TW string comfort ranking, from softest to stiffest

Centered

Hall of Fame
Stiffness of strings, from low to high, using TW's data, with rough categorization. (As stiffness increases, shock increases, comfort decreases.)

Click here for TW Comfort Ranking, medium tension version

40 lbs reference tension, fast swing:

Ultra soft
Pacific Prime Gut 16, 81.2
Wilson Natural Gut 17, 82.3
Babolat VS Team Gut 17, 86.3
Pacific Prime Gut 16L, 86.3
Pacific Classic Natural Gut 16, 89.7

Extremely soft
Pacific Tough Gut 16L, 90.9
Babolat VS Touch 16, 90.9
Babolat Tonic + 16, 90.9
Ashaway Dynamite Soft 18, 91.4
Wilson Natural Gut 16, 94.3
Klip Legend 16 Uncoated, 97.2

Super soft
Klip Armour Pro 16, 102.2
Pacific Tough Gut 16, 102.3
Ashaway Dynamite Soft 17, 102.3
Ashaway Dynamite WB 16, 104.6
Ashaway Dynamite 17, 108.6
Polyfibre Poly Hightec 18 1.10, 109.2

Very soft
Gosen Nanoblend 17, 112.0
Pacific PMX 17, 114.3
Isospeed Axon Multi 16L, 116.0
Volkl Gripper 17, 116.6
Prince Premier w/ Softflex 16, 117.2

Quite Soft
Wilson Hollow Core 16, 120.0
Wilson Sensation Supreme 16, 120.0
Babolat Xcel 16, 120.6
Weiss Cannon Explosiv 1.30, 120.6
Wilson Reaction 16, 121.2
Gamma Asterisk Spin 16, 121.2
Gosen TecGut Remplir 16, 121.7
Pacific PMX 16L, 121.7
Wilson Hollow Core Pro 17, 122.3
Prince Premier w/ Softflex 17, 122.3
Tecnifibre Pro Mix 16, 122.3
Tecnifibre E-Matrix 16, 122.9
Prince Premier LT 17, 124.0
Gamma Professional 16, 124.6
IsoSpeed Pulse 17, 124.6
Wilson Enduro Tour 18, 124.6
Tecnifibre E-Matrix 17, 124.6
Head Sonic Pro 16, 125.2
Polyfibre Cobra 17, 125.2
Polyfibre Poly Hightec 17, 125.2
Polyfibre TCS Rapid 16L, 125.7
Volkl Gripper 16, 125.7
Head Fibergel Power 16, 125.7

Soft
Gosen Compositemaster II 16, 126.3
Polyfibre TCS 17, 126.3
Polyfibre Hightec Premium 17, 126.9
Polyfibre Viper 17, 128.0
IsoSpeed Pulse 16, 128.0
Prince Premier LT 18, 128.6
Tecnifibre Pro Mix 17, 129.2
Babolat Xcel Power 17, 129.7
Gamma Revelation 16, 129.7
Gosen A.K. Control 16, 130.3
Babolat Xcel Premium 17, 130.9
LaserFibre Supernatural Gut Pro Stock 16, 131.4
Tecnifibre TGV 16, 131.4
Gosen Powermaster II 16, 131.4

Moderately soft
Head FXP Power 16, 132.0
IsoSpeed Professional Classic 17, 133.2
IsoSpeed Control 16, 133.2
Dunlop Tour Performance 16, 133.2
Kirschbaum Touch Multifibre 16, 133.2
Gamma Asterisk 16, 133.2
Wilson NXT 17, 133.2
IsoSpeed Control Classic 16, 133.7
Gosen OG Sheep Micro 17, 133.7
Klip Kicker 16, 133.7
Yonex Tournament 80 Spin 15L-16, 133.7
Gamma LiveWire XP 16, 134.3
Gamma TNT2 Pro Plus 16, 134.3
Ashaway Synthetic Gut 16, 134.3
Babolat Addiction 17, 134.3
Klip Scorcher 16, 134.3
Tecnifibre XR3 17, 134.9
Head RIP PerfectPower 16, 134.9
Gamma ESP 16, 135.4
Gosen PowerMaster I 16, 136.0
Solinco Vanquish 16, 136.0
Head PerfectControl 16, 136.6
Pacific Power Twist 16L, 136.6
Technifibre NRG-2 16, 136.6
Gosen Polylon Comfort 16, 137.2
Polyfibre TCS 16L, 137.2
Klip Synthetic Gut 16, 137.2
Klip Excellerator 16, 137.2
Gamma Asterisk Tour 16, 137.7
Prince Synthetic Gut Multifilament 17, 137.7
Wilson Enduro Tour 17, 137.2
Wilson Sensation 17, 137.2
Volkl Power-Fiber II 16, 137.7

