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bruno hau
10-20-2007, 12:46 PM
I was at *********'s the other day and saw the stringing lady string 2 mains at a time (to save time, I guess). She said that was the way they (*********'s) taught her to string. But she also side she does NOT string 2 crosses at a time.

Is stringing 2 mains at a time OK to save a little time? Wouldn't the non-pulling main string not be as tight as the pulling main string?

TennisandMusic
10-20-2007, 12:58 PM
I was at *********'s the other day and saw the stringing lady string 2 mains at a time (to save time, I guess). She said that was the way they (*********'s) taught her to string. But she also side she does NOT string 2 crosses at a time.

Is stringing 2 mains at a time OK to save a little time? Wouldn't the non-pulling main string not be as tight as the pulling main string?

No I don't think that is ok at all. And saving time on the mains? They should take you all of five minutes if you're focused...

kingdaddy41788
10-20-2007, 01:00 PM
I was at *********'s the other day and saw the stringing lady string 2 mains at a time (to save time, I guess). She said that was the way they (*********'s) taught her to string. But she also side she does NOT string 2 crosses at a time.

Is stringing 2 mains at a time OK to save a little time? Wouldn't the non-pulling main string not be as tight as the pulling main string?

It's not ok. Don't do it. Don't let someone who does it string your racquet. What store were you at?

mpenders
10-20-2007, 01:08 PM
Generally, I would agree in saying no to pulling two mains at once on a standard frame. That, and it's time to find another stringer.

However, there are several racquetball frames that REQUIRE you to pull two mains at once. Head, Eforce, Wilson, Ektelon each have frames that require this.

So...make sure you undestand what the stringer was working on before judging too harshly.

shojun25
10-20-2007, 02:04 PM
I think he's referring to Golf smith.

And no, do not do that. The stringer will just give an inconsistent tension if you pull 2 mains at once.

mpenders
10-20-2007, 03:15 PM
I was guessing Oshman's (based on the " 's ")

nickb
10-20-2007, 03:18 PM
Dont do it....it wont save much time....the stringbed will be inconsistent.

gjoc
10-20-2007, 03:24 PM
I was guessing Oshman's (based on the " 's ")

Nine letters before the “ ’s ” though.

YULitle
10-20-2007, 05:02 PM
It's not ok. Don't do it. Don't let someone who does it string your racquet. What store were you at?

Enough said...

tbini87
10-20-2007, 05:41 PM
don't do it, don't let anyone who does it string your sticks. learn the right way and do it everytime to get consistent results.

dancraig
10-20-2007, 05:47 PM
I think a lot of stringers double and triple pull to save time and effort. I heard that the pre-strung racquets have all the mains pulled with one or two pulls. I heard they have one lady insert the string and another pulls the tension. Here are some of the machines used in those racquet factories.

http://www.eagnas.com/lilylee/racfactor.html

I had an old time stringer advise me to just add a couple of pounds to the requested tension to make up for the friction of double pulling everything. He said, "they can't tell any difference".
I've got a feeling we would be surprised at the number of respected stringers who do this all the time. Time is money, I guess.
I never do it.

dancraig
10-20-2007, 08:32 PM
I would like to take two identical racquets and string one correctly and double and triple pull the heck out of the other one, after adding a couple of pounds of tension to the second. Then take them out and hit.
If we could get our normal stringing time down to 15 minutes, four frames per hour would be some pretty good money. (just kidding)

bruno hau
10-20-2007, 10:35 PM
It was at Golf Smith. She was definitely stringing a tennis racket. The machine is a Gamma constant pull electronic machine (modern floor model of course). I guess for a contant pull electronic machine stringing 2 mains at one time MIGHT be OK?

JohnP
10-21-2007, 01:56 AM
No, 2 mains at a time is not OK. But it happens way too much. Professional stringing done at clubs and stores are some of the biggest ripoffs, not only the amount charged, but the general sloppiness like doubling up on mains, etc.

rlee7777
10-21-2007, 06:16 AM
By pulling two or three mains at a time, it is impossible to achieve a consistent stringbed at a reference tension. This bad technique is why racquets fresh from a "retail stringer" play so bad initially. I was in retail doing racquet stringing many years ago. While I took pride in my work and was very careful, stringers in other stores took shortcuts and were proud about the quickness of their job. Our Ektelon machines were all calibrated from the same tech, but jobs from each branch store came out different [I]because of the person doing the stringing[I]. USRSA certification means nothing. I am a tennis player and I know what a poor job would do with the racquet and someone's game. These other "stringers" are looking to make $$ quickly.

Moral of this rant: KNOW who is stringing your racquet! Don't be impressed by their fancy machines.

samster
10-21-2007, 07:07 AM
That's why I string my own rackets. No one to blame when it comes out wrong.

dacrymn
10-21-2007, 10:10 AM
What do you mean two mains at once? You mean down and up, then tension? if you do it one way, how do you tighten with the tensioner in the way, not to mention the throat?

abenguyen
10-21-2007, 10:19 AM
What do you mean two mains at once? You mean down and up, then tension? if you do it one way, how do you tighten with the tensioner in the way, not to mention the throat?

it just means that you lace two mains and tension there. rather than lacing one main and tensioning clamp and then repeat for 2 strings, they are saying that this stringer laced 2 mains tensioned off that last one and clamp which is bad

Hooooon
10-21-2007, 10:30 AM
even tension should not be your concern here, although it is afftected. by pulling on a string that is wrapped around the grommet you risk snapping the string if it gets caught and guarantee weakening your frame, possibly breaking it if you string anywhere near the high end recommended tension (above rec. tension you are a moron for trying to pull 2). ta ta

dacrymn
10-21-2007, 11:53 AM
but what about the handle that knocks against the tension wheel? What about the throat that gets in the way?

YULitle
10-21-2007, 01:16 PM
It should NEVER be done unless it is absolutely necessary, ala some racketball rackets.

USRSA certification DOES mean something, just less than what it used to. The point of knowing who is stringing your rackets is by far the best. Watch them string your racket. Ask questions. If any of the answers involve words like "shortcut" or "to save time", be suspicious.

Not all USRSA stringers are bad, but some are. I've heard of MRTs using this very same method to save time. It's sad, but true. However, if you cannot spend the time with the stringer that is necessary, either don't have it strung, or leave it with someone who is certified. A stranger who isn't certified is a bigger risk than one who is IMO.

User Name
10-21-2007, 01:42 PM
not ok.....

gjoc
10-21-2007, 03:10 PM
A stranger who isn't certified is a bigger risk than one who is IMO.

Iíd certainly agree with that.

To me, USRSA certification doesnít mean they donít do it wrong, it just means they supposedly know better.

lilxjohnyy
10-21-2007, 03:19 PM
i was just wondering if this also applied to crosses..

gjoc
10-21-2007, 04:03 PM
i was just wondering if this also applied to crosses..

