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TW Professor
08-27-2010, 08:46 AM
Check out the new TWU article based on our experiments with interstring friction. We have measured the coefficient of friction on about 30 strings (and will strive to do many more as time permits and make a full-fledged tool out of it).

http://twu.tennis-warehouse.com/learning_center/COF.php

vamos2050
08-27-2010, 09:11 AM
great tool! thanks for taking your time

Bud
08-27-2010, 09:28 AM
Some string company should create a natural gut with a durable Teflon™ coating :)

GPB
08-27-2010, 10:00 AM
What a report! Thanks for spitting out all this info into your learning center.

olliess
08-27-2010, 10:01 AM
Fascinating results. Thanks for this post.

Gasolina
08-27-2010, 11:23 AM
I was hoping to see Tour Bite in the test.

Great article. One thing that needs to be taken into account here is even though a gut/poly hybrid would produce the biggest spin, it won't necessarily give you that "just before the line" dropping of a full poly.

As much spin as you could generate with a hybrid, you still need the dampening of power from a poly to effectively use that spin.

Gasolina
08-27-2010, 11:32 AM
I wonder if a multi/poly hybrid would get as much spin as a gut/poly hybrid?

scotus
08-27-2010, 02:40 PM
So it looks like a gut-M and RPM-Blast-X would be the ultimate spin monster...

... for the über rich.

Don't Let It Bounce
08-28-2010, 02:20 PM
So it looks like a gut-M and RPM-Blast-X would be the ultimate spin monster...t does look like it, assuming that the slipperiest poly will always make the slipperiest gut/poly hybrid. I wonder if we can assume that? (I hope not, given how much less Cyclone costs than RPM Blast.)

08-28-2010, 06:07 PM
Check out the new TWU article based on our experiments with interstring friction. We have measured the coefficient of friction on about 30 strings (and will strive to do many more as time permits and make a full-fledged tool out of it).

http://twu.tennis-warehouse.com/learning_center/COF.php

So TW Professor,
the strings that retain tension better,meaning less string movement,therefore less spin potential,am I right?

wrxtotoro
08-28-2010, 06:20 PM
Then what about Kevlar? It's known to produce extreme bite on the ball but does it increase any spin in reality?

GameSetMatch
08-29-2010, 04:53 AM
How can a gut hybrid produce more spin that a full bed poly? That just makes no sense.

I think you need to a test a full bed of natural gut as a 'control' factor to the experiment.

Interesting that X1 is one of the worst spin producing strings you can get.

08-29-2010, 05:10 AM
How can a gut hybrid produce more spin that a full bed poly? That just makes no sense.

I think you need to a test a full bed of natural gut as a 'control' factor to the experiment.

Interesting that X1 is one of the worst spin producing spins you can get.

wait a while to see if u know what i mean. ;)

Gasolina
08-29-2010, 09:21 AM
So it looks like a gut-M and RPM-Blast-X would be the ultimate spin monster...

... for the über rich.
True... but what about the remaining 95% of the population?

Given that TCS was #2 based on the test, it would make sense as the poly cross for a "reasonable" setup.

How about the mains? Since the reason why gut@mains made #1 was because of it allows the poly to freely move... would the Dynamite be a good alternative since it offers the closest to gut feel? Maybe a POGS would work too?

String both at around 45lbs and maybe we have a winner.

gatorbait01
09-01-2010, 04:39 AM
Has anyone here done a side by side comparison with rackets strung up with full poly and gut mains, poly crosses?? Does the hybrid really produce more or equal spin to the full bed of poly?

Gasolina
09-01-2010, 07:40 AM
Has anyone here done a side by side comparison with rackets strung up with full poly and gut mains, poly crosses?? Does the hybrid really produce more or equal spin to the full bed of poly?
Didn't they just do that in the article? Well they tested the lowest COF which contibutes to spin.

Although what good is a spin if you can't dampen your power well to use it right? Maybe that's why a lot of people would claim that full poly = more spin.

JediMindTrick
09-01-2010, 07:44 AM
Now we know why Federer and Djokovic put the gut in the mains and the poly in the crosses.