Medium
Technifibre X-One 16, 138.3
Prince Poly Spin 3D, 138.3
Gosen Compositemaster I 16, 138.3
Ashaway Liberty 16, 138.9
Babolat Attraction 16, 138.9
Klip Venom 16, 138.9
Prince Synthetic Gut 18 Duraflex, 138.9
Gosen Nanosilver 17, 139.4
Babolat Conquest 16, 139.4
Gamma Zo Tour Rough 16, 139.4
Gamma Professional Spin 16, 140.0
Tecnifibre Multi-Feel 16, 140.0
Gamma Prodigy 16, 140.6
Dunlop M-Fil Tour 16, 141.2
Babolat FiberTour 16, 141.2
Tecnifibre XR3 16, 141.7
Wilson NXT OS, 141.7
Prince Synthetic Gut Multifilament 16, 141.7
Dunlop Explosive Poly Max 16, 142.3
Babolat Addiction 16, 142.3
Head Fibergel Spin 16, 142.3
Gosen OG Sheep Micro 18, 142.3
Yonex Tournament 50 16L, 142.3
Polyfibre Viper 16L/1.25, 142.3
Tourna Irradiated 16, 142.9
Babolat Xcel Power 16, 143.4
Head Synthetic Gut PPS 16, 143.4
Head ETS 16, 143.4
Head FXP 16, 143.4
Dunlop Comfort Synthetic 16, 144.0
Pacific Premium Power X 16L, 144.0
Gamma WearGuard Synthetic Gut 16, 144.0
Isospeed Energetic 17, 144.6
Wilson K-Gut Pro 16, 144.6
Prince Topspin Plus 16, 144.6
Gosen AK Pro 17, 144.6
Dunlop Synthetic Gut 16, 145.2
Dunlop X-Life Synthetic 15L, 145.2
IsoSpeed Pyramid 16, 145.2
Prince Recoil 16, 145.2
Wilson NXT 16, 145.2
Wilson Sensation 16, 145.2

Somewhat stiff
Technifibre X-One 17, 145.7
IsoSpeed Energetic Plus 16, 145.7
Prince Tournament Nylon 15L, 146.3
Gosen OG Sheep Micro Super 16L, 146.3
Gamma Zo Twist 16, 146.3
Wilson NXT Max 16, 147.4
Polyfibre Poly Hightec 16L, 147.4
Pacific Power Line 17, 147.4
Wilson NXT Tour 17, 148.0
Dunlop Explosive Synthetic 16, 148.0
Pacific Power Line 16L, 148.6
Kirschbaum Helix 16, 149.2
Prince Lightning XX 16, 149.2
Prince Syn Gut Duraflex 16, 149.2
Polyfibre TCS 16, 149.2
Wilson K-Gut 16, 149.7
Prince Syn Gut Original 17, 149.7
Solinco Tour Bite 17, 149.7
Gosen OG-Sheep Micro 16, 150.3
Polyfibre Hightec Premium 16L, 150.3
Weiss Cannon Silverstring 120, 150.9
Gosen AK Pro 16, 150.9
Wilson NXT Tour 16, 150.9
Solinco Outlast 17, 150.9
Wilson Extreme Synthetic Gut 16, 151.4
Prince Lightning XX 17, 151.4

Rather stiff
Wilson Synthetic Gut Extreme 17, 152.0
Gosen Nanocubic 16, 152.0
Boris Becker Bomber 17, 152.6
Head Synthetic Gut 16, 152.6
Kirschbaum Spiky Shark 17, 153.2
Polyfibre Poly Hightec 16, 153.7
Polyfibre Hightec Premium 16, 154.3
Babolat Super Fine Play 16, 154.9
Luxilon M2 Pro 125/16, 154.9
Prince Synthetic Gut Duraflex 17, 154.9
Gamma TNT2 Rx 16, 154.9
Forten Sweet 16, 155.4
Prince Topspin W/ Duraflex 15L, 155.4
Solinco Revolution 17, 156.0
Wilson Stamina 16, 156.6
Prince Synthetic Gut Original 16, 157.2
MSV Co-Focus 16L, 157.2
Weiss Cannon Turbo Twist 17L, 158.3
Gamma Synthetic Gut 16, 158.9

Stiff poly strings:

Tier 1 (stiff):
Weiss Cannon Scorpion 1.22, 162.9
Prince Tour 17, 163.4
Luxilon Big Banger TiMO 17L, 164.6
Kirschbaum Super Smash Spiky, 164.6
Head Ultra Tour 16, 165.2
Ashaway Monogut 17, 165.7
Weiss Cannon Silverstring 1.25, 166.9
Tourna Big Hitter Silver 17, 167.4
Luxilon Big Banger Timo 18, 168.6
Boris Becker Bomber 16, 169.2
Luxilon Big Banger ALU Power Rough 16L, 169.7
Luxilon Big Banger Ace 18, 170.3
Volkl Cyclone 16, 170.3
Weiss Cannon Turbotwist 17, 170.9
Babolat Pro Hurricane 18, 171.5
Gosen Polylon 16, 172.6
Klip Hardcore 16, 172.6
Pacific ATP Poly Power Pro 16L, 172.6

