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View Full Version : Can someone explain this? (who knows what they're talking about)


FH2FH
01-07-2007, 08:10 AM
I just got a stringer. Until I found a reference tension, my normal tensions were just way too tight. My stringer is nearly 10% tighter than the jobs I'm used to getting. While 10% doesn't seem like much, it's quite noticeable and drastically affected my shots. On the same racquet at 58lbs, I had to swing out for the ball to go beyond the service line. A day later at 52lbs my 3/4 swings send the ball near the baseline.

(And NO, it isn't because I did one job completely different. This is about my 10th job and I'm stringing them in about 45 minutes. I'm addicted!! :grin: )

Some here will point out that drastic tension changes alone will only increase or decrease the velocity of the ball by something like 1% or so. While that may be true, where it lands on the court is not 1% deeper or shorter. I want to better understand what happens here (trampoline effect, dwell time, etc???) that causes major changes in depth of the shot.

Can someone help? Please don't reply with conviction if you don't know what the hell you're talking about, haha. We have enough subjective BS on this board anyway. ;) Thanks!!

LttlElvis
01-07-2007, 08:35 AM
We need more info. What kind of stringing machine do you have? And what kind of stringing machine did you previously have your racquets strung with ? Drop weight, crank, or electronic. This makes a big difference. And by the way 10 % is large enough difference for most of us to notice.

You have only strung 10 racquets, so don't think you are an expert yet. Stringing is all about CONSISTENCY. Your previous stringer may have been stringing at XX lbs. Your new machine may read XX lbs. and be totally different. Remember the # lbs. is just a reference and you have to find out what is good for you.

Dropweights are accurate since they rely on gravity. Well calibrated electronics are very consistent and accurate. If you are using a crank, it is easy and quick. But to be consistent with a crank, you need to place the tensioning head at the same starting position if possible, and crank in a nice even pace. Changing positioning and crank pace results in uneven tensioning.

Another factor is type of string but I am assuming you are using the same type of string before you got your machine. # lbs on different strings are always different due to quality and elasticity.

FH2FH
01-07-2007, 08:40 AM
I'm using a dropweight. Previous jobs were on a crank. I'm not really wondering why there are differences, just why 10% is so noticeable (since ball velocity apparently doesn't change much).

PBODY99
01-07-2007, 09:22 AM
Can someone help? Please don't reply with conviction if you don't know what the hell you're talking about, haha. We have enough subjective BS on this board anyway

I'll reply, but remember that feel is subjective. You stated that a you are surprised by the difference 10% gives, well now you know what you read is true. Tension does matter to players, the why I've never seen proof positive in my 35 years of stringing. I've believe that it is the feedback you get from the hit.
In wood racket days, most players had a favorite and string jobs were used to a point you just couldn't today< I marveled at the fact that Tracey Austin had the same 4th Right main string worn on five frames when I saw her on a VA SLIMS practice court>.

Since you have now "dialed in" your tension for this machine, enjoy until it changes . Also you will understand why the non-stringers who play this game sometimes won't believe you when you tell them it may take a couple of stringings to dail in their perfect tension.:)

FH2FH
01-07-2007, 10:37 AM
Thanks for the reply. With your experience I'm sure you know of what you speak. Feeling/feedback is certainly part of it. I was hoping for someone like a physicist to chime in.

Maybe it is as simple as the string/racquet combo that just works ideally in a certain range. I mean other than the obvious 55-65lbs recommendations, poly lower/gut higher, etc, there has to be an ideal tension for a particular string on a particular racquet (for a particular player) to be most effective. I know that is common sense, but it still seems like strings/stringing is something of a magic science. There should be clearer guidelines, not so much guessing, right?

For example, I've played with SPPP at 55 and 58lbs and it literally felt like two different racquets. That just annoys the hell out of me and I'd like a good explanation of why, LOL. ;) Is the string or racquet really that sensitive? ...since other players report the same thing I assume it isn't just me.

Pusher
01-07-2007, 11:37 AM
I just got a stringer. Until I found a reference tension, my normal tensions were just way too tight. My stringer is nearly 10% tighter than the jobs I'm used to getting. While 10% doesn't seem like much, it's quite noticeable and drastically affected my shots. On the same racquet at 58lbs, I had to swing out for the ball to go beyond the service line. A day later at 52lbs my 3/4 swings send the ball near the baseline.