AR15
09-01-2010, 07:50 AM
Perhaps string savers will provide even more spin by allowing the strings to move back into position, after impact, faster.

Gasolina
09-01-2010, 08:15 AM
Perhaps string savers will provide even more spin by allowing the strings to move back into position, after impact, faster.
I don't think that's the complete story. I think on order to produce the spin, the strings would have to go back first and then snap back with little friction. If you had string savers, then won't the string movement be prevented?

Xenakis
09-01-2010, 08:27 AM
Interesting stuff, thanks.

gatorbait01
09-01-2010, 10:10 AM
[QUOTE=Gasolina;5004508]Didn't they just do that in the article? Well they tested the lowest COF which contibutes to spin.

The article said it produces the most string movement which like you said is a contributing factor to spin. There could be more to it that is not understood. I have doubts because if gut mains and poly crosses produced the most spin why would nadal use full poly?

After reading the article I strung my racket up with gut mains and cyberflash crosses. The racket played much different, but I definately didn't notice more spin than with full cyberflash. There may have been just as much spin but the gut was 15L much thicker than the 17 guage I'm used to with cyberflash so the ball was coming off the racket at a much lower trajectory. It felt like I had a closed string patten rather than a 16/19. As an aside I really liked the lower trajectory and could hit flatter and more accurate shots. The racket also felt lower powered with the gut mains I assume because of the 15L guage.

09-01-2010, 10:29 AM
I can't agree with the fact that some strings were rated better than the SP Tornado.I have tested so many strings and the Tornado really grabs the ball and generates more spin than some of those mentioned on the article.

Centered
09-01-2010, 10:34 AM
Two hypotheses arise to explain these. First, gut's super-slipperiness when installed in the mains may be due to oils that are released as the gut main nothches. The nothcing occurs as the cross strings saw across the main. When the hybrid is reversed (gut crosses, polyester mains), the gut no longer notches. The polyester main moves up and down along the length of the gut, rubbing and fraying individual guts filaments as it does so. These fraying filiments then curl, intertwine, and project from the string, acting as microscopic obstacles impeding the movement of the polyester main string.
But there's no oil being exuded from polyester, so what accounts for its lower COF? If oil is good, will we see people oiling their strings before matches in the future? What about teflon coatings?

Plus, the bottom chart shows two nylon strings with a lower COF than VS Team. That would imply gut doesn't have "super-slipperiness" in comparison with those two nylon strings:

Prince Synthetic Gut Original 16, Nylon, 0.124
Gosen OG-Sheep Micro Super 16L, Nylon, 0.145
Babolat VS Team 17, Gut, 0.147

If sideways movement of the mains is so important, what about lowering string tension? It also seems like strings that move around more would be better for spin, making what people call "excessive string movement" a good thing. Is there a chart that shows the difference between strings with an actual tension of 40 lbs versus strings with an actual tension of 60?

Also, what's the second hypothesis?
Friction between strings is determined by the surface characteristics of the main and cross that are moving against each other as well as the force pushing them together.

This 'same spin' result is true whether the string is a rough or smooth, thin or thick, or round or square.
Hmm. I'm confused. The first part makes it sound, along with the "gut oils" hypothesis, that surface condition (slippery surface) is really important. The second part makes it sound as if the surface condition makes little difference.
And then, the string must retain enough elastic energy stored in its sideways stretch to overcome that same friction in returning to its starting position.
Please be more specific about this. Does polyester "retain its elastic energy" better than other strings, which accounts for its greater spin potential? If so, how?

Gasolina
09-01-2010, 10:40 AM
The article said it produces the most string movement which like you said is a contributing factor to spin. There could be more to it that is not understood. I have doubts because if gut mains and poly crosses produced the most spin why would nadal use full poly?
I think the reason why power spin hitters (Nadal / Verdasco) stay away from Gut/Poly hybrids is because it's too lively. Contrary to popular belief, your ball can have a lot of spin, but still fly out of the park.

A lot of us when we hear spin, we think its the thing that magically makes the ball fall down before the baseline and jump back up making the shot hard to return. In reality, spin, for all it's intents and purposes is just the ball spinning, even if the ball sails long or not.