Yes, absolutely.

Itís actually even more important to do one at a time with the crosses because of the friction/drag/resistance from weaving through the already-tensioned mains.

jasoncho92
10-21-2007, 04:17 PM
From common sense, i can say its a lot worse with poly than a multifilament or natural gut because of the coil memory which keeps poly from full evening the tension out on both mains. So if you have to do it with a softer string, go ahead but dont with poly. Also dont do it on crosses even if youre in a hurry

shojun25
10-21-2007, 05:11 PM
i was just wondering if this also applied to crosses..

This doesn't make sense... How can you even do it with cross stringing?

Mad iX
10-21-2007, 05:20 PM
Happens all the time. Stringers tend to get lazy when their lunch break is coming up.
I don't think it really saves much time at all. For me personally, most of the time I spend is on weaving the crosses anyway.
If you're stringing your own racket then you could try and see if you can feel the difference for yourself, but you will most likely get an inconsistent stringbed.

slice bh compliment
10-21-2007, 05:38 PM
Yes, there are crooked tennis professionals and stringers just like there are crooked lawyers, accoutnants and doctors.

I like pro shops, with guys who actually care about their products, services and reputations.

Places like golfschmidt, they are only good for a clothing or apparel sale, as far as I am concerned. Trusted with actual tennis equipment? Nah.

YULitle
10-21-2007, 05:41 PM
Happens all the time. Stringers tend to get lazy when their lunch break is coming up.
I don't think it really saves much time at all. For me personally, most of the time I spend is on weaving the crosses anyway.
If you're stringing your own racket then you could try and see if you can feel the difference for yourself, but you will most likely get an inconsistent stringbed.

You will get an inconsistent string bed. The question is whether or not you notice.

And just because you are stringing with a multifilament, doesn't mean the problem isn't there. The friction at the grommets when the string turns the corner is too great to insure that both mains are at the same reference tension. To prove this, if you have a linear tension head, pull both ways, one on one side of the mains, one on the other. The cummulative amount of string you pull through the grommets by pulling two at a time will be less than both separately. This directly relates to the actual tension on the mains.

Also, as it was stated. Doing this on crosses is WORSE. Because you have added the friction of the crosses against the mains to the friction of turning that corner. This is always bad. I can't see it saving time anyhow. Pulling two crosses at one time guarantees that you will be weaving a hard weave atleast once. The time saved from weaving one ahead is lost at the "benefit" of the time saved from pulling half the time. I would speculate that it doesn't balance out in the two-at-a-time's favor.

The bottom line, as I've stated before, is only do it when you have no other choice (like some racketball rackets.)

YULitle
10-21-2007, 05:44 PM
Yes, there are crooked tennis professionals and stringers just like there are crooked lawyers, accoutnants and doctors.

I like pro shops, with guys who actually care about their products, services and reputations.

Places like golfschmidt, they are only good for a clothing or apparel sale, as far as I am concerned. Trusted with actual tennis equipment? Nah.

Not ALL of them are bad. I hear they are better on the West Coast and near New York, but for the most part, I'm afraid, you are right.

Again, the better your relationship with your stringer and the more questions you ask, the safer you and your racket are from mis-treatment.

Masamusou
10-21-2007, 05:51 PM
Yes, there are crooked tennis professionals and stringers just like there are crooked lawyers, accoutnants and doctors.

I like pro shops, with guys who actually care about their products, services and reputations.

Places like golfschmidt, they are only good for a clothing or apparel sale, as far as I am concerned. Trusted with actual tennis equipment? Nah.

And another perfect example of a broad generalization that makes you sound completely ignorant. I know for a fact that some of the locations have MRTs, one such MRT in the Dallas area for example posts on these boards sometimes and has strung pro tournaments for a while. Another MRT in the Denver area uses his personal Star 5 instead of the substandard Neos 1000 that is provided. No national chain is going to have great stringers at all locations, but to make the comment that *none* of them do is entirely ridiculous and only serves to show your ignorance.

Netbudda
10-21-2007, 05:55 PM
Funny, I saw a pro of a well respected tennis club here in Davidson, NC pulling two crosses until the racquet was done ( I don't know about the mains, they were already done before I started watching ). I asked him if it was alright to do so and he said it was. It got me thinking really hard about how much they really care about the customers, especially if the racquet owner is just a senior guy who just plays recreational tennis.

chrisplchs
10-21-2007, 06:04 PM
There are some racquets that you have to double pull the mains (i.e. Prince Ring) which sux to do.

But generally, for most racquets, double pulling is crime punishable by a punch in the crouch

IanRichardson
10-21-2007, 06:13 PM
This is why it is important to find a good reputable stringer who you can establish a relationship with, and trust. I personally would never have my racquet strung by a large retail store, eg. (Sprts Auth) because USUALLY (not all the time) the person stringing knows little to nothing about tennis. That is at least what i have found to be true. The best thing to do is get a stringing machine and do it yourself, it isnt hard and it really isnt that time consuming. If you insist on having someone else do the job for you then find a shop which has someone who is certified, or someone who really knows what they are doing. Here in winston-salem NC, the best tennis shop is ran buy a guy who is not USRA, but who has been stringing (and stringing correctly) for about 30 years. On the other hand, in High Point, NC there is a tennis center with a few USRA guys that I would not trust my sticks to. The point of what i said is, find someone that knows what they are doing, and above all you trust, and let them do the work.

slice bh compliment
10-21-2007, 07:30 PM
And another perfect example of a broad generalization that makes you sound completely ignorant. I know for a fact that some of the locations have MRTs, one such MRT in the Dallas area for example posts on these boards sometimes and has strung pro tournaments for a while. Another MRT in the Denver area uses his personal Star 5 instead of the substandard Neos 1000 that is provided. No national chain is going to have great stringers at all locations, but to make the comment that *none* of them do is entirely ridiculous and only serves to show your ignorance.


Very sorry you think I sound ignorant. Maybe I am ignorant.

Maybe you've got a bit of a temper...and a soft spot for some of the very good people associated with a certain chain. I do not know.

Obviously there are exceptions, man. But I would like to point out (from my experience as a player, a stringer, an MRT and a tester for both the USPTA and the USRSA) that...just because someone is an MRT does not mean they are always going to uphold that high standard after they pass that test. And it definitely does not mean that the MRT always holds his uncertified staff to that standard.

For the record, I never said that *NONE* of the people at GS string well. You used that word. I'm just saying that I trust stringers I know. Not just myself, but the pro shop guys I know. ANd I really trust a shop where I know ALL the stringers who might work on my frame are solid.
You just do not know who is allowed on the stringing machine at certain places.