(And NO, it isn't because I did one job completely different. This is about my 10th job and I'm stringing them in about 45 minutes. I'm addicted!! :grin: )

Some here will point out that drastic tension changes alone will only increase or decrease the velocity of the ball by something like 1% or so. While that may be true, where it lands on the court is not 1% deeper or shorter. I want to better understand what happens here (trampoline effect, dwell time, etc???) that causes major changes in depth of the shot.

Can someone help? Please don't reply with conviction if you don't know what the hell you're talking about, haha. We have enough subjective BS on this board anyway. ;) Thanks!!


Changes in string tension will change the angle of deflection so that a shot with higher tension will land shorter than one with lower tension. Ball speed is pretty much irrevelent-at least that is my understanding.

downey stringing master
01-07-2007, 01:16 PM
i dont drop it by 10% no point the results are far better

ChicagoJack
01-08-2007, 12:15 PM
Hello FH2FH ;)

See my replies 3 & 6 in link provided. I'm not a physicist, but I am comfortable offering an explanation to your question in an accurate way. It is an experimentally observed fact that even large drops in tension produce amazingly small changes in rebound ball velocity. Yet the end result of tension change can feel quite different, in terms of impact sensation to the player. The ball trajectory will also result in quite noticable changes in depth. The lab and the court are not at odds with each other. You just need to be properly introduced to the happy couple.

http://tt.tennis-warehouse.com/showthread.php?t=110490

Best regards
-Jack

FH2FH
01-08-2007, 12:48 PM
Rebound angle. Now we're getting somewhere!! :)

FH2FH
01-08-2007, 01:03 PM
This is also an interesting thread [effect of lower tensions]: http://tt.tennis-warehouse.com/showthread.php?t=78045

ChicagoJack
01-08-2007, 01:11 PM
This is also an interesting thread [effect of lower tensions]:
http://tt.tennis-warehouse.com/showthread.php?t=78045

There is an abundance of factually unsupported statements in that thread - specifically regarding the relationship btwn low tension and spin, and the intent/conclusions of the Sheffield study. If you'd like to hear my take on the issue, which is supported by experimentally observed fact, you can find it here.
http://tt.tennis-warehouse.com/showthread.php?t=106870
-Jack

Kevo
01-08-2007, 01:48 PM
I agree that it mostly has to do with feel, but there is probably a lot that we don't understand about ball/string interaction.

I can state that I have found what I would call the 2x4 threshold on some frames and string combinations. On my RDX 500 mid I could string Ashaway Liberty ( a very soft syn gut ) at 60/57 lbs. of tension and it felt great and had pretty good power. However, if I strung it straight up at 60lbs. it felt like a 2x4 and had very little pop. It's very much like you describe. On a weirder note, Ashaway Dynamite 17 at 62lbs. straight up on that same frame felt kind of cushy and low powered at the same time. That one had more to do with the zyex than the tension, but many people have reported Dynamite feeling boardy at much lower tensions, so it was odd. Feel is a subjective thing and you kind of have to try these things out for yourself. That's why being able to do your own stringing is so great.

travlerajm
01-08-2007, 08:45 PM
Lower tensions give you significantly more power. Period.

The lab results prove it, but the studies available confuse the issue because the data are presented with respect to the racquet frame of reference. When translated to the court frame of reference (the frame of reference that matters), the lab results prove that lower tensions give significantly more power.

The data presented in the racquet frame of reference can cause someone to mistakenly believe that the energy imparted to the ball is almost independent of tension. This is not the case. Lower tensions transfer significantly more energy to the ball, but you need to translate the data to the court frame of reference in order to grasp this.

The Sheffield results show that 40 lbs tension gives you about 10% more ball velocity than 70 lbs for a typical topspin groundstroke. The authors of the Sheffield article mention the need to translate to the court frame of reference, but they never actually presented the calculations.

See this thread for more details:

http://tt.tennis-warehouse.com/showthread.php?t=112110

Steve Huff
01-08-2007, 09:46 PM
First, I'm making these assumptions:
1. they are both strung with the same type of string
2. the rackets are the same
3. the grip size on the rackets are the same
4. the rackets have approximately the same wear on them

If all of these are true, I'd attribute the difference in the inconsistency of the stringing (you've only done 10, so I'd imagine there's still quite a bit of inconsistency), or you are using a racket that is very tension sensitive (old Fischers used to be very tension sensitive--as in, only a few pound range to get good playability)

bad_call
01-09-2007, 07:33 AM
stringing is a science...kinda like dialing in boost.