People use full poly because #1 control and #2 spin. A gut/poly hybrid might produce the most spin but the full poly might produce the most useful spin. Meaning the low powered poly would actually contribute to the ball coming down before the baseline.

Can you imagine Nadal and Verdasco's forehands with a gut hybrid? It would fly all the way to the 5th row.

Centered
09-01-2010, 10:43 AM
In reality, spin, for all it's intents and purposes is just the ball spinning...
Not really. Topspin causes a ball to arc from low to high and then down. Hitting flat causes the ball to go straighter/deeper. It's the spin in the topspin shot that keeps it in the court.

Sure, it's possible to hit a heavy spin ball that's out, but that doesn't mean the spin isn't helping to keep the shot in the court.

Gasolina
09-01-2010, 10:46 AM
Sure, it's possible to hit a heavy spin ball that's out, but that doesn't mean the spin isn't helping to keep the shot in the court.
Yes of course, topspin helps in keeping the ball in play. But I'm willing to bet the low powered poly contributes more than the spin.

Also, the poly allows you to take gigantic windshield wipers to generate the spin in the first place.

Centered
09-01-2010, 10:52 AM
Yes of course, topspin helps in keeping the ball in play. But I'm willing to bet the low powered poly contributes more than the spin.
No, it's the spin RPMs that have increased. Borg's topspin RPMs were much lower than Nadal's, and Borg's shots were less powerful. The combination of greater muscle, a larger stiffer lighter racquet, a more extreme western grip, poly, and very high racquet speed have enabled Nadal to hit with more topspin than his predecessors.

Kevlar is less powerful than poly, being much stiffer, and it did not enable the same level of spin production and big hitting, according to Agassi who used it and then switched to poly.

Anyway, back to my first post. Here is the part of the chart that shows gut with a less impressive COF than two nylon strings:

http://i52.tinypic.com/2yjo7bn.jpg

Gasolina
09-01-2010, 11:01 AM
Anyway, back to my first post. Here is the part of the chart that shows gut with a less impressive COF than two nylon strings:

http://i52.tinypic.com/2yjo7bn.jpg
I stand corrected. The Gut rating leaves me confused as well. But my thinking is the slipperyness of the Poly makes the COF lower. I mean if you just run your fingers over some gut, it is pretty sticky.

Gasolina
09-01-2010, 11:06 AM
This makes a POGS/TCS experiment a lot more viable

Centered
09-01-2010, 11:09 AM
I stand corrected. The Gut rating leaves me confused as well. But my thinking is the slipperyness of the Poly makes the COF lower. I mean if you just run your fingers over some gut, it is pretty sticky.
The chart just doesn't make much sense with the description of gut as being "super slippery". Gut also comes with various coatings, some of which may reduce slickness.

Gasolina
09-01-2010, 11:11 AM
The chart just doesn't make much sense with the description of gut as being "super slippery". Gut also comes with various coatings, some of which may reduce slickness.
I thought the article pointed out that the gut's oils (which came from the poly slicing into it) made the the gut slide a lot easier?

gatorbait01
09-01-2010, 11:17 AM
A lot of us when we hear spin, we think its the thing that magically makes the ball fall down before the baseline and jump back up making the shot hard to return. In reality, spin, for all it's intents and purposes is just the ball spinning, even if the ball sails long or not.

People use full poly because #1 control and #2 spin. A gut/poly hybrid might produce the most spin but the full poly might produce the most useful spin. Meaning the low powered poly would actually contribute to the ball coming down before the baseline.

Can you imagine Nadal and Verdasco's forehands with a gut hybrid? It would fly all the way to the 5th row.[/QUOTE]

Something tells me that if a gut hybrid would produce more spin, then hardly anyone would use full poly. I think nadal and vedasco could adjust there swings to take advantage of the added spin and added comfort of gut mains. I could be wrong. I was hoping if anyone has done a good side by side comparison where the only variable would be the different strings. I'll do one soon, just gotta get some thicker guage cyberflash.

AR15
09-01-2010, 11:18 AM
I don't think that's the complete story. I think on order to produce the spin, the strings would have to go back first and then snap back with little friction. If you had string savers, then won't the string movement be prevented?

Not sure. I have limited experience with string savers, but I recall that my strings still slipped with them.