SO sorry I made you so angry. My apologies. Please do forgive me for not being very clear the first time.

GoochMoney
10-22-2007, 08:07 AM
That is crazy...find another stringer.

Yesterday, after a match I got talking to my opponent that was looking at purchasing a stringing machine. He was hesitating because the guy they use at the "AUTHORITY" is really good and he picked up a bunch of strings on clearance there. He has no stringing experience so I advised him to pay attention to the mounting because you can really damage a racquet, and maybe even break the frame. He then tells me that this has happened to him at the "AUTHORITY" and they told him they would not do anything because he bought the racquet on clearance -- from them. Crazy!

Lefty5
10-22-2007, 08:53 AM
ok, i admit it, i even pull 2 strings at once when i string my own rackets. I can't tell much off a diff. My question is this...over time, does the inconsistency in the string bed even out? How many sets do you think it takes until all the strings are the same?

knasty131
10-22-2007, 09:45 AM
I also string my rackets by pulling 2 mains and 2 crosses at once...I have done both ways and don't feel a difference...and I am very sensitive on how my strings feel so I think I would notice an "inconsistent string bed"...

I am going to email Wilson, Babolat and several other racket companies and ask if this voids warranty just for my own information...

But as far as this being a practice that is "unacceptable", I think it was started by someone who thought that it was bad and voiced his/her opinion and it has become generally accepted amongst everyone...

My doubles partner used to think that stringing 2 at once was bad and saw me do it and I just flat told him that I don't notice any difference and now he does it and says he doesn't either...

I'm not saying go out and do this, but I have only used this method on all of my main playing rackets (HPS 7.1, HPS 6.1, nBlade, & Babolat PDR) and nothing bad has ever come from it...

-Kevin

rlee7777
10-22-2007, 10:35 AM
I also string my rackets by pulling 2 mains and 2 crosses at once...I have done both ways and don't feel a difference...and I am very sensitive on how my strings feel so I think I would notice an "inconsistent string bed"...

I am going to email Wilson, Babolat and several other racket companies and ask if this voids warranty just for my own information...

But as far as this being a practice that is "unacceptable", I think it was started by someone who thought that it was bad and voiced his/her opinion and it has become generally accepted amongst everyone...

My doubles partner used to think that stringing 2 at once was bad and saw me do it and I just flat told him that I don't notice any difference and now he does it and says he doesn't either...

I'm not saying go out and do this, but I have only used this method on all of my main playing rackets (HPS 7.1, HPS 6.1, nBlade, & Babolat PDR) and nothing bad has ever come from it...

-Kevin

Of course it will "work"...the tension will not be consistent across the stringbed initially -- after some time hitting, it will even out, but at a lower unpredictable tension that is not "reference". In other words, stringing this way at "60 lbs" for example, will NOT be a true "60 lbs" -- it will stabilize at a lower tension that is unpredictable because of the varying degrees of grommet friction.

If you are stringing for yourself, fine. But this is not a good method to assure a reliably consistent, accurate stringing job.

rorschack
10-22-2007, 10:55 AM
This is really really bad! And I'll tell you why. I decided to measure the actual tension of my drop weight stringer with the clutch/rachet by using a fish scale which is a very common method. I have a fixed clamp system by the way.

I tested it with the racquet mounted and simulating how I would pull the first main string with a starting clamp, clamping the string on an adjacent hole on the inside of the racquet. When there's no friction at all like pulling with the head of the racquet pointing toward the string gripper, the tension was dead on.

Now, when tensioning the opposite way, with the string bent under the frame, the tension was CONSISTENTLY 2-3 lbs lower! I tested and re-tested many times, and it's still 2-3 lbs lower. The friction resulted from the bend reduced the tension by 2-3 lbs!

I also tested the tension without the frame mounted, and the fish scale showed that the tension was dead on, meaning that my drop weight stringer is good.

Lesson learned was that any kind of friction will result in significant tension loss. duh! I can't imagine how much tension you are losing by pulling 2 mains at a time, let alone pulling two crosses with the mains already in.

As for cross, I used to reduce about 2lbs lower than the main, thinking that the cross is shorter, but after seeing how much friction can reduce tension, I am stringing it at the same as the main from now on!

courtrage
10-22-2007, 01:38 PM
i dont think anyone can tell the diff between 2-3 lbs...i also think i heard about a study that found most people couldnt tell between 5lbs difference...who knows...

i've double pulled mains on my frames for 7 years and been stringing for 10 or 11 years total...i only really do my own frames and sometimes a friends and never broken any strings or frames on the machine and friends never complained about tension... my machine has a crank, not a weight...

slice bh compliment
10-22-2007, 06:58 PM
2 or three lbs, huh? I believe it, and I think that is significant. In fact I'm impressed that it was not 5 lbs lost.

I suppose if you are perfectly consistent and always do it...and bump up your reference tension 2 or 3 lbs, you're cool. But I still think it is shoddy. Probably depends on the frame, the friction with the grommet strip, the type of string...those sorts of variables.

Wonder what the loss is on crosses if you pull two at a time?

Never mind. I'm not considering it. Ever. That's weak.

gjoc
10-22-2007, 07:23 PM
i dont think anyone can tell the diff between 2-3 lbs...i also think i heard about a study that found most people couldnt tell between 5lbs difference...who knows...


That was an interesting article, if youíre thinking of this one (http://www.racquetsportsindustry.com/articles/2005/02/outlook_2005_string.html).

Here is an excerpt:



Tension and Player Perceptiveness

Virtually all players assume that they can tell the difference between different tensions. Some claim to be able to identify a difference of a pound or two. Tests have been performed (Professors Rod Cross and Rob Bower) that bring that claim into question. In a test of 41 advanced recreational players, only 11 (27 percent) could determine a difference of 11 pounds or less. In fact, 15 (37 percent) couldn't correctly identify the difference even when the tension between two racquets varied by 22 pounds.

Using earplugs to dampen auditory clues lowered the success rates even more. Players were only allowed four hits with each racquet, so the only data the player was interpreting was feel, not an accumulated history of location of ball placement that could be used to deduce string tension. Some players said that they noticed a difference, but then incorrectly chose which racquet had a higher tension.



Note that when they say that the players couldnít tell the relative tensions, that was based on literally just the feel of the racquets hitting the balls.

They didnít let the players hit enough times to get any feedback on where the balls were going on the court, and it doesnít mean that the players wouldnít be able to tell/notice the difference in tension if they were to actually play tennis with the different racquets.

slice bh compliment
10-22-2007, 07:28 PM
That test is awesome. But a little contrived don't you think? Four shots?