Tier 2:
Kirschbaum Pro Line II 1.30, 173.2
Solinco Tour Bite 16, 174.3
Isospeed Axon Mono 16L, 175.5
Signum Poly-Plasma Pure 17L, 175.5
Prince Tournament Poly 17, 175.5
Luxilon Big Banger ALU Power Fluoro 17, 175.5
Luxilon Monotec Zolo 16, 177.2
Luxilon M2 Plus 16, 177.2
Luxilon Adrenaline 16, 179.5
Signum Tornado 16, 180.6
Signum Poly Speed Spin 1.28, 181.7
Ashaway MonoGut 16L, 181.2
Technifibre Black Code 18, 181.7
Kirschbaum Spiky Shark 16, 182.3
Signum Poly-Plasma Pure 17, 182.3
Wilson Enduro Gold 16, 183.5
Luxilon Big Banger ALU Power 16L, 183.5
Babolat Duralast 16, 184.0
Pacific Poly Force 16L, 184.0
Signum Hyperion 17, 184.6

Tier 3:
MSV Focus Evo 17, 185.2
Luxilon Big Banger ALU Power Spin 16, 185.2
Signum Plasma HEXtreme 16L, 185.7
Kirschbaum Super Smash Spiky 16, 185.7
Kirschbaum Helix 17, 185.7
Kirschbaum Competition 16, 186.3
Babolat Pro Hurricane 16, 186.9
Solinco Outlast 16, 187.5
Luxilon Big Banger Original 16, 187.5
Luxilon Big Banger Rough 16, 188.6
Signum Plasma Pure 16L, 188.6
Prince Tour 16, 188.6
Prince Poly EXP 17, 189.2
Luxilon Big Banger XP 16L, 190.3
Solinco Revolution 16, 191.5
Pacific Poly Force Xtreme 16L, 192.0
Prince Tournament Poly 16, 193.2
Signum Tornado 17, 193.2
Babolat Revenge 17, 194.3
Signum Poly Megaforce 17, 193.7
Kirschbaum Super Smash 16, 193.7
Pacific X Force 18, 193.7
Weiss Cannon Scorpion 1.33, 194.9
Kirschbaum Touch Turbo 1.30, 194.9
Yonex PolyTour 130/16, 194.9
Babolat Duralast 17, 194.9

Tier 4:
Luxilon Monotec Zolo 15L, 197.7
Topspin Cyber Flash 16, 199.5
Signum Poly-Plasma Pure 16L, 199.5
Dunlop Comfort Poly 17, 200.0
Wilson Enduro Mono 16L, 200.6
Signum Hyperion 16, 200.6
Babolat RPM Blast 16, 201.2
Gamma Monoblast 16, 201.2
MSV Focus Evo 16, 201.2
Babolat Ballistic Polymono 16, 201.7
Kirschbaum P2 16, 201.7
Kirschbaum Pro Line I 1.30, 202.9
Gamma Zo Ice 16, 204.6
Wilson Enduro Pro 16, 205.7
Tecnifibre Pro Red Code 18, 204.6
Babolat Pro Hurricane Tour 16, 205.7
Prince Twisted 16L, 205.7
Luxilon Monotec Super Poly 16L, 208.0
Tourna Big Hitter Blue 17, 208.0
Tourna Big Hitter Blue 16, 208.0

Tier 5:
Technifibre Black Code 17, 208.6
Weiss Cannon MatchPower 1.25, 209.2
Tourna Big Hitter 16, 209.7
Kirschbaum Long Life 15, 209.7
Pacific X Force 17, 212.0
Leopard Plus Control 16, 213.7
Tecnifibre Pro Red Code 17, 214.3
Pacific Poly Force 17, 214.9

Tier 6:
Tecnifibre Pro Red Code 16, 218.3
Signum Pro Poly Megaforce 16, 218.9
Tecnifibre Black Code 16, 221.2
Technifibre Polyspin 16L, 221.7
Gamma Zo Power 16L, 223.5

Tier 7 (very stiff):
Gamma Zo Magic 16, 229.2
Klip K-Boom 16, 232.6
Wilson Enduro Tour 16, 232.6
Babolat Revenge 16, 248.6

Super stiff

Ashaway Composite XL Pro 15L (Vectran/Nylon)
Ashaway Composite XT Pro 16 (Vectran/Nylon)

Extremely stiff
Kevlar

Ultra stiff
Prince Pro Blend (main)

RSI for aramids.
 
Last edited:

flashfire276

Hall of Fame
Looks correct for the most part! Remember, they' comparing all kinds of strings. So if you see a soft poly (Babolat Pro Hurricane) on stiff, it's stiff because it's compared to gut!
 

Mig1NC

Professional
I wonder where Tecnifibre X-Code is going to come into the mix. Probably "Tier-1" poly.
 

