Stringbed frequency to monitor string tension

[visor]

i have to disagree. the head will exand and contract under heat/cold and result in a bigger/smaller oval.

You're correct.

Coefficient of linear thermal expansion of pure graphite is 4.4 x 10^-6 in/in°F, and for aluminum is 12.3.

So for 15C change is 27F change. Plug in 27 in for frame circumference.
Results in 0.0032 in, or 0.081 mm.
Somehow that is very negligible.

[kwun]

You're correct.

Coefficient of linear thermal expansion of pure graphite is 4.4 x 10^-6 in/in°F, and for aluminum is 12.3.

So for 15C change is 27F change. Plug in 27 in for frame circumference.
Results in 0.0032 in, or 0.081 mm.
Somehow that is very negligible.

hehe. so there IS!!

i agree though, it is negligible.

but how do we explain your observation then?

[cobalt]

You're correct.

Coefficient of linear thermal expansion of pure graphite is 4.4 x 10^-6 in/in°F, and for aluminum is 12.3.

So for 15C change is 27F change. Plug in 27 in for frame circumference.
Results in 0.0032 in, or 0.081 mm.
Somehow that is very negligible.

Have you tried it? Did you measure it with your electron microscope? Did you leave your favourite racquet out on the cold, cold mountain for a day, then slow-roasted it over the barbeque, and measured the difference?

If everything in the real world could be explained through physics and theorems and stuff, we would all be visor than we are...

[visor]

Lol! Lemme check the coefficient for cobalt and see if I need to subject it to extreme temps...

[visor]

hehe. so there IS!!

i agree though, it is negligible.

but how do we explain your observation then?

I don't know... I'll check vs850 tonite.

[kwun]

2 rackets. NS9000, AT900P

both strung with NBG98 @ 23.8/26lbs

0hr:

NS: 1212.3Hz
AT: 1193.4Hz

3 hrs:

NS: 1188.4Hz
AT: 1162.1Hz

17hrs:

NS: 1177.0Hz
AT: 1150.4Hz

[visor]

VS850 at 24 lb on SW30 from 9 months ago, rarely played

1027 Hz at 20C
1023 Hz at 5C
1027 Hz at 20C again

So, there is a trend. Tensions fall off a tad when colder. But this is only like 0.1 lb and the string material hardening with colder temp is probably more significant in causing a harder brittle feel in the cold.

Still would be interesting to see what happens in Asia going from 20C to 35C. Anyone?

[ucantseeme]

SW35 with BG80 @29lbs: 1197 Hz, strung @Yonex German Open with EsPro, measurement at 6-8 hours after stringjob.

Today, at 1123 Hz. String and tension feel comfortable, powerful and are superb IMO.

[blableblibloblu]

Looking at a few frequencies provided and comparing, it seems to me like Victor racquets tend to have a lower frequency at the same tension as lets say Yonex. Could have to do with the fact that they don't fill the racquets with foam.

[visor]

Looking at a few frequencies provided and comparing, it seems to me like Victor racquets tend to have a lower frequency at the same tension as lets say Yonex. Could have to do with the fact that they don't fill the racquets with foam.

Hmmm... as I understand, the foam is placed inside the T joint, not throughout the whole frame, right? I don't think I've ever seen any foam in the frame in any of the broken rackets post mortem photos.

[blableblibloblu]

Hmmm... as I understand, the foam is placed inside the T joint, not throughout the whole frame, right? I don't think I've ever seen any foam in the frame in any of the broken rackets post mortem photos.

http://bbs.badmintoncn.com/thread-196139-1-1.html
not quite sure exactly where they put it since I haven't looked at the whole thread and haven't translated what he says. Doesn't seem to be in the whole frame though. Could still have an impact on frequency though, I think.