JediMindTrick
09-01-2010, 12:22 PM
TW Professor,

Can we please get the numbers for Prince Recoil? Since Prince is claiming that this is a very slippery string, it would be interesting to see this claim quantified.

Thanks!

JediMindTrick
09-01-2010, 12:25 PM
It also seems like strings that move around more would be better for spin, making what people call "excessive string movement" a good thing.

All strings move, but the slippery ones (like polys and Recoil) snap back, making it look likey didn't move. Because they snap back, they give more spin. So "excessive string movement" = "strings didn't snap back" = "less spin" = "a bad thing'.

Racer41c
09-01-2010, 01:42 PM
So does this explain why my racquet smells like WD-40 all the sudden?

olliess
09-01-2010, 02:27 PM
But there's no oil being exuded from polyester, so what accounts for its lower COF?
It's smooth, among other reasons.

If oil is good, will we see people oiling their strings before matches in the future? What about teflon coatings?
I think Prince Recoil (mentioned by another poster) and Babolat N.Vy (among others) are already trying slippery coatings, so probably yes. WD-40 I don't know about.

Plus, the bottom chart shows two nylon strings with a lower COF than VS Team. That would imply gut doesn't have "super-slipperiness" in comparison with those two nylon strings:
Gut was only "super slippery" in the special case of gut mains sliding against poly crosses, right? COF can be different between two materials than between instances of the same material and also be sensitive to exactly how those surfaces engage (hence the "slippery oil" hypothesis).

If sideways movement of the mains is so important, what about lowering string tension?
Lowering string tension should reduce the friction if the COF stays roughly the same. However, the "snapping" action of the string in the horizontal (which seems to be the mechanism for imparting spin) also comes from the tension, so these two effects ought to run counter to each other.

It also seems like strings that move around more would be better for spin, making what people call "excessive string movement" a good thing. Is there a chart that shows the difference between strings with an actual tension of 40 lbs versus strings with an actual tension of 60?
I thought excessive string movement referred to strings which move out of place and don't come back (so that you have to sit there and twiddle with your strings between points like they all did in the old days).

Please be more specific about this. Does polyester "retain its elastic energy" better than other strings, which accounts for its greater spin potential? If so, how?
When your multifilament gets knocked out of place and doesn't come back, it retains its elastic energy but it doesn't release it back to the ball. The poly, despite being less elastic than other strings, is able to slide back and immediately return the elastic energy built up by deflecting the string sideways.

DE19702
09-01-2010, 05:23 PM
Although lower tensions may make it easier for the stings to slide apart, as posted above, this also has the effect of reducing the speed at which they snap back. Apparently, it is this snapping back that imparts spin upon the ball.

With regard to the question why full gut is not more slippery than a gut/poly hybrid, it may be because of adhesion between the mains and the crosses since they are both the same material.

It should be relatively a simple matter to chop up a bunch of gut, mix it with some kind of solvent, boil away the solvent and then measure the amount of oil in the string. I haven't seen any evidence that says that there is oil in gut, but it makes sense.

It was interesting to note that the Prince Synthetic Gut has a coefficient of friction less than the multis and overall looks like a half-decent string from that point of view.

Centered
09-01-2010, 07:11 PM
snip
Some of these explanations don't seem to add up, like the sections of the article I highlighted.

It's smooth, among other reasons.
Not all poly is smooth and some nylon strings are very smooth, plus the article said it doesn't matter what the shape of the poly is. Well, a round string is going to be smoother than a hexagonal one because it lacks sharp edges.

Plus the article said rough textured strings don't make a significant difference.
Gut was only "super slippery" in the special case of gut mains sliding against poly crosses, right? COF can be different between two materials than between instances of the same material and also be sensitive to exactly how those surfaces engage (hence the "slippery oil" hypothesis).
I think it's still too fuzzy in the way it's explained/documented to make good sense. I fail to see why gut would exude special oils when it's used with poly and not something else, or why it has a lower COF than two of the tested nylon strings if it exudes oil and gets "super slippery".
The poly, despite being less elastic than other strings, is able to slide back and immediately return the elastic energy built up by deflecting the string sideways.
Why/how? That's what I'd like to see explained, too.