COPEY

Hall of Fame
Rather stiff
Kirschbaum Spiky Shark 17, 153.2
Luxilon M2 Pro 125/16, 154.9
Prince Synthetic Gut Duraflex 17, 154.9
Gamma TNT2 Rx 16, 154.9
Forten Sweet 16, 155.4
Prince Topspin W/ Duraflex 15L, 155.4
Solinco Revolution 17, 156.0
Wilson Stamina 16, 156.6
Prince Synthetic Gut Original 16, 157.2
MSV Co-Focus 16L, 157.2
Weiss Cannon Turbo Twist 17L, 158.3
Gamma Synthetic Gut 16, 158.9

Forten Sweet 16 is listed as "Rather Stiff"? That what the data showed or is that simply an oversight?
 

nickarnold2000

Hall of Fame
Rather stiff
Kirschbaum Spiky Shark 17, 153.2
Luxilon M2 Pro 125/16, 154.9
Prince Synthetic Gut Duraflex 17, 154.9
Gamma TNT2 Rx 16, 154.9
Forten Sweet 16, 155.4
Prince Topspin W/ Duraflex 15L, 155.4
Solinco Revolution 17, 156.0
Wilson Stamina 16, 156.6
Prince Synthetic Gut Original 16, 157.2
MSV Co-Focus 16L, 157.2
Weiss Cannon Turbo Twist 17L, 158.3
Gamma Synthetic Gut 16, 158.9

Forten Sweet 16 is listed as "Rather Stiff"? That what the data showed or is that simply an oversight?
That's strange; Prince Syn Gut Duraflex 16, 149.2 is softer than Sweet 16??
Sweet feels softer and PSGD feels crisper, IMO.
 

Centered

Hall of Fame
Edit: New information: The softest & stiffest synthetic strings — TW test results — a visual guide

----- old post below -----

Anyone who has an issue with the testing data should contact the Tennis Warehouse folks who did the tests. The numbers I have posted are directly from the database that I linked to. I added the rough stiffness categories to make the results a bit easier to work with.

I wonder where Tecnifibre X-Code is going to come into the mix.
TW hasn't tested it. Black Code, E-Matrix, Multi-Feel, NRG-2, Polyspin, Pro Mix, Pro Red Code, TGV, X-One, and XR3 are tested.

I have updated the list to include all tested Technifibre strings.
 
Last edited:

COPEY

Hall of Fame
I don't have an "issue" with the data; I was just wanting an explanation. You went through the trouble to start this thread & post the data, so the expectation is that you would be prepared to answer questions.

I'm guessing the assumption is that people would use this info to purchase (or at the very least, consider) strings based on characteristics such as softness/stiffness. If that's true, then my question is why is Forten Sweet 16 listed under "Rather Stiff"? If you don't know, that's fine...and judging by your reply my guess is you don't.

If TW maintains that Forten should be considered "Rather Stiff", then I think it speaks volumes for how much weight should be given to data such as this. The bottom line should be, "regardless of what the numbers say, how it plays to you is law".
 

Centered

Hall of Fame
If that's true, then my question is why is Forten Sweet 16 listed under "Rather Stiff"? If you don't know, that's fine...and judging by your reply my guess is you don't. If TW maintains that Forten should be considered "Rather Stiff", then I think it speaks volumes for how much weight should be given to data such as this.
I've explained two times already that I am the one who organized the data into the rough stiffness categories to make the results easier to work with. You and others can take issue with those categories, but the stiffness numbers come directly from the database and form the basis of those categories. While we can argue endlessly about the specific range of the categories and their names, the stiffness data itself is from TW's tests and you'll have to ask them about it if you think it's erroneous.

Keep in mind that strings at low tension may perform differently at high tension. Swing speed also makes a difference in how a string feels. Some strings feel considerably stiffer with slow swing speeds than they do at high swing speeds.
 

Centered

Hall of Fame
Additionally, there is the issue of tension retention. Some strings hold tension poorly, like that ultra-thin Polyfibre poly that is second only to Dynamite in terms of soft synthetics at 40 lbs reference tension with a fast swing. Because of this, the actual stiffness of the material becomes just part of the feel.

If you have two strings, A and B, that have the same actual material stiffness and string A loses twice as much tension, then string A will feel softer.

A number of poly strings end up in the same range as monofilament nylon because of tension loss. Although they're made from a stiffer material, they feel just as soft to the player because they're at a lower actual tension in comparison with the nylon strings.
 

COPEY

Hall of Fame
Not sure why you're getting defensive, but ok. Again, I don't have an issue with the data; I have a question about a specific string in a specific category.

I'm quite aware of performance variations based on tension differences and swing speed. That's actually common sense if you ask me.

Lastly, the answer to my question is "you don't know." You just post the data; you don't question it. I'll seek out the TW folks.

Thanks - that's all I needed. ;-)
 

Centered

Hall of Fame
Not sure why you're getting defensive, but ok.
I'm "getting" to posting answers to your questions, which have hardly been cordial.
Again, I don't have an issue with the data; I have a question about a specific string in a specific category.
The categories are derived from the data, as you can see if you look at the number progression from category to category, as well as the numbers within the categories.
I'm quite aware of performance variations based on tension differences and swing speed. That's actually common sense if you ask me.
Ask a stupid question... I was simply trying to help you and others deal with your apparent issues with the TW results.
Lastly, the answer to my question is "you don't know."
Wrong. I do know. The Forten Sweet number is what Tennis Warehouse's testing at 40 lbs reference tension with a fast swing yielded, just as was posted in the OP.
I'll seek out the TW folks.
Exactly what I already suggested, eh? Well done.
 