Just two weeks ago, I got two identical sticks strung up with the same stuff. One at 60/56, the other at 58/54. Unlabeled. I could definitely tell the difference. By sound, and after just about four or five shots...it was fairly obvious.
And I consider myself not all that sensitive.

kingdaddy41788
10-22-2007, 07:31 PM
That was an interesting article, if youíre thinking of this one (http://www.racquetsportsindustry.com/articles/2005/02/outlook_2005_string.html).

Here is an excerpt:



Note that when they say that the players couldnít tell the relative tensions, that was based on literally just the feel of the racquets hitting the balls.

They didnít let the players hit enough times to get any feedback on where the balls were going on the court, and it doesnít mean that the players wouldnít be able to tell/notice the difference in tension if they were to actually play tennis with the different racquets.

Four shots though? Come on. You'd have to give them ten at least. Especially if they weren't warmed up.

gjoc
10-22-2007, 07:41 PM
That test is awesome. But a little contrived don't you think? Four shots?

Yeah, Iím with you.

I think it was an interesting article/study, in an intellectual curiosity kind of way, but I donít think it had any practical significance.

You know, itís like how itís hard to tell how a racquet feels just by bouncing a ball on it, but even small differences are easily noticeable as soon as you start to play with it on a court.

YULitle
10-22-2007, 07:41 PM
In "The Physics and Technology of Tennis," they site a study that said that over 50% of recreational tennis players can't tell a 15 lbs. difference. And, that when 18 professional satellite players were tested, 11 of them couldn't tell an 11 lbs. difference.

This shouldn't take away from my previous statements of how wrong this practice is. Unless you do this for only your rackets, you should never pull two at a time.

This isn't something that is rooted in tradition. Stringers don't say not to do it simply because someone told them not to, most of the time. Anyone with a little knowledge of physics can see quite clearly that the tension on the first string is not the same as the first. This creates an inconsistent string bed. There is no arguing this point. It is fact. Aruge all you want that you can't tell the difference. I believe that you can't.

gjoc
10-22-2007, 07:43 PM
Four shots though? Come on. You'd have to give them ten at least. Especially if they weren't warmed up.

LOL, You must warm up a lot faster then me! ;)

kingdaddy41788
10-22-2007, 07:45 PM
LOL, You must warm up a lot faster then me! ;)

Haha I wasn't implying that they'd be fully warm. But if they were even going to have a chance of noticing a difference, they'd need more than 4 shots.

gjoc
10-22-2007, 07:49 PM
In "The Physics and Technology of Tennis," they site a study that said that over 50% of recreational tennis players can't tell a 15 lbs. difference. And, that when 18 professional satellite players were tested, 11 of them couldn't tell an 11 lbs. difference.

You realize itís the same author, right?

So itís not too surprising if it says the same thing. ;)


About the Author
Crawford Lindsey (http://www.racquetsportsindustry.com/images/author-crawford_lindsey.jpg)is editor-in-chief of RSI magazine. He is co-author of The Physics and Technology of Tennis (http://www.usrsa.com/store/ptot.html) and Technical Tennis (http://www.usrsa.com/store/technical.html)

gjoc
10-22-2007, 07:52 PM
Haha I wasn't implying that they'd be fully warm. But if they were even going to have a chance of noticing a difference, they'd need more than 4 shots.

Haha--six shots and youíre good to go! Nothing wrong with that!

LPShanet
10-23-2007, 01:20 PM
This is really really bad! And I'll tell you why. I decided to measure the actual tension of my drop weight stringer with the clutch/rachet by using a fish scale which is a very common method. I have a fixed clamp system by the way.

I tested it with the racquet mounted and simulating how I would pull the first main string with a starting clamp, clamping the string on an adjacent hole on the inside of the racquet. When there's no friction at all like pulling with the head of the racquet pointing toward the string gripper, the tension was dead on.

Now, when tensioning the opposite way, with the string bent under the frame, the tension was CONSISTENTLY 2-3 lbs lower! I tested and re-tested many times, and it's still 2-3 lbs lower. The friction resulted from the bend reduced the tension by 2-3 lbs!

I also tested the tension without the frame mounted, and the fish scale showed that the tension was dead on, meaning that my drop weight stringer is good.

Lesson learned was that any kind of friction will result in significant tension loss. duh! I can't imagine how much tension you are losing by pulling 2 mains at a time, let alone pulling two crosses with the mains already in.

As for cross, I used to reduce about 2lbs lower than the main, thinking that the cross is shorter, but after seeing how much friction can reduce tension, I am stringing it at the same as the main from now on!

The other thing no one has mentioned is the uneven stress put on the racquet during stringing. Pulling tension from the same side all the time does have a cumulative effect on the frame. Although frames are usually well made enough to withstand this with no visually apparent damage, it breaks down the graphite faster by stressing one side repeatedly, and by having the frame pull against the mounting system in the same direction all the time. Not a good thing, even if the player can't feel it.

SW Stringer
10-23-2007, 01:24 PM
Interesting topic. Here's some more food for thought. In that same book "The Physics and Technology of Tennis" a racquet was instrumented with strain gauges in the first main (1RM) and the tenth cross (10X) so that precise measurements of tension could be made as the racquet was strung. When the tenth cross was put in at a reference tension of 70 lbs, the strain gauge at the opposite side of the frame registered just under 60 lbs. The tension loss due to friction with the mains was just over 10 lbs. Presumably the next cross 11X will also lose 10 lbs but the profile will be reversed, and so on. In the exact center of the crosses the tension would be 65, near the rim it would be 70, 60, 70, 60 , and halfway between the frame and center it would be 67.5, 62.5, 67.5, 62.5 etc., the average of all the spots is 65 lbs. Depending on the pattern density of the racquet the ball can contact up to 6 mains and 6 crosses when flattenned out on the string bed. So just by following Generally Accepted Stringing Practices (GASP) adjacent crosses near the rim can have a ten pound differential. This begs the question, if you didn't already know this from reading the book, or had perceived this just from feel - then what difference would it make if adjacent mains had a mere 2 or 3 pound differential - it seems as if it would just average out over the number of strings that the ball contacts. Probably imperceptible to most humans. Hmmmmmmmm - think about it!!! :p

SW Stringer
10-23-2007, 01:41 PM
I would like to take two identical racquets and string one correctly and double and triple pull the heck out of the other one, after adding a couple of pounds of tension to the second. Then take them out and hit.
If we could get our normal stringing time down to 15 minutes, four frames per hour would be some pretty good money. (just kidding)

I don't think many people could tell a difference in a double blind test. With the basic assumption of two pounds loss in a double pull and a reference tension of 60 pounds, by just adding one pound to the double pull case, the average mains tension would still be 60 pounds (59 + 61 = 120, 120 /2 = 60). The same 60 as the ref tension on a single pull mains string job. If you assume 3 pounds loss, then add 1.5 pounds to the double pull case. I'm not advocating varying from GASP, but really who could tell (besides the stringer who has to live with his conscience)? :p