Centered
09-01-2010, 07:15 PM
Can we please get the numbers for Prince Recoil? Since Prince is claiming that this is a very slippery string, it would be interesting to see this claim quantified.
Head claims some of its strings that have Teflon coatings are more powerful because of slipperiness, too. The grommets in some of its racquets are a similar case.

tarkowski
09-02-2010, 06:35 AM
I've played a gut main and poly cross for quite a while and have always felt that it is extremely spin friendly. More than my all gut setup, and more than the full bed of black code that I just tried. I chalked it up to the fact that for me, it is the most familiar and what my swing path is grooved to. But based on TW findings, it looks like it is indeed more spin friendly in absolute terms.

Outside of the 'oil release due to gut notching on poly theory', there is also the fact that gut is a much more elastic string than poly. Compared to a full poly setup, gut on the mains with a poly cross provides that combination of poly keeping the string bed from deforming backward for more forward launch, and giving the gut the best chance to bend sideways for maximum spin.

This is how I feel it when playing it as well. I also feel that with this set up, I really need to be 'on' my game, swinging full and confident to maximize this set up. I also need to swing flatter. Catching a ball late, or exaggerating the low-to-high motion in this set up really sends the ball long. I think this may also be what Chris (TW) was eluding to when he said that for him, an all poly set up provides more controlled spin because the launch angle is quite a bit less.

Just my humble opinions and ramblings as we all grapple with the issue!

Gasolina
09-02-2010, 06:40 AM
I think it's still too fuzzy in the way it's explained/documented to make good sense. I fail to see why gut would exude special oils when it's used with poly and not something else, or why it has a lower COF than two of the tested nylon strings if it exudes oil and gets "super slippery".

Why/how? That's what I'd like to see explained, too.
Maybe because the gut was tested as a hybrid only with a poly? They didn't really test the gut in a hybrid with a syn gut or with a multi.

09-02-2010, 06:56 PM
* String texture or shape makes no difference to spin
Didn't it show that ALu Rough Produces more spin than Alu Power??
* String pattern makes no difference to spin
It does make a huge difference.
Why don;t tey make a racket with 45 mains and 50 crosses and play with that racket and then go play with a 16x19?I bet you could get more spin from a 16x19.
* String tension makes no difference to spin
On the very same article it shows the same string strung at 62 and 52 and the one with 52 had low COF therefore producing more spin.
* String gauge makes no difference to spin-
Same string at lower gauge can produce more spin.
* String material makes no difference to spin
Didn't it say the polyester produces more spin than nylon?
I don't really believe some of what they said at all,very contradictory.

Centered
09-02-2010, 07:15 PM
Yeah, I think some major retooling is needed. To me it looks a bit like a convoluted advertisement for RPM Blast. I will assume that wasn't intentional.

bsandy
09-03-2010, 04:03 AM
Another reason to wax your gut.

. . . Bud

kcjim
09-03-2010, 05:10 AM
I've tried gut mains and poly crosses twice. I loved it on my serves....way more spin. Really abrupt (only word that comes to mind) spin that just snapped as it cleared the net. The problem with this setup is my forehands kept going just long. It felt great, but in the end I just didn't have the sense or ability to reign in my forehand side. Probably a form issue with my forehand. I don't know.

TW Professor
09-03-2010, 09:45 AM
Several points of clarification:

So it looks like a gut-M and RPM-Blast-X would be the ultimate spin monster...

This quote echoes several others equating low COF and spin. COF is only one of the facilitators of string movement, snap back, and spin. But other properties of a individual string can act to negate or reverse benefits of the low COF. The COF experiments simply distinquish the slippery strings from the sticky ones. Other experiments will distinquish strings from each other on the other spin facilitating properties. The goal being able to decipher which strings have the greatest NET spin potential. Determining the COF ranking is just one step along the way. So do not simply interpret a low COF as "the best spin string," but rather, that it has one very important property that acts in favor of spin. It may or may not be the "best."

So TW Professor,
the strings that retain tension better,meaning less string movement,therefore less spin potential,am I right?

