Does Nat. Gut becomes less stiff at higher tension??

[ricardo]

The following data are from TW String Performance DB.
It shows that in general, NG becomes less stiff at higher tensions (> 61 lbs).
It is softest @40lbs, stiffest @51lbs, and becomes less stiff @62lbs.

In your actual hitting experience, did you feel that NG is less stiff at higher tensions (>61 lbs).
If it does, what benefits does it give you at tensions over 61lbs?

Thanks in advance..

Note:
I string NG (P. Classic 17g) at a max of 53lbs.
I hesitate to go higher because it might break.


1 Babolat Tonic + Natural Gut 16 Low (40 lbs) 96.0
2 Babolat Tonic + Natural Gut 16 Medium (51 lbs) 103.4
3 Babolat Tonic + Natural Gut 16 High (62 lbs) 101.7

4 Babolat VS Natural Team Gut 17 (1.25) Low (40 lbs) 92.6
5 Babolat VS Natural Team Gut 17 (1.25) Medium (51 lbs) 93.2
6 Babolat VS Natural Team Gut 17 (1.25) High (62 lbs) 100.6

7 Babolat VS Natural ThermoGut 16 Touch Low (40 lbs) 98.9
8 Babolat VS Natural ThermoGut 16 Touch Medium (51 lbs) 106.3
9 Babolat VS Natural ThermoGut 16 Touch High (62 lbs) 101.2

10 Klip Armour Pro 16/1.30 Low (40 lbs) 109.7
11 Klip Armour Pro 16/1.30 Medium (51 lbs) 112.0
12 Klip Armour Pro 16/1.30 High (62 lbs) 106.3

13 Klip Legend 16 Uncoated Low (40 lbs) 101.7
14 Klip Legend 16 Uncoated Medium (51 lbs) 105.2
15 Klip Legend 16 Uncoated High (62 lbs) 104.0

16 Pacific Classic Natural Gut 16 Low (40 lbs) 95.4
17 Pacific Classic Natural Gut 16 Medium (51 lbs) 100.0
18 Pacific Classic Natural Gut 16 High (62 lbs) 90.9

19 Pacific Prime Natural Gut 16 Low (40 lbs) 85.2
20 Pacific Prime Natural Gut 16 Medium (51 lbs) 88.6
21 Pacific Prime Natural Gut 16 High (62 lbs) 88.6

22 Pacific Prime Natural Gut 16L Low (40 lbs) 90.9
23 Pacific Prime Natural Gut 16L Medium (51 lbs) 98.9
24 Pacific Prime Natural Gut 16L High (62 lbs) 96.0

25 Pacific Tough Gut 16 Low (40 lbs) 112.0
26 Pacific Tough Gut 16 Medium (51 lbs) 115.4
27 Pacific Tough Gut 16 High (62 lbs) 110.3

28 Pacific Tough Gut 16L Low (40 lbs) 96.0
29 Pacific Tough Gut 16L Medium (51 lbs) 104.0
30 Pacific Tough Gut 16L High (62 lbs) 98.9

31 Wilson Natural Gut 16 Low (40 lbs) 99.4
32 Wilson Natural Gut 16 Medium (51 lbs) 97.7
33 Wilson Natural Gut 16 High (62 lbs) 98.3

34 Wilson Natural Gut 17 Low (40 lbs) 89.2
35 Wilson Natural Gut 17 Medium (51 lbs) 83.4
36 Wilson Natural Gut 17 High (62 lbs) 94.9

 

[ultradr]

I don't think 51 lbs feels stiffer than 62 lbs. I personally don't feel like it.

I'm not sure how stiffness is measured in the test but my guess is that they
use single impact. In other words, the force F is fixed. In real life, you experience
varoius impacts, F.

This is how single avergaed metric can mislead the nature of things.
I use 63+ lbs on VS or Tonic+. I feel like it is stiffer than multies and some
some mono's on low - medium impact but beautifully resilient on heavy
impact, which I still don't think a synthetic can reproduce.

Also, it measures a metric at one moment. In real life, the impact is applied
for hours of playing time. Over the course of the entire string life, I do feel
61 lbs is definitely stiffer than 51 lbs (for most of impact sizes).

If somebody can produce a 2D graph of stiffness at y axis with size of impact,
F, on x axis. And produce these graphs over some lifespan of the string bed.
That would be 3D graph. It might tell better story.
But would it be worth to do it? I can certainly feel the nature of strings myself.

 

[ricardo]

I'm not sure how stiffness is measured in the test but my guess is that they
use single impact. In other words, the force F is fixed. In real life, you experience
varoius impacts, F.

TW String DB test are done as follows:

String Testing Procedure

1. Tests: twelve dynamic impact tests are performed on each string:

62 lbs reference tension slow speed impact
62 lbs reference tension medium speed impact
62 lbs reference tension fast speed impact
Prestretched 62 lbs reference tension slow speed impact
Prestretched 62 lbs reference tension medium speed impact
Prestretched 62 lbs reference tension fast speed impact
51 lbs reference tension slow speed impact
51 lbs reference tension medium speed impact
51 lbs reference tension fast speed impact
40 lbs reference tension slow speed impact
40 lbs reference tension medium speed impact
40 lbs reference tension fast speed impact​

2. String length: Cut new test string of length = 330 mm.
3. Tension: string tensioned to reference tension.
4. Elongation: measure immediately after tensioning.
5. Static wait period: wait 60 seconds and record tension.
6. Stabilization impacts: 20 high speed (equal to force on a string during a 120 mph serve) impacts on string. Record tension after.
7. Test impacts: slow, medium, fast speed impacts in that order. Tensions, duration, forces, deflections, velocities all recorded.
8. Prestretch: After tests all performed on 62 lb string, raise tension back up to 62 and perform steps 5, 6, and 7 again.
9. Repeat: Repeat 2-7 for reference tensions of 51 and 40 pounds (prestretch not performed on these tensions).

Stiffness
What is it? This is the key measurement. Most others depend on this. Stiffness is measured dynamically during the impact. The measurement indicates the force necessary to stretch the string 1 inch during impact.

 

[ultradr]

Then it means they averaged 3 numbers. My feeling is that it gets stiffer
with low to medium impacts. But I know my human sense is not all that accurate.

 

[Fintft]

Then it means they averaged 3 numbers. My feeling is that it gets stiffer
with low to medium impacts. But I know my human sense is not all that accurate.

I also feel that the higher the tension, the stiffer natural gut (VS Team 17 mainly) feels...