Last edited:

COPEY

Hall of Fame
This was my first question, and I'm not sure how you interpreted that as not being cordial...but ok:

"Forten Sweet 16 is listed as "Rather Stiff"? That what the data showed or is that simply an oversight?"

Your reply was...

"Anyone who has an issue with the testing data should contact the Tennis Warehouse folks who did the tests."

Yes, you posted more information after the fact, which is appreciated, however, I think I'll take you up on your first suggestion. :) Thanks again!
 

Centered

Hall of Fame
Here are the Forten Sweet 16 numbers, for those who are interested:

40 lbs, Fast, 155.4
40 lbs, Slow, 165.2
40 lbs, Medium, 165.7

51 lbs, Fast, 188.6
51 lbs, Slow, 190.3
51 lbs, Medium, 190.9

62 lbs, Fast, 221.2
62 lbs, Medium, 224.6
62 lbs, Slow, 226.3
 

Racer41c

Professional
Rather stiff
Kirschbaum Spiky Shark 17, 153.2
Luxilon M2 Pro 125/16, 154.9
Prince Synthetic Gut Duraflex 17, 154.9
Gamma TNT2 Rx 16, 154.9
Forten Sweet 16, 155.4
Prince Topspin W/ Duraflex 15L, 155.4
Solinco Revolution 17, 156.0
Wilson Stamina 16, 156.6
Prince Synthetic Gut Original 16, 157.2
MSV Co-Focus 16L, 157.2
Weiss Cannon Turbo Twist 17L, 158.3
Gamma Synthetic Gut 16, 158.9

Forten Sweet 16 is listed as "Rather Stiff"? That what the data showed or is that simply an oversight?

I would agree with this, I was disappointed how stiff Sweet 16 is. I use it as a "stiff" syn gut cross.
 

Mig1NC

Professional
One thing I have always wondered is that stiff nylons may be more elastic than similarly rated polys. Perhaps what we feel as far as the stiff nylon being softer than a poly with the same stiffness rating is due to the elasticity whereby the nylon stretches to the rated stiffness level whereas the poly may just lock into that level with no give.

Or something along those lines...

Just wondering out loud. Not trying to force my completely unscientific theory on anybody.
 

Centered

Hall of Fame
One thing I have always wondered is that stiff nylons may be more elastic than similarly rated polys. Perhaps what we feel as far as the stiff nylon being softer than a poly with the same stiffness rating is due to the elasticity whereby the nylon stretches to the rated stiffness level whereas the poly may just lock into that level with no give.

Or something along those lines...

Just wondering out loud. Not trying to force my completely unscientific theory on anybody.
It's a good question with some basis in the data. Take a look at this:

40 lbs:

Pacific Tough Gut 16, fast, 102.3
Dynamite WB 16, fast , 104.6
Poly Hightec 18, fast, 109.2
Gamma Professional 16, fast, 124.6
NRG-2 16, fast, 136.6

Wow! A poly that's nearly as soft as gut? I guess polyester really is a soft material after all, right?

Dynamite WB 16, medium, 109.7
Tough Gut 16, medium, 112.0
Poly Hightec 18, medium, 123.4
Gamma Professional 16, medium, 129.2
NRG-2 16, medium, 141.2

Hmm...

62 lbs reference:

Pacific Tough Gut 16, slow, 114.9
Gamma Professional 16, slow, 163.4
Dynamite WB 16, slow, 172.0
NRG-2 16, slow, 173.2
Poly Hightec 18, slow, 228.6

Egad! Polyester is actually stiff at higher tensions.

Pacific Tough Gut 16, fast, 78.3
Dynamite WB 16, fast, 142.3
Gamma Professional 16, fast, 172.0
NRG-2 16, fast, 177.7
Poly Hightec 18, fast, 192.6

So, the answer to your question appears to be that nylon becomes increasingly softer than poly as reference tensions increase. Even the softest poly in the TW tests at low tension quickly stiffened with increasing reference tension. The actual tension of that Polyfibre string, which is 1.10mm, is very low at 40 lbs reference tension because it lost around 29.3 lbs, giving it an actual tension of just 11.05 lbs.

Similarly, natural gut holds its tension really well so it's truly softer than any synthetic even at the low reference tension of 40 lbs. The softest poly may be stiffer than the stiffest nylon at the same actual tension, but can be softer or the same at the same reference tension because of tension loss.

Swing speed also makes a difference. The Polyfibre string, when compared with NRG-2, has a larger range of stiffness depending upon swing speed:

low tension
Poly Hightec 18, fast, 109.2
NRG-2 16, fast, 136.6
Poly Hightec 18, medium, 123.4
NRG-2 16, medium, 141.2
NRG-2 16, slow, 141.7
Poly Hightec 18, slow, 144.6

high tension
NRG-2 16, slow, 173.2
Poly Hightec 18, slow, 228.6
NRG-2 16, fast, 177.7
Poly Hightec 18, fast, 192.6

This difference, though, is likely mostly related to the thinness of the Hightec.
 