Masamusou
10-23-2007, 01:53 PM
I don't think many people could tell a difference in a double blind test. With the basic assumption of two pounds loss in a double pull and a reference tension of 60 pounds, by just adding one pound to the double pull case, the average mains tension would still be 60 pounds (59 + 61 = 120, 120 /2 = 60). The same 60 as the ref tension on a single pull mains string job. If you assume 3 pounds loss, then add 1.5 pounds to the double pull case. I'm not advocating varying from GASP, but really who could tell (besides the stringer who has to live with his conscience)? :p

In no way am I agreeing with this former customer, but here's a small anecdote about this debate. A guy that used to come to the store I work at always had another individual string his frames for about a year. This other employee double pulled on the mains, strung bottom to top on everything, and tightened the knots with the tensioner. It would regularly take him an hour to 2 hours to finally finish the job. So after much trial and error this former customer and the former employee had decided that 61 pounds was the correct tension. The employee eventually left, leaving me to do the stringing. After another series of trial and error and many problems with the individual, it was finally established that even at a tension of 55 pounds, the final product was too tight in comparison. After some arguments because of the "customer's" claims and the impossibility of matching a freshly strung frame to a frame that was strung 4 months ago, it finally became obvious to corporate that the individual would never be happy unless he received free products forever. This is obviously why he is a former customer. Could he actually tell the difference? Hard to say, but DT measurements on the previous frame double pulled at 61 matched my job at 55. This is one isolated example obviously, but it does show a difference.

LPShanet
10-23-2007, 04:07 PM
Interesting topic. Here's some more food for thought. In that same book "The Physics and Technology of Tennis" a racquet was instrumented with strain gauges in the first main (1RM) and the tenth cross (10X) so that precise measurements of tension could be made as the racquet was strung. When the tenth cross was put in at a reference tension of 70 lbs, the strain gauge at the opposite side of the frame registered just under 60 lbs. The tension loss due to friction with the mains was just over 10 lbs. Presumably the next cross 11X will also lose 10 lbs but the profile will be reversed, and so on. In the exact center of the crosses the tension would be 65, near the rim it would be 70, 60, 70, 60 , and halfway between the frame and center it would be 67.5, 62.5, 67.5, 62.5 etc., the average of all the spots is 65 lbs. Depending on the pattern density of the racquet the ball can contact up to 6 mains and 6 crosses when flattenned out on the string bed. So just by following Generally Accepted Stringing Practices (GASP) adjacent crosses near the rim can have a ten pound differential. This begs the question, if you didn't already know this from reading the book, or had perceived this just from feel - then what difference would it make if adjacent mains had a mere 2 or 3 pound differential - it seems as if it would just average out over the number of strings that the ball contacts. Probably imperceptible to most humans. Hmmmmmmmm - think about it!!! :p

Interesting point. But for the record, I brought up lopsided stresses not for the playing issues, but for how it impacts the racquet's integrity in the long term. That's also why many companies tell you not to do it (although there's no practical way they could tell after the fact).

SW Stringer
10-23-2007, 09:26 PM
Interesting point. But for the record, I brought up lopsided stresses not for the playing issues, but for how it impacts the racquet's integrity in the long term. That's also why many companies tell you not to do it (although there's no practical way they could tell after the fact).

I don't pretend to be a frame designer, so I won't say that double pulling doesn't create lopsided stresses in the frame, but, in the book "Physics and Technology of Tennis" they also measured the dynamic stresses created on the strings when striking the ball - and the tensions of the strings directly impacted by the ball DOUBLED - so strings that had 50 pounds of tension went to 100 pounds of tension each and every time the ball was hit. By deduction one may conclude that if the frame can take the lopsided stresses of playing where the tensions routinely double maybe hundreds of times in a match, then maybe 2 to 3 pounds of lopsided stress on the frame during stringing is well within the design limits imposed by the dynamics of ball impact.

OneHander
10-23-2007, 09:42 PM
I have been stringing my own rackets for 25 years and have always pulled two strings on the mains only. My rackets have never broken, cracked, or shown stress from stringing. In fact, I used my same rackets for the past 17 years until recently switching. I am a 5.5 player, played Division I tennis, played circuit tournaments and never thought about inconsistent stringbed tension. I am not saying that pulling two strings is correct, I am just giving my own experience based on some pretty competitive play. I used Prince graphite rackets (POG) and still do today. I have a drop weight stringer and string my rackets between 61-65 lbs.

rorschack
10-24-2007, 12:16 PM
I have been stringing my own rackets for 25 years and have always pulled two strings on the mains only. My rackets have never broken, cracked, or shown stress from stringing. In fact, I used my same rackets for the past 17 years until recently switching. I am a 5.5 player, played Division I tennis, played circuit tournaments and never thought about inconsistent stringbed tension. I am not saying that pulling two strings is correct, I am just giving my own experience based on some pretty competitive play. I used Prince graphite rackets (POG) and still do today. I have a drop weight stringer and string my rackets between 61-65 lbs.

It's probably because you got used to the way you string your racquets. Now have you tried giving your racquets to a friend with a nice stringing machine or to a legit proshop who would string at your regular tension? Maybe you can tell the difference.

courtrage
10-24-2007, 12:34 PM
LOL, You must warm up a lot faster then me! ;)

ha...i take the ball out of my pocket, drop it like i'm gonna hit it(but i dont) and i'm warm ;-) j/k use to do that with friends to warmup serves as a joke...i toss the ball then catch it and say "ready when you are" :-D

LPShanet
10-24-2007, 01:26 PM
I don't pretend to be a frame designer, so I won't say that double pulling doesn't create lopsided stresses in the frame, but, in the book "Physics and Technology of Tennis" they also measured the dynamic stresses created on the strings when striking the ball - and the tensions of the strings directly impacted by the ball DOUBLED - so strings that had 50 pounds of tension went to 100 pounds of tension each and every time the ball was hit. By deduction one may conclude that if the frame can take the lopsided stresses of playing where the tensions routinely double maybe hundreds of times in a match, then maybe 2 to 3 pounds of lopsided stress on the frame during stringing is well within the design limits imposed by the dynamics of ball impact.

Your logic is almost correct, but unfortunately, the extrapolation you made isn't. It's based on an incomplete knowledge of physics, and that's not how they apply here. The lab folks Crawford consulted for that book would support the following assertions. First, when the ball strikes a complete string bed, the 100 pounds of "tension" you spoke of is distributed over the entire stringbed, which is at that point complete. At the same time, a completed racquet is actually given increased strength in all directions by the strings themselves. In effect, they hold the racquet together. However, when you pull a single string during stringing, the bulk of the force of that string is placed on the frame at the location of the holes being used, and therefore on a particular area of the racquet. Think of lying on a bed of nails versus one nail. Which one punctures the skin? While it's in the process of being strung, that frame is much more vulnerable, since the strings aren't doing an even job (or sometimes any of the job) of holding the frame together in shape. If you measure this as stress per square area, the two examples aren't even close. The stress of the single string on the incomplete frame is many tens of times greater. (This also relates to why many racquets should never have their crosses done from the throat up...too much pressure on the naked hoop.)