For a given string, higher tension will tend to increase the COF between strings, first because the tension pushes the strings together with greater force and second because the stiffer stringbed will create a greater normal force at impact which also pushes the strings together more.

Plus, the bottom chart shows two nylon strings with a lower COF than VS Team. That would imply gut doesn't have "super-slipperiness" in comparison with those two nylon strings:

Prince Synthetic Gut Original 16, Nylon, 0.124
Gosen OG-Sheep Micro Super 16L, Nylon, 0.145
Babolat VS Team 17, Gut, 0.147

COF depends on the TWO surfaces. The COFs given in the quote are for each string on itself. The hybrids involve two different materials. In each instance the surfaces will interact differently both atomically and morphologically.

Also, what's the second hypothesis?
Quote:
Friction between strings is determined by the surface characteristics of the main and cross that are moving against each other as well as the force pushing them together.

This 'same spin' result is true whether the string is a rough or smooth, thin or thick, or round or square.
Hmm. I'm confused. The first part makes it sound, along with the "gut oils" hypothesis, that surface condition (slippery surface) is really important. The second part makes it sound as if the surface condition makes little difference.

There are two completely different situations here: the ball-to-string friction interaction and the string-to-string interaction. The first is a special case because, as the article explains, friction tends to disappear before the end of the impact in the first case but not in the second. So string shape, texture, gauge may make a difference in spin in the string-to-string interaction but not in the ball-to-string interaction.

TW Professor,

Can we please get the numbers for Prince Recoil? Since Prince is claiming that this is a very slippery string, it would be interesting to see this claim quantified.

Thanks!

There will be more COFs coming....

If sideways movement of the mains is so important, what about lowering string tension?

Lowering tension will reduce inter-string friction but it also tends to lower the energy return in the string (you can see this by going to http://twu.tennis-warehouse.com/learning_center/reporter.php and searching energy return at the different tensions). This means the string will snap back more slowly. Thus, it may or may not snap back quick enough, far enough or with enough force to significantly affect the spin. It will depend on the string.

Catching a ball late, or exaggerating the low-to-high motion in this set up really sends the ball long. I think this may also be what Chris (TW) was eluding to when he said that for him, an all poly set up provides more controlled spin because the launch angle is quite a bit less.

Friction not only puts torque on the ball to create spin, but it slows the ball down as it travels across the strings. String movement and snap back will do the same. The more the ball is slowed down parallel to the strings, the steeper the launch angle will be and the farther the ball will travel farther.

* String texture or shape makes no difference to spin
Didn't it show that ALu Rough Produces more spin than Alu Power??
* String pattern makes no difference to spin
It does make a huge difference.
Why don;t tey make a racket with 45 mains and 50 crosses and play with that racket and then go play with a 16x19?I bet you could get more spin from a 16x19.
* String tension makes no difference to spin
On the very same article it shows the same string strung at 62 and 52 and the one with 52 had low COF therefore producing more spin.
* String gauge makes no difference to spin-
Same string at lower gauge can produce more spin.
* String material makes no difference to spin
Didn't it say the polyester produces more spin than nylon?
I don't really believe some of what they said at all,very contradictory.

Much of the answer to this is explained above with respect to all these properties having a different significance depending on whether you are talking ball/string interaction or string/string interaction. Before it was determined that string movement and snap back were so important to topspin, the statement that COF, material, pattern, etc. did not matter to spin was "correct" as far as it went. But given that string movement is important, each of these needs to be experimentally revisited, but for different reasons and from a different point of view. So the COF article has revisted COF, the material articles (http://twu.tennis-warehouse.com/learning_center/spinexperiment.php and http://twu.tennis-warehouse.com/learning_center/stringmovement.php have revisted material, and we are presently conducting experiments on patterns.

Stay tuned...

Centered
09-03-2010, 11:07 AM
COF depends on the TWO surfaces.
Then you had better do some tests with hybrid setups that don't just involve gut + poly, given that two nylon strings had lower COFs in your chart than VS Team gut.

Also, please test the new Dynamite Soft and also regular Dynamite 17 for the String Database. Thanks.

JT_2eighty
09-03-2010, 11:50 AM
Then you had better do some tests with hybrid setups that don't just involve gut + poly, given that two nylon strings had lower COFs in your chart than VS Team gut.