Last edited:

Centered

Hall of Fame
Poly versus nylon -- stiffness and actual tension. I used polys with high tension retention numbers and eliminated those with low retention numbers, except in one case which has an asterisk.
the last number is total tension loss

40 lbs:

slow swing
Forten Sweet 16, 165.2, 9.3
Gamma Synthetic Gut 16, 166.3, 9.9
Head Synthetic Gut 16, 168.0, 9.9
Pro Hurricane 18, slow, 209.7, 15.7
Axon Mono 16L, slow, 215.5, 14.8

fast swing
Wilson Stamina 16, 156.6, 10.4
Prince Syn Gut Original 16, 157.2. 10.6
Gamma Synthetic Gut 16, 158.9, 10.4
Babolat Pro Hurricane 18, 171.5, 16.1
IsoSpeed Axon Mono 16L, 175.5, 15.0

51 lbs:

fast swing
Babolat Pro Hurricane 18, 185.2, 19.0
Prince Syn Gut Original 16, 191.5, 10.6
Babolat Super Fine Play 16, 191.5, 11.0
Head FXP Power 16, 194.3, 13.0
IsoSpeed Axon Mono 16L, 199.5, 17.4
Pacific X Force 18, 208.6, 18.7
Signum Pro Poly Megaforce 17, 213.2, 18.5
Tecnifibre Pro Red Code 18, 217.2, 18.3
Topspin Cyber Flash 16, 217.2, 19.0
Weiss Cannon MatchPower 1.25, 218.3 , 19.4
Kirschbaum P2 16/1.30, 218.9, 19.4
Wilson Enduro Pro 16, 219.5, 18.3
Tourna Big Hitter Blue 17, 222.3, 18.5
Gamma Zo Ice 16, 223.5, 19.2
Tecnifibre Pro Red Code 17 , 225.7, 18.5
Pacific X Force 17, 225.7, 18.3
Tecnifibre Polyspin 16L, 226.9, 18.5
Tecnifibre Pro Red Code 16, 232.0, 17.6
Pacific Poly Force 17, 233.2, 18.5
Signum Pro Poly Megaforce 16, 234.9, 17.6
Klip K-Boom 16/1.30, 237.2, 17.2
Gamma Zo Magic 16, 248.0, 17.2

62 lbs:

fast swing
*Signum Pro Plasma HEXtreme 16L/1.25, 160.6, 23.8
Pro Hurricane 18, 189.2, 18.7 pre-stretched
Prince Syn Gut Original 16, 214.3, 11.5
Babolat Pro Hurricane 17, 217.7, 17.9 pre-stretched
Babolat Super Fine Play 16, 219.5, 11.9
Gamma Synthetic Gut 16, 220.6, 11.5
Forten Sweet 16, 221.2, 12.8
Prince Synthetic Gut 17 Duraflex, 224.0, 5.7 pre-stretched
Gamma Synthetic Gut 16, 225.2, 3.3 pre-stretched
Babolat Super Fine Play 16, 225.2, 4.6 pre-stretched
Wilson Stamina 16, 227.5, 4.6 pre-stretched
IsoSpeed Axon Mono 16L, 230.9, 18.3
Forten Sweet 16, 233.7, 5.7 pre-stretched
IsoSpeed Axon Mono 16L, 250.9, 11.0 pre-stretched
Tourna Tourna Big Hitter Blue 17, 258.9, 13.7 pre-stretched
Signum Pro Tornado 17 (1.23), 265.7, 13.0 pre-stretched
Signum Pro Poly Megaforce 16, 266.3, 12.1 pre-stretched
Gamma Zo Magic 16, 266.3, 11.9 pre-stretched
Babolat Pro Hurricane Tour 17, 269.7, 13.7 pre-stretched
Tecnifibre Pro Red Code 16, 272.0, 12.1 pre-stretched
Klip K-Boom 16/1.30, 274.3, 11.9 pre-stretched
Tecnifibre Black Code 17, 275.5, 11.7 pre-stretched
Luxilon Monotec Zolo 15L, 279.5, 13.7 pre-stretched
Dunlop Comfort Poly 17, 284.6, 11.0 pre-stretched
Wilson Enduro Tour 16, 285.2, 13.5 pre-stretched
Babolat RPM Blast 16, 286.3, 13.2 pre-stretched
Babolat Pro Hurricane Tour 16, 288.0, 11.9 pre-stretched
Tecnifibre Black Code 16, 289.2, 10.8 pre-stretched
Babolat Revenge 16, 331.5, 11.5

I would really like to see pre-stretched data for medium and low tensions.

Anyway, the point of all this is that the stiffest nylon strings are softer than any poly at the same thickness and actual tension I would say. However, pre-stretched stiff nylon strings can be stiffer than a poly like Axon Mono 16L that's not pre-stretched, making the stiffness gap a bit smaller. Also, when polys and nylons are compared at the same reference tension, polys can be significantly softer due to tension loss. We really need to see pre-stretched data for the low and medium tensions, because few people want to string polys at 62 lbs.
 