Secondly, the ball force is placed perpedicular to the frame, which it is built for. When stringing, the stress goes parallel to the frame, which is the direction in which the frame is weakest. (Think about how frames break on a machine versus how they occasionally crack during play. The two types of break are very different.) So when I talk about always pulling in the same direction (which places the stress on the opposite side of the hoop and IS lopsided) at very high localized stresses, versus the completely evenly distributed (NOT lopsided) stress of hitting a ball, the two aren't comparable at all.

Finally, since we know that over time, the stress of hitting the ball does break down any frame material (which is why they eventually go "soft", "flat" or "mushy" over time and use), we can then apply this same knowledge to the fact that placing the much greater stress of stringing to one side of the hoop much more than the other will slowly break down the frame much more on one side than the other. The graphite matrix of the frame will have less integrity and on a microscopic level, the adhesive materials that hold the particles of graphite together will be pulled apart and/or delaminated internally. You won't see it, but it's happening.

Anyone who strung back in the days of the Prince Pro can picture what I'm talking about in terms of force, because as you strung that frame, it would clearly deform. If you strung it above 60-65 lbs (low for that frame) and did all the crosses from one side (double pulling), you'd end up with a lopsided snowshoe (not unlike the Snauwaert Ergonom in shape). When you do this with today's stronger, more resilient graphite frames, they don't stay deformed, but they do undergo the same stresses and the materials have to absorb them. (And to go back to the issue of the stress of hitting the tennis ball, those same people will remember that hitting with that racquet didn't change its shape even though the stringing did. Similarly, if you banged it on its edge, it would fold like a house of cards, but if you did the same face on, nothing would happen.)

I'm not saying double pulling will break your frame (it probably won't), but it will affect its integrity and playability over time, not to mention the uneven tension already discussed. And it's so easy to avoid: JUST STRING YOUR FRAMES PROPERLY, YOU LAZY SCHLUBS! :) How much extra time does it take? And there are no associated risks with doing it right. If you're just doing your own frames, no big deal...the risks are all on you. But if a professional stringer does this, it's just like a mechanic not really changing the oil every time you ask/pay him to. Your car might well be fine, and you might not notice your car break down that week, but it can't be good for the car over the long term, and it's wrong. And it's very easy to just do it right. If the double-pullers out there need to make themselves feel better by justifying what they're doing, that's fine, but don't use physics to incorrectly support what you're doing. The science disagrees.

OneHander
10-24-2007, 11:04 PM
It's probably because you got used to the way you string your racquets. Now have you tried giving your racquets to a friend with a nice stringing machine or to a legit proshop who would string at your regular tension? Maybe you can tell the difference.

I did do that just to gauge my own stringer against a reputable shop. I liked my string job better. At least I can be assured of the quality control when I string my racket, even if the way that I do it doesn't seem to be popular. I have also strung rackets for many people using the same technique and have never received a negative response. In fact, I was able to get as much repeat business as I wanted. Stringing was my hobby not my business.

However, in the interest of keeping an open mind and being open to new suggestions, I will try stringing my next few rackets by pulling the mains one string at a time. It will be interesting to see if I notice a difference.

LPShanet
10-25-2007, 06:36 AM
I did do that just to gauge my own stringer against a reputable shop. I liked my string job better. At least I can be assured of the quality control when I string my racket, even if the way that I do it doesn't seem to be popular. I have also strung rackets for many people using the same technique and have never received a negative response. In fact, I was able to get as much repeat business as I wanted. Stringing was my hobby not my business.

However, in the interest of keeping an open mind and being open to new suggestions, I will try stringing my next few rackets by pulling the mains one string at a time. It will be interesting to see if I notice a difference.

The fact that you liked yours "better" confirms that it was, in fact, different. So it does make a difference, as you can see. There would be a stronger case for not bothering with all the pulls if you couldn't feel the difference. Preferring your own work is a subjective thing, and may indicate that you really like your racquets strung looser than you thought:)

One of the several goals of good stringing is consistency. If all goes well, a specific reference tension should be the same as long as all the other factors are the same. So the fact that you produced different results means that you might want to find out why. If it's because of the machine that's one thing, if it's due to double pulling that's another, and if it's due to one of you having better technique in other areas, that's worth knowing also.

I totally agree with you, though, on the security of quality control when you do the work yourself. Considering the practices I've seen used at some of the stores I've been in, it's really amazing more people aren't complaining.

Great that you're open-minded about trying new techniques. It'll be interesting to hear if you feel any difference in your racquets when pulling all the strings. But even if you don't, there are still many compelling reasons for following the recommended procedure.

Pleepers
10-25-2007, 06:47 AM
Tension distributed over two strings instead of one is half the tension. So no, do not let anyone "double-pull" while stringing your racquet.

SW Stringer
10-25-2007, 11:57 AM
Your logic is almost correct, but unfortunately, the extrapolation you made isn't. It's based on an incomplete knowledge of physics, and that's not how they apply here. The lab folks Crawford consulted for that book would support the following assertions. First, when the ball strikes a complete string bed, the 100 pounds of "tension" you spoke of is distributed over the entire stringbed, which is at that point complete. At the same time, a completed racquet is actually given increased strength in all directions by the strings themselves. In effect, they hold the racquet together. However, when you pull a single string during stringing, the bulk of the force of that string is placed on the frame at the location of the holes being used, and therefore on a particular area of the racquet. Think of lying on a bed of nails versus one nail. Which one punctures the skin? While it's in the process of being strung, that frame is much more vulnerable, since the strings aren't doing an even job (or sometimes any of the job) of holding the frame together in shape. If you measure this as stress per square area, the two examples aren't even close. The stress of the single string on the incomplete frame is many tens of times greater. (This also relates to why many racquets should never have their crosses done from the throat up...too much pressure on the naked hoop.) . . . . .

I'm not so sure that Howard Brody nor Rod Cross would agree with your assertions. I don't understand how your bed of nails analogy applies to the string bed, but then again I thought my analogy was clear too. The nice thing about the book "P&Tof T" was their use of equatons of force, energy, and momentum conservation with examples that one could work through to understand the underlying principles. So could you explain in more detail how you came up with "If you measure this as stress per square area, the two examples aren't even close. The stress of the single string on the incomplete frame is many tens of times greater." Can you show an example, with actual data, or an experiment you've done, or read about that I could understand. Also, BTW the double pulling I was referring to was for main strings only as the topic of the thread suggests. Thanks. - SW

Bud
10-25-2007, 12:51 PM
Tension distributed over two strings instead of one is half the tension. So no, do not let anyone "double-pull" while stringing your racquet.