That's really probably not necessary:

1) we know low friction *helps* the spin of a shot. (technique, ability, grip, etc still play their role).
2) we know that gut is the most elastic string type. (multi will always be 2nd place to gut).
3) we know that strings that are NOT monofilaments (gut, multis, syn gut), will notch, thus increasing the friction between strings over use (they typically start notching after an hour or few), while monofilaments (i.e. polys), do not notch in the same way, preserving their low friction qualities (polys are known for maintaining an even stringbed because of both their stiffness and smoothness and resistance to notching).

Therefore, gut mains (most elastic for most movement and snap back) and poly crosses (resistance to notching and low friction) is the best setup for pure spin, while also benefitting in the power and feel departments due to gut mains. Having just half the stringbed be poly is enough to create a low-friction, good-spin setup. Try it yourself and use it for days/weeks. You will see how the gut continues to slide back in place, unlike what will occur with the same gut in a full bed. The obvious downside to not using full poly is control, due to the launch angle discussions. More spin does not always equate to more control, this gets into player differences now, as some prefer max spin, and some just amped spin.

Thus, multi mains on poly crosses will be similar, but not as good as gut mains (see 1-3).

Everyone give the Prof a breather, dang. You should all be able to take the info here, and extrapolate to your favorite string or hybrid if not included. Keep experimenting, and if your oncourt results defy the results in a lab, that's FINE, actual results > theory.

JT_2eighty
09-03-2010, 12:25 PM
Something tells me that if a gut hybrid would produce more spin, then hardly anyone would use full poly. I think nadal and vedasco could adjust there swings to take advantage of the added spin and added comfort of gut mains. I could be wrong. I was hoping if anyone has done a good side by side comparison where the only variable would be the different strings. I'll do one soon, just gotta get some thicker guage cyberflash.

Of course they *could* adjust their swings, but that is another piece of the puzzle as to why some use full poly and some gut/poly hybrid. The full poly typically allows for a more controllable shot, due to the trajectory (launch angles) off the stringbeds that will vary from hybrid or full beds of x,y,z.

I do love all the science about how this all works and value it's importance and what we can learn from it to help our games, but let us not forget how much things like technique, talent, subjective likes and dislikes, personalities, etc play into a player's choice of equipment and style. All of these more intangible aspects of one's game still make up the majority of the puzzle. Equipment changes will only get you so far; there's no mystery why one man's trash is another's treasure. We see it on these boards, on the tour, and at the club.

bsandy
09-03-2010, 12:25 PM
Does anyone other than me wonder:

What was their methodology?

How many test cases were there to get such smooth curves?

How do they go from strings snapping back adding spin being a theory in April and now it's law?

. . . Bud

Bartelby
09-03-2010, 03:51 PM
This idea has been around for quite a while.

Does anyone other than me wonder:

What was their methodology?

How many test cases were there to get such smooth curves?

How do they go from strings snapping back adding spin being a theory in April and now it's law?

. . . Bud

Centered
09-03-2010, 06:04 PM
That's really probably not necessary:

1) we know low friction *helps* the spin of a shot. (technique, ability, grip, etc still play their role).
2) we know that gut is the most elastic string type. (multi will always be 2nd place to gut).
3) we know that strings that are NOT monofilaments (gut, multis, syn gut), will notch, thus increasing the friction between strings over use (they typically start notching after an hour or few), while monofilaments (i.e. polys), do not notch in the same way, preserving their low friction qualities (polys are known for maintaining an even stringbed because of both their stiffness and smoothness and resistance to notching).

Therefore, gut mains (most elastic for most movement and snap back) and poly crosses (resistance to notching and low friction) is the best setup for pure spin, while also benefitting in the power and feel departments due to gut mains. Having just half the stringbed be poly is enough to create a low-friction, good-spin setup. Try it yourself and use it for days/weeks. You will see how the gut continues to slide back in place, unlike what will occur with the same gut in a full bed. The obvious downside to not using full poly is control, due to the launch angle discussions. More spin does not always equate to more control, this gets into player differences now, as some prefer max spin, and some just amped spin.