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Centered

Hall of Fame
It must be a tension variable because many people have posted that Sweet feels like soft mush as compared to PSGD or Gosen Micro!
It's not what the testing data shows. In fact, Sweet 16 was the stiffest nylon string in one of the tests -- pre-stretched at 62 lbs.

Here are the RSI numbers for the 17 and 15L (62 lbs, fast swing):

Forten Sweet 17, 1.27mm, 194, 12.62 tension loss
Forten Sweet 15L, 1.36mm, 204, 11.55 tension loss
 

Centered

Hall of Fame
Here are the RSI numbers for comparison with TW's. Their tests are only at 62 lbs with a fast swing, however.

RSI String Selector 2010

These strings should be as soft or softer (at high tension) than Dynamite WB 16, according to RSI:

Head Perfect Power 17
Gamma Professional 18
Alpha Gut 2000 18
Ashaway Dynamite 17, 147 stiffness
Gamma Asterisk 17
Isospeed Professional 17
Isospeed Professional 17 (Classic)
Pro Supex Maxim Touch 1.25
Ashaway Powernick 18
Isospeed Control 16 (Classic)
Dunlop Dura Ace 17
Tecnifibre X One Biphase 18
Isospeed Control 16
Ashaway Super Nick XL Pro 17
Wilson K Gut Pro 17
Babolat Xcel Power 17
Ashaway Dynamite WB 16, 165 stiffness

There's a 20 point stiffness difference between the 17 gauge and 16 (really 15L) Dynamite strings in RSI's high tension fast swing test. Dynamite WB 16 clearly is softest at low tensions, so a good number of the above strings will be stiffer at low tensions.

For instance IsoSpeed Professional Classic 17 has a stiffness of 133.2 at low tension with a fast swing, per TW's tests, while Dynamite WB 16 has a stiffness of 104.6. So, the RSI tests would be improved if they would test their strings at low tension as well as at high tension.
 
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nickarnold2000

Hall of Fame
It's not what the testing data shows. In fact, Sweet 16 was the stiffest nylon string in one of the tests -- pre-stretched at 62 lbs.

Here are the RSI numbers for the 17 and 15L (62 lbs, fast swing):

Forten Sweet 17, 1.27mm, 194, 12.62 tension loss
Forten Sweet 15L, 1.36mm, 204, 11.55 tension loss[/QUOTE



I think I'll draw my own conclusions by actually playing and testing these strings on court. Thanks for taking the time to post the info. :)
 

Valjean

Hall of Fame
Have you contacted the TW Professor to ask him/her about the data, since you think it's faulty?
When TW's "Professor" next exchanges the current data mine for another still later, still more current version, I hope you are then as prepared to ask him to change his mind...
 

Centered

Hall of Fame
You can look at the RSI data for 62 lbs fast swing, but TW has not tested that string.

Here are strings with equal stiffness to MT 16 (1.30) in the RSI test. The strings scored a 190:

Tecnifibre NRG2 17
Ektelon Lightning XX w/Powerfoil 17
Yonex Tour Super 850 16
Isospeed Hybrid Long Life 16
Kirschbaum Touch Multifibre 1.25
Head Synthetic Gut PPS 17
Unique Tourna Irradiated 17
Klip Kicker 17
Gamma Live Wire XP 16
Babolat Addiction 17
Gosen OG Sheep Micro 18
Gamma Live Wire 16
Ashaway Synthetic Gut 17
 

mctennis

Legend
Centered, great info and thanks for posting this info. Good to have this as a reference all in one place. I love playing with a softer string.
 

Don't Let It Bounce

Hall of Fame
One thing I have always wondered is that stiff nylons may be more elastic than similarly rated polys.
What may explain that perception is that stiffness is a dynamic rather than static property; that is, the string's tension increases a lot (don't remember offhand how much, but check out Cross & Lindsay's Technical Tennis if you're interested) during the first half of the 5 milliseconds of contact between ball and string: ball hits string, string stretches and gets much stiffer, process is reversed as string ejects ball.

Check out this handy chart: gut, incredibly, has roughly the same stiffness at most any tension, so it will feel soft throughout the ball-string contact. Nylon gets stiffer as tension goes up. Polyester gets stiffer a little faster as tension goes up, so the green line has a sharper slope. The difference between nylon and poly isn't much, but it might help explain your perception.

The other thing that might help explain it, of course, is that humans have a limited capacity to isolate "stiffness" out of the grab bag of dozens of factors that make up a 5-millisecond tactile perception.

It does seem to follow from the data on this chart, incidentally, that the handful of synthetics that have gut-like stiffness don't have gut-like stiffness once the ball and string are in full contact – though, needless to say, they may still be soft enough for a given player to like them.
 

CP3

Banned
Wow, this list is amazing, it seems to be nearly comprehensive. Much thanks to TW for compiling it.

If I understand it correctly, every natural gut is superior to all synthetics, even the softest for protecting your arm...

Stiffness of strings, from low to high, using TW's data, with rough categorization. (As stiffness increases, shock increases, comfort decreases.)