If I understand you correctly, you're stating that pulling 2 mains at a time with a reference tension of 60# will result in each main being 30 lbs? That's not correct.

I've tried both (pulling 1 main/pulling 2 mains) and notice no difference in the final analysis (I like my strings around 70#). I believe a large factor is the relative tension. There will be more tension loss if stringing the entire racquet at 50# as opposed to 70# since the 70# pull will overcome (or negate) more friction loss through the grommets/bends. So, I'd venture to say, if you're a two-main puller, the lower the tension the higher the error.

gjoc
10-25-2007, 02:12 PM
Tension distributed over two strings instead of one is half the tension. So no, do not let anyone "double-pull" while stringing your racquet.

If I understand you correctly, you're stating that pulling 2 mains at a time with a reference tension of 60# will result in each main being 30 lbs? That's not correct.

I think thereís some confusion over the term ďdouble-pull.Ē

Pleepers is thinking parallel (literally putting two strings, the left mains end and the right mains end, into the gripper and pulling at the same time) and Bud (and everyone else in this thread, I think) is thinking serial (running up and down two lengths before pulling that one end).

Iíve heard of stringers double-pulling in parallel to save time (i.e., pulling the left and right sides at the same time), and what Pleepers said about the tension in that case is correct, you would have to double the reference tension because each string would carry only half the load.

Parallel canít be nearly as bad as serial, but still wouldnít be preferred or considered proper compared to single-pulling, because the two strings couldnít stretch and/or draw through freely/independently, since theyíd be ďtiedĒ together (think if one string had way extra slack and never drew tight, and the other one stopped the tension head by carrying all of the 100 or 120 lbs--thatís an extreme example, but it illustrates the problem).

LPShanet
10-25-2007, 03:39 PM
I'm not so sure that Howard Brody nor Rod Cross would agree with your assertions. I don't understand how your bed of nails analogy applies to the string bed, but then again I thought my analogy was clear too. The nice thing about the book "P&Tof T" was their use of equatons of force, energy, and momentum conservation with examples that one could work through to understand the underlying principles. So could you explain in more detail how you came up with "If you measure this as stress per square area, the two examples aren't even close. The stress of the single string on the incomplete frame is many tens of times greater." Can you show an example, with actual data, or an experiment you've done, or read about that I could understand. Also, BTW the double pulling I was referring to was for main strings only as the topic of the thread suggests. Thanks. - SW

Actually, I think you'd find they would. Your analogy was clear, it was just oversimplified since different forces are at work in different directions and the two have nothing to do with each other in terms of this discussion. I've had this very discussion with may over at the USRSA, as well as some of Crawford's people, and the applied physics lab at The Johns Hopkins University (my alma mater). They are the ones who confirmed this, and you're welcome to ask the APL for any data you like.

But to help you out in this forum, when you apply tension to a string laterally (force in direction of the x axis), and the frame is not completely strung, the racquet wants to cave in, and there is nothing pulling in the opposite direction to neutralize this force. all the force is concentrated on the point at which the string loop meets the grommet hole. Let's call that 60 lbs of force directed at that exact point on the racquet, and it's in the direction in which the frame is symmetrical and not designed to flex much, so the frame can't absorb much of the force by flexing. When you hit a tennis ball, the force, which is still a constant, is applied in the direction of the z axis, so it's a totally different stress on the frame, and in this case it's also distributed across (depending on the string pattern density) 4-6 cross strings and 4-6 mains, so at least 8 points. So divide your "doubled force" by 8, just to start with. Then keep in mind that each of those eight strings has two contact points with the frame (one at each end of the string) so it's really 16 points that you're dividing by. Then add to that the fact that since all the strings are connected, you're actually getting some of the force absorbed by the other strings. Finally, add to that the fact that the frame is designed to flex against the force of the ball (which is directed perpendicular to the frame on the z axis) and you have the frame absorbing some of that force as well (which is also why more flexible frames seem to be less powerful). So not even close to the stress on any one part of the racquet of the string during stringing.

LPShanet
10-25-2007, 04:29 PM
I'm not so sure that Howard Brody nor Rod Cross would agree with your assertions. I don't understand how your bed of nails analogy applies to the string bed, but then again I thought my analogy was clear too. The nice thing about the book "P&Tof T" was their use of equatons of force, energy, and momentum conservation with examples that one could work through to understand the underlying principles. So could you explain in more detail how you came up with "If you measure this as stress per square area, the two examples aren't even close. The stress of the single string on the incomplete frame is many tens of times greater." Can you show an example, with actual data, or an experiment you've done, or read about that I could understand. Also, BTW the double pulling I was referring to was for main strings only as the topic of the thread suggests. Thanks. - SW

Just noticed your mention that we should be directing our attention at main strings primarily, since that was what the OP is about. The problems I described are definitely less important on the mains than crosses, but they do apply to mains somewhat, especially if you are doing all the pulling from the throat (putting the stress on the hoop end of the racquet) rather from than the head (with stress at the throat end, which is more sturdy). And somewhere in the thread various people have mentioned doing it on the crosses as well, so it's become a discussion on that as well.

SW Stringer
10-26-2007, 09:49 AM
Actually, I think you'd find they would. Your analogy was clear, it was just oversimplified since different forces are at work in different directions and the two have nothing to do with each other in terms of this discussion. I've had this very discussion with may over at the USRSA, as well as some of Crawford's people, and the applied physics lab at The Johns Hopkins University (my alma mater). They are the ones who confirmed this, and you're welcome to ask the APL for any data you like.

But to help you out in this forum, when you apply tension to a string laterally (force in direction of the x axis), and the frame is not completely strung, the racquet wants to cave in, and there is nothing pulling in the opposite direction to neutralize this force. all the force is concentrated on the point at which the string loop meets the grommet hole. Let's call that 60 lbs of force directed at that exact point on the racquet, and it's in the direction in which the frame is symmetrical and not designed to flex much, so the frame can't absorb much of the force by flexing. When you hit a tennis ball, the force, which is still a constant, is applied in the direction of the z axis, so it's a totally different stress on the frame, and in this case it's also distributed across (depending on the string pattern density) 4-6 cross strings and 4-6 mains, so at least 8 points. So divide your "doubled force" by 8, just to start with. Then keep in mind that each of those eight strings has two contact points with the frame (one at each end of the string) so it's really 16 points that you're dividing by. Then add to that the fact that since all the strings are connected, you're actually getting some of the force absorbed by the other strings. Finally, add to that the fact that the frame is designed to flex against the force of the ball (which is directed perpendicular to the frame on the z axis) and you have the frame absorbing some of that force as well (which is also why more flexible frames seem to be less powerful). So not even close to the stress on any one part of the racquet of the string during stringing.

