquet will eventually start to feel dead. Most pros go through 50 to 70 racquets a year. In his playing days, Andre Agassi used about 100 annually. If your racquet feels dead, or “soft,” you might need an upgrade."

http://tennis.com/yourgame/gear/general/general.aspx?id=96506

That statement is unfounded and in dispute. The X's are not necessarily tighter than the mains and many good stringers will say the opposite. Do racquet fibers crack or do they lose strength?-I don't think the author knows much about the subject and is simply parroting something he/she heard before. Of course the frame will lose some stiffness over time but how much?

I know a few fishing manufacturers that warranty graphite rods for 10 years or longer and they are under more stress than a tennis racquet. I suspect a tennis frame will hit well until it breaks.

kairosntx
01-29-2008, 06:14 AM
I suspect a tennis frame will hit well until it breaks.


I agree pusher...

not just fishing rods but think about all the products made with graphite, kevlar and other similar materials that last and are functional for much longer periods of time than frame manufacturers suggest.

TennezSport
01-29-2008, 07:09 AM
OK, it's a matter of simple physics. Anything that undergoes stress or shock will breakdown at the molecular level over time. Have you ever bent a thin piece of metal back and forth until it breaks??? If so, take a look at any slo-mo vids on youtube and you will see the racquet flexing at impact.

Now for the time part. For the average player out there the effects on racquets is not that noticible unless you are very good and play alot. Most players do not have the level of accuracy to stress the racquet enough to notice right away. Additionally, as most people play they become used to the more flexible feel of the racquet over time. It's only when they buy a new racquet/same model that they say, "Wow, this racquet does not feel the same".

Pro players string their racquets almost every day and hit very hard with a good deal of accuracy. This puts tremendous stress on the frame, so they will go through 60-100 frames a year(depending on player, style, string used, stringer and stringing machine used). When we get new frames in we put them on a Babolat RDC which measure flex among other things. We use this number as a reference number and then re-test during the year when we re-string. Depending on make, model and materials, and player, you can see the flex numbers rise as the racquet ages.

We have customers who have had their racquets for 10 years and still play with them. Is the racquet softer than when it was new, yes, but they can't tell the difference and they are still having fun. So go out there and play with your racquets as long as you are happy with them.

TennezSport :cool:

sureshs
01-29-2008, 07:35 AM
My racquet decays radioactively with a half-life of 1 day.

Pusher
01-29-2008, 09:37 AM
OK, it's a matter of simple physics. Anything that undergoes stress or shock will breakdown at the molecular level over time. Have you ever bent a thin piece of metal back and forth until it breaks??? If so, take a look at any slo-mo vids on youtube and you will see the racquet flexing at impact.

Now for the time part. For the average player out there the effects on racquets is not that noticible unless you are very good and play alot. Most players do not have the level of accuracy to stress the racquet enough to notice right away. Additionally, as most people play they become used to the more flexible feel of the racquet over time. It's only when they buy a new racquet/same model that they say, "Wow, this racquet does not feel the same".

Pro players string their racquets almost every day and hit very hard with a good deal of accuracy. This puts tremendous stress on the frame, so they will go through 60-100 frames a year(depending on player, style, string used, stringer and stringing machine used). When we get new frames in we put them on a Babolat RDC which measure flex among other things. We use this number as a reference number and then re-test during the year when we re-string. Depending on make, model and materials, and player, you can see the flex numbers rise as the racquet ages.

We have customers who have had their racquets for 10 years and still play with them. Is the racquet softer than when it was new, yes, but they can't tell the difference and they are still having fun. So go out there and play with your racquets as long as you are happy with them.

TennezSport :cool:

I have noticed that when a frame starts to become too flexible it gives warning signals. Usually I see a small, apparent paint crack, just below the bottom of the stringbed where it attaches to the handle. That crack will eventually lead to a break. Flexible frames seem to reach that point quicker than more stiffer frames. Until I see that warning sign I think the frame is in good shape.