40 lbs reference tension, fast swing:

Ultra soft
Pacific Prime Gut 16, 81.2
Wilson Natural Gut 17, 82.3
Babolat VS Team Gut 17, 86.3
Pacific Prime Gut 16L, 86.3
Pacific Classic Natural Gut 16, 89.7

Extremely soft
Pacific Tough Gut 16L, 90.9
Babolat VS Touch 16, 90.9
Babolat Tonic + 16, 90.9
Wilson Natural Gut 16, 94.3
Klip Legend 16 Uncoated, 97.2

Super soft
Klip Armour Pro 16, 102.2
Pacific Tough Gut 16, 102.3
Ashaway Dynamite WB 16, 104.6
Polyfibre Poly Hightec 18 1.10, 109.2

Very soft
Gosen Nanoblend 17, 112.0
Pacific PMX 17, 114.3
Isospeed Axon Multi 16L, 116.0
Volkl Gripper 17, 116.6
Prince Premier w/ Softflex 16, 117.2

Dynamite is the softest synthetic for this test.

Refer to RSI for aramids. The RSI tests are at 62 lbs, but you can see how much of a difference there is between the stiffest poly and aramids.

Also note that string gauge naming may be inaccurate.
 

marosmith

Professional
Centered, great info and thanks for posting this info. Good to have this as a reference all in one place. I love playing with a softer string.

Agreed. Normal people appreciate this info, only the strange ones take offense and attack the poster...
 

Centered

Hall of Fame
Wow, this list is amazing, it seems to be nearly comprehensive.
RSI tested more strings than TW, but their data isn't as broad. They only tested at 62 lbs with a fast swing, while the data in the opening post is from TW's testing at 40 lbs reference tension with a fast swing.

TW's testing is missing a good number of strings, including some it sells, like Dynamite 17, Dynamite Soft 17, Dynamite Soft 18, Gamma Professional 18, Liberty 15L, all aramids, and more. Hopefully more strings will be added soon.

TW also only did pre-stretch tests at high tension. I would like to see pre-stretch tests at low and medium tensions, since pre-stretching dramatically improved tension retention with most strings.
Much thanks to TW for compiling it.
They (and RSI for some of the data) did the testing. I compiled it from this tool.

If I understand it correctly, every natural gut is superior to all synthetics, even the softest for protecting your arm...
Natural gut is definitely the softest string and tends to remain soft even at high tensions, although some natural guts are significantly softer than others. It also holds its tension better than other string materials. Some find it more durable than multi-filament strings, especially those with fairly dense string patterns, high quality gut, and flat strokes.

Gut is not without flaws, though. It's difficult to string. If a stringer notches the string (it will look like a white spot in the string), the gut will break quickly there. It unravels quickly if it gets wet and sometimes even in high humidity. Lower-quality gut may snap quickly, even on the stringing machine. Beginners may break it quickly because it is vulnerable to off-center mishits (shear stress). It is also expensive to produce.

Synthetic materials increase in stiffness as tension is increased, although how dramatic the increase is varies with material. Some polyester, for instance, may be soft in a very thin gauge at very low tension and becomes quite stiff at high tension. Zyex seems to be the best synthetic material in terms of comfort, especially at moderately low tensions and even more so with a thinner gauge string (Dynamite 17 is even softer than WB 16).

If you look at the data you quoted, you'll see that two natural gut strings are very close to Dynamite WB 16, a thick 1.41mm Zyex string, which means the Dynamite was practically as soft as those two strings at that reference tension after the TW impact tests were conducted. Part of this is because the Dynamite, being a synthetic, loses much more tension than natural gut, so its actual tension is significantly lower. With synthetic strings, as tension drops, so does stiffness. However, there is a range of stiffness depending upon the material and construction (gauge, filament thickness/shape). Aramids like Kevlar, for instance, are much stiffer than other strings even at the lowest tension, with many filaments, and with the thinnest possible gauge.

Zyex is rivaled by polyolefin, although it seems to have the edge. Although the data isn't yet available, I expect Dynamite Soft 18 (1.15mm) to be the softest synthetic string currently on the market. The 17 gauge should also be quite soft. I look forward to TW updating the database with the data for these new strings.

Regular Dynamite 17 remains a good buy at $7 a pack for 5+ packs, too. It will not likely be as soft as Dynamite Soft, but may be a bit more durable due to the thicker Zyex inner filaments. However, those recovering from tennis elbow should stick with the Dynamite Soft 18 or natural gut.
 
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mikeler

Moderator
...However, those recovering from tennis elbow should stick with the Dynamite Soft 18 or natural gut.


Other multis can be used by those with elbow problems. I can attest to this in addition to some people I play with. Just try one of the softer ones first. If your elbow still can't handle that, then try natural gut or just rest it.
 

Sublime

Semi-Pro
Super soft
Klip Armour Pro 16, 102.2
Pacific Tough Gut 16, 102.3
Ashaway Dynamite WB 16, 104.6
Polyfibre Poly Hightec 18 1.10, 109.2

LOL... if test data tells you a poly (any poly, in any gauge, at any tension, in any set of conditions) is as soft as a natural gut then: the data is flawed or you don't know how to interpret it

Seeing that TW Prof is one sharp cat, I'm going to go with the second.
 
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