FH2FH
01-09-2007, 08:46 AM
I agree; it's obvious lower tension does offer more depth. What I didn't understand before was rebound angle. Thanks!!

I would like to take the next step here and discuss tension/spin. It is:

INCREASED when the racquet:
A. takes a more vertical path
B. is swung faster
C. face is more closed.

DECREASED when the racquet :
A. takes a more horizontal path
B. speed is reduced
C. face remains open

Everyone agree so far?

Now remove swing speed from the equation. Also assume we want the ball to land 3 feet inside the baseline; the reason for this is because depth is important. With low tesions, it's requires less energy to close the racquet face and swing in a more veritical path; both which increase spin, correct? So which offers more spin?

Assuming you can keep the ball in the court, a lower tension offers increased spin for a given swing speed. Stringing tighter only increases the chances that your shots will land shorter and you will tire quicker, although they should land in a smaller radius [more control by limiting the dynamics of rebound angle, i think?].

If you look at the factors which reduce spin, this is generally what beginners will be doing (slow swings, open racquet face, horizontal swings, ...and very little spin). This is a good way to hit a clean ball.

If you look at Federer and Nadal, they both use low tensions, have fast swings, and use excessive spin. So why are they limiting their chances of clean contact? Because they have the timing and discipline to do so ...and rely, as many advanced players do, on topspin to keep the ball inside the lines.

Pete Sampras setup, higher tensions yet heavy spin, may have been possible because he used full gut, may have used a heavier racquet, and possibly swung fast enough to negate the effect of high tensions. I would be interested to see what Muster used since his tensions were high as well; 90lbs? I assume it would be full gut. Both were very strong physically as well. Nadal is also extremely powerful, but he also hits the ball with the most spin currently.

mucat
01-09-2007, 10:26 AM
One thing very important is the strength of the player. With a high tension racket, at impact, if a player is not strong enough, the force of the ball will push back the racket result in lose of energy and shorter ball. That why a strong arm or a sound techique is required to use a high tension racket. And that's also why a high tension racket is not a good defensive setup.

With low tension racket, at impact, the ball actually push back the stringbed more, so the arm take less of the impact and the arm got push back less, results in more comfortable and less strength dependent and better ability for the player to guide the ball.

IMO, if a player is strong enough to handle a high tension racket, less deformation of the stringbed will result in less energy loss, but the player is strong enough so his arm does not get push back. On the other hand, a strong player with a low tension racket will always lost some of his maximum speed because the stringbed deformation.

If a player is not strong enough to handle a high tension racket, his arm will pushed back by the force of the impact and result in energy loss. On the other hand, a low tension racket will give weaker player the ability to handle heavy ball and even handle them under defensive situation, because the strongbed absorb most of the impact.

I think the whole thing is just boil down to finding the tension that allow you to hit at maximum deep without hitting outside the court (too much).

bad_call
01-09-2007, 11:07 AM
interesting post mucat. i don't consider myself a weak player and i've just liked a lower tension (within mfg range) cause it felt better when contacting the ball. to each his own.

mucat
01-09-2007, 12:46 PM
interesting post mucat. i don't consider myself a weak player and i've just liked a lower tension (within mfg range) cause it felt better when contacting the ball. to each his own.

By weak, I mean physically not as strong, not a lower level player, hope I didn't confuse anyone. Also, there is another dimension to the whole thing. It is the spin. Low tension racket allow the player to spend less energy to fight off the incoming ball, which means more energy can be spend on applying spin to the ball. Personally, I have tried tension so low that, my swing path was becoming too steep and I hit the bottom of the frame more than usual, 1-2 lbs higher later the problem was solved.

FH2FH
01-09-2007, 01:04 PM
Mucat, I agree with that. I guess I could have made my post more concise. I can't blame that on the coffee today b/c I haven't had any!! ChicagoJack and Travelerajm really seem to understand what's happening, as some others have, with small differences (splitting hairs?) in the areas they disagree. Overall, very informative anyway. I was just trying to sum things up, and hope I did so accurately.

Well, I *think* I have a better idea now of what's happening with lower tensions and the ultimate outcome, or preference, toward lower or higher tensions. I think as I've played, I've focused too much on tension being the factor in my accuracy and not enough on the fact that I should have tried learning to swing at lower speeds and used lower tensions to reduce shock on my arm. Now if I can just make my body do what my brain is trying to tell it...