For example: On the very flexible Nblade I will see it begin to crack in about 2 months-for the stiffer N6.1 I will see it in about 4 months.

PimpMyGame
01-29-2008, 09:50 AM
My racquet decays radioactively with a half-life of 1 day.

ha ha do you have to wear a lead suit and diver's helmet when you play?!

Chace
01-29-2008, 10:05 AM
I remember reading something about this in Tennis magazine. Sorry , but I don't remember which issue. I think it was in 2006 or early 2007. I don't remember all the details of the article but the one thing that sticks out in my mind is that Tennis Mag said that the average life of a racket is 4 years. They said the racket would still be playable but you would be able to tell a difference in the playability due to the breakdown of the materials.

sureshs
01-29-2008, 12:28 PM
ha ha do you have to wear a lead suit and diver's helmet when you play?!

Not any more since I am left with playing with the one remaining NCoded nanoparticle

dacrymn
01-29-2008, 12:54 PM
I think the issue is even deeper than that.
If the racquet degrades, and the player can feel the difference over time, it does not necessarily mean that this is a negative occurrence.
I think that people are automatically assuming that when a raquet degrades, it's a bad thing.
But it is just as likely that the player will like the racquet more as it degrades.

Very true.

Generally, however, that doesn't happen, at least in my experience. There's also that annoying mental side to it as well. Ever heard someone say, "why can't I hit those shots anymore? I used to be able to"? Given the average's person's incapacity to admit any fault, they'll begin to look to their racquet, and then the blame comes.

People who really care that much would be those who spend months looking for the "perfect" racquet anyways, so any deviation from when then first tried it is, apparently, not good enough for them. Someone who didn't, of course, probably won't notice.

So while someone could just as well like a "broken-in" racquet, sometimes something else just gets in the way.

Bud
01-29-2008, 01:34 PM
I remember reading something about this in Tennis magazine. Sorry , but I don't remember which issue. I think it was in 2006 or early 2007. I don't remember all the details of the article but the one thing that sticks out in my mind is that Tennis Mag said that the average life of a racket is 4 years. They said the racket would still be playable but you would be able to tell a difference in the playability due to the breakdown of the materials.

And... Tennis magazine is supported by advertisers who make tennis racquets... Like HEAD, Wilson, Dunlop, etc... who buy the advertising space within the magazine to show their racquets... that keeps the magazine in business.

netman
01-29-2008, 01:39 PM
No. However physical skills do degrade over time.

Yes I could hit ripping forehands with a 13 oz. racquet when I was 20. No, I can not hit ripping forehands with the same 13 oz racquet at 45. Guess the racquet fibers have broken down. :)

-k-

bad_call
01-29-2008, 04:07 PM
No. However physical skills do degrade over time.

Yes I could hit ripping forehands with a 13 oz. racquet when I was 20. No, I can not hit ripping forehands with the same 13 oz racquet at 45. Guess the racquet fibers have broken down. :)

-k-

well said.

zhanny
01-29-2008, 04:10 PM
theres an article on tennis magazine saying the tennis racquet gets weak everytime you hit a ball
i think thats pretty bogus

Ultra2HolyGrail
01-29-2008, 04:20 PM
I dont think anyone can tell when the racquet goes dead. I dont think a racquet can go dead and not be damaged.. I could be wrong. But think you need a noticeable crack or just before the racquet breaks to be able to tell any difference..

dacrymn
01-29-2008, 04:27 PM
theres an article on tennis magazine saying the tennis racquet gets weak everytime you hit a ball
i think thats pretty bogus

Hmmm, well that needs to be rephrased. "Weak" is vague.

Graphite fibers do, in fact, break every time you hit the ball, especially on a framed shot. Hits in the sweetspot minimize this.

The racquet does not, however, get "weak." Theoretically yes, it does get weaker, but it is by no means weak.