Thus, multi mains on poly crosses will be similar, but not as good as gut mains (see 1-3).

Everyone give the Prof a breather, dang. You should all be able to take the info here, and extrapolate to your favorite string or hybrid if not included. Keep experimenting, and if your oncourt results defy the results in a lab, that's FINE, actual results > theory.
Your analysis is messed up. "Synthetic gut", for instance, is a monofilament.

I'll believe that gut + poly is the best setup for spin once I see the actual testing data for other hybrids -- including those that involve nylon strings with a better COF than gut.

Centered
09-03-2010, 06:10 PM
And then, the string must retain enough elastic energy stored in its sideways stretch to overcome that same friction in returning to its starting position.
Please be more specific about this. Does polyester "retain its elastic energy" better than other strings, which accounts for its greater spin potential? If so, how?
I'm still wondering about this. What, specifically, would make polyester a better cross string than something else?

Stiffness? Aramids like Vectran and Kevlar are even stiffer.

Smoothness? Any string material can be made with a smooth outer coating, even with Teflon on the outside.

What is this "retention of elastic energy" and how does it differ between strings? Polys have the lowest energy return (efficiency) numbers in the TW database (which is strangely missing aramid strings like Kevlar altogether).

JT_2eighty
09-03-2010, 09:46 PM
I'm still wondering about this. What, specifically, would make polyester a better cross string than something else?

Stiffness? Aramids like Vectran and Kevlar are even stiffer.

Smoothness? Any string material can be made with a smooth outer coating, even with Teflon on the outside.

What is this "retention of elastic energy" and how does it differ between strings? Polys have the lowest energy return (efficiency) numbers in the TW database (which is strangely missing aramid strings like Kevlar altogether).

You should honestly string up all the combos and see for yourself. Ever hear of spaghetti stringing? Gut m/poly x mimics this the best out of any. It sounds like you've not tried or compared them because it is like night and day on court.

JT_2eighty
09-03-2010, 09:51 PM
Your analysis is messed up. "Synthetic gut", for instance, is a monofilament.

I'll believe that gut + poly is the best setup for spin once I see the actual testing data for other hybrids -- including those that involve nylon strings with a better COF than gut.

Have you ever used syn gut? Does it not notch on you due to it's outer core (which polys do not, hence my point)?

Again, instead of waiting for data, go on court and feel the difference. It's there where our answers should be gleaned the best, aye?

Play tennis :0

TimothyO
10-19-2010, 05:16 AM
Has anyone tried any of the suggestions from this thread? Any new TW research in the offing?

Fascinating stuff! Very tempted to seek out a "slippery" cross and flexible main. Sounds like a ballista! :)

lefty10spro
10-19-2010, 05:32 AM
I put Prince Natural Gut 16 in the mains and Prince Recoil 16 in the crosses since I cannot tolerate polys in any form (pain - I'm 51!). 1 word - unbelievable!

TimothyO
10-19-2010, 05:53 AM
I put Prince Natural Gut 16 in the mains and Prince Recoil 16 in the crosses since I cannot tolerate polys in any form (pain - I'm 51!). 1 word - unbelievable!

How would you describe:

Spin Potential...

Control...

Power...

I find myself gravitating towards low power, high control/spin potential configurations.

lefty10spro
10-19-2010, 07:53 AM
This combo is .076 on the TW COF list so it will reallly spin it. Because of the spin, your control is good, but probably has too much power for you. My backup has Recoil in the mains and a 16 gauge poly in the crosses. This combo is #2 on the TW list with a COF of .062!! This would fit your needs perfectly, but caused me minor discomfort.

TimothyO
10-19-2010, 08:07 AM
This combo is .076 on the TW COF list so it will reallly spin it. Because of the spin, your control is good, but probably has too much power for you. My backup has Recoil in the mains and a 16 gauge poly in the crosses. This combo is #2 on the TW list with a COF of .062!! This would fit your needs perfectly, but caused me minor discomfort.

Thanks!

I should have added comfort as a primary concern too! Spin doesn't matter if one's arm hurts.

I'm thinking about Recoil in the crosses and a soft, thin multi-filament in the mains with an eye towards less bounce than a natural gut.