Excellent suggestion in the first paragraph. Can you give me a contact at the APL and/or with Crawford's people. Before I contact them for an informative discussion on frame loading and static vs. dynamic forces, which chapters of "The Physics and Technology of Tennis" should I brush up on to get the most out of the conversation. Thanks. - SW

LPShanet
10-26-2007, 11:37 AM
Excellent suggestion in the first paragraph. Can you give me a contact at the APL and/or with Crawford's people. Before I contact them for an informative discussion on frame loading and static vs. dynamic forces, which chapters of "The Physics and Technology of Tennis" should I brush up on to get the most out of the conversation. Thanks. - SW

You can reach the APL at (443) 778-5000. The person who did the most playing with frame stresses was Dinh Nguyen, who was also on the school's tennis team prior to being with APL. Not sure if he's still there or at one of Cal's campuses now, since the tests were done over 10 years ago.

There are several chapters you're welcome to take a look at in "The Physics and Technology of Tennis". But I suspect you're already familiar with the book from what you've said. You seem to like it a lot as a reference, but your insistence on using this as your only reference and trying to apply its principles where they aren't relevant is also part of the reason you're not getting what I'm saying. That very informative and excellent book deals primarily with the physics of the racquet and string plane with respect to hitting a tennis ball. It doesn't deal with the long term effects of impacts on the frame itself. There also isn't anything in it about the stresses on the frame during stringing. Still, if you insist on re-studying what you already know, the areas to again take a look at are: Chapter 8 deals with racquet vibration theory, but also has a few mentions of frame bending and racquet motion during impact, and briefly hits on individual impacts on a racquet or planar structure. However, it doesn't apply physics to the materials impact over time on the frame itself. There are a few interesting things in Chapter 9 as well, talking about shock and impact in principle, but again, not about frame wear. 10, 11 and 12 are probably the most relevant in physics terms, since they deal with the general physics of collisions (though not with sustained forces (like the pulling of strings), and have some material on the distribution of force if you have an open mind about how it applies. The whole of part 2 on stroke production isn't really relevant at all. In Part 3, there are a few things worth taking a look at, though again there's nothing on the long term effects. Chapter 26 has a decent overview of string physics. Chapter 33 is the closest to home, in that it deals with some of the forces of stringing a racquet, but again nothing that describes any effects on the materials of the frame over time. And obviously Part 4 is irrelevant, since it's mainly a discussion of ball bounce and spin. There are also a few bits back in Chapter 2 about racquet construction that are tangentially relevant, since they suggest some of the properties of graphite grames, though not if you're looking for a specific comparison formula.

Instead of studying the wrong book, however, think about your experience as a tennis player (and hopefully as a stringer). How many times have you seen a healthy racquet crack in the normal course routine hitting. If you think back to all the times you saw a racquet break during normal hitting with the ball striking only the center of the string plane, the total would almost certainly be zero, unless you happened to have a very old or majorly flawed frame. That's because this isn't that hard on a frame. Now think about all the times you've seen a frame break while stringing. While not dozens of times, any stringer who has strung for more than a few years, has seen a frame break on the machine at some point, even though the tensions being applied are well under the 100 lbs you cited as typical ball impact. This is because the force is being applied ACROSS the frame...a direction that it's not built to take repeated forces in. I'm not sure what is so difficult to grasp about this. Frames often break while stringing, and vary rarely while normal playing is going on.

How about another example from real life. If you try to smash a racquet by throwing it at the ground with the face aimed at the ground and try to break it, it's VERY hard to do. It takes a strong adult with a considerable effort to do this. However, even a kid can break his racquet by throwing it down against the edge of the hoop. Safin does this almost every match he plays (if he's losing):) Often it even happens by accident. I'm trying to help you get this here, and am not what else I can do to communicate the basic idea that it's much easier to damage a frame by applying force parallel to the face (the direction in which stringing occurs) than perpendicular to it (the direction in which ball impact occurs). I'm also not sure why you're determined to believe that stringing forces have no physical impact on a frame. But maybe if you let go of trying to apply formulas from the one book and instead apply a more general knowledge of tennis experience, you'll see it. It doesn't require a lab full of physicists in California or Laurel, Maryland to explain these ideas.

bsandy
10-26-2007, 11:43 AM
Tension distributed over two strings instead of one is half the tension. So no, do not let anyone "double-pull" while stringing your racquet.

Wrong ! ! !

bsandy
10-26-2007, 11:46 AM
Someone with an RDC needs to test this.

LPShanet
10-26-2007, 12:28 PM
Someone with an RDC needs to test this.

I think they have, although I don't know the numbers specifically. I seem to remember that it's not half since it is one string, but it is lower, due to both the added string length and the friction around the frame/grommet points. And it would vary depending on the specific racquet, angle of grommet, etc.

knasty131
10-26-2007, 03:21 PM
I think the length of the string would be irrelevant to how tight it would actually be...I see how the friction from the grommet might allow the tension to be a little less but regarding length of the string, if you were to take a Head Ti.S7 (very long mains) and a Wilson PS 6.0 85 (relatively short mains) and strung it at 60 lbs. although it may feel different the 60 lbs. is an exact measurement. This leads me to believe that the length of the string over 2 mains would be irrelevant in the consideration of the argument that the tension would differ in comparison to just stringing one main.

LPShanet
10-26-2007, 03:56 PM
I think the length of the string would be irrelevant to how tight it would actually be...I see how the friction from the grommet might allow the tension to be a little less but regarding length of the string, if you were to take a Head Ti.S7 (very long mains) and a Wilson PS 6.0 85 (relatively short mains) and strung it at 60 lbs. although it may feel different the 60 lbs. is an exact measurement. This leads me to believe that the length of the string over 2 mains would be irrelevant in the consideration of the argument that the tension would differ in comparison to just stringing one main.

That may also be correct, I'm not sure...it might only be "stringbed stiffness" that is affected. There are certainly drops in "effective tension" associated with length, but there may not be actual ones.

knasty131
10-26-2007, 05:36 PM
That may also be correct, I'm not sure...it might only be "stringbed stiffness" that is affected. There are certainly drops in "effective tension" associated with length, but there may not be actual ones.

For all I know it's all wives' tales and for all I know is that I have gotten so used to the feel of my racket strung by pulling two mains (if there even is a difference) that it seems right. Until there is extremely concrete evidence that it is bad, I will choose to be stubborn in my thinking lol. Even if that evidence does come out, I probably won't change my mind because I have gotten used to it and wouldn't want to fix what's not broke.