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artdrucker
08-20-2008, 12:52 AM
It's really a small detail but I am curious. Does anyone know what is the real score for k90's stiffness index? Tennis.One and other sources say 66 but TW says 67.

BreakPoint
08-20-2008, 02:01 AM
It's neither, IMO. To me, it plays more like 63.

artdrucker
08-20-2008, 02:23 AM
It's neither, IMO. To me, it plays more like 63.

How interesting. That's also my opinion. These published indexes are not reliable measures.

jorel
08-20-2008, 04:49 AM
WIlson QC in general stinks.... also stiffness varies whether the frame is strung or unstrung

edberger
08-20-2008, 10:56 AM
I agree with BP...the K90 plays much more flexible than the published specs.

On a side note, does the balance feel much less HL than 9pts to anyone?

Murray_Maniac
08-20-2008, 01:00 PM
I agree with BP...the K90 plays much more flexible than the published specs.

On a side note, does the balance feel much less HL than 9pts to anyone?

Yea, but it doesnt feel too flexy. Probably 63 or 64. I didnt think it was any more than 9 points hl.

BreakPoint
08-20-2008, 02:07 PM
How interesting. That's also my opinion. These published indexes are not reliable measures.
It's more due to the way they measure the stiffness of a frame which takes account the stiffness of the throat more than the other parts of the frame. As a result, when you play with the entire frame, it could feel stiffer or more flexible than the specs indicate. A more open string pattern can also make the racquet feel less stiff.

In general, frames with stiff throats and flexy hoops will feel more flexible than their specs indicate. Another example is the PS 6.0 95, which is rated at 67 but plays more like 61/62.

nn
08-21-2008, 01:28 PM
yeah too me it is like 62 at max with good power..not too much like babolate but also add string to the mix

tennistiger
08-22-2008, 02:48 AM
Tennis Magazin Germany: RA=60

JediMindTrick
08-22-2008, 07:00 AM
The one that I played with felt stiff, stiffer than the nCode 95 which was 65, so 67 sounds about right.

NoBadMojo
08-22-2008, 07:10 AM
It's more due to the way they measure the stiffness of a frame which takes account the stiffness of the throat more than the other parts of the frame. As a result, when you play with the entire frame, it could feel stiffer or more flexible than the specs indicate. A more open string pattern can also make the racquet feel less stiff.

In general, frames with stiff throats and flexy hoops will feel more flexible than their specs indicate. Another example is the PS 6.0 95, which is rated at 67 but plays more like 61/62.

The rdc stiffness measurement is a very simple and accurate measurement of a racquets stiffness/flexibility. it measures the overall AVERAGE stiffness/flexibility of the racquet in total and is NOT the measurement at the throat.

I am happy to trust this measurement as it is accurate rather than believing a TW poster who may have a good sense of this or a horrible one

artdrucker
08-22-2008, 01:32 PM
Originally Posted by Anton yesterday:

quote

... the pressure is applied at one point, but what is being flexed is the entire length between the two fixing points that are resisting this force.

-*--------^---------*-

* = fixing point
^ = flexing force

unquote

I suspect that with this test the variation of hoop flexibilty in different racquets will not be proportionally reflected on the averages obtained.

Klatu Verata Necktie
08-22-2008, 01:39 PM
The high stiffness rating makes sense to me. I have played with various mid sized frames throughout my life and only the K90 has given me arm pain.

racquetfreak
08-22-2008, 01:57 PM
The rdc stiffness measurement is a very simple and accurate measurement of a racquets stiffness/flexibility. it measures the overall AVERAGE stiffness/flexibility of the racquet in total and is NOT the measurement at the throat.

I am happy to trust this measurement as it is accurate rather than believing a TW poster who may have a good sense of this or a horrible one

machine - objective....player - subjective. machine doesn't feel ball only parameters it's programmed to measure, players feel ball-racket interaction to form personal opinion.

TonyB
08-22-2008, 02:47 PM
I agree with BP...the K90 plays much more flexible than the published specs.

On a side note, does the balance feel much less HL than 9pts to anyone?



Yes, but it depends on the frame. A string job will reduce the K90's balance by 3 points. So if you start at 12, you get 9.

My racquet started at 10 (measured) and sits at 7 points HL now (measured).

Go ahead and measure yours and see what you get.

Bottle Rocket
08-22-2008, 06:46 PM
How interesting. That's also my opinion. These published indexes are not reliable measures.

Funny you should should say that, considering that the numbers published by TW actually are measurements. It's an average of multiple frames.

I agree with NBMJ and I also feel that the K90 feels exactly as stiff as the published specs.

NoBadMojo
08-22-2008, 07:03 PM
machine - objective....player - subjective. machine doesn't feel ball only parameters it's programmed to measure, players feel ball-racket interaction to form personal opinion.

right, but people can have a lousy sense of stiffness as i said, so i go with the rdc measurements which, with very few exceptions, match how stiff the racquet plays (but not the stringbed). i hit the k90...like almost all racquets, it is as the stiffness measurement indicates, and it is easy to tell especially when hitting it alongside with something w. a ra stiffness in the low 60's

hoosierbr
08-22-2008, 08:59 PM
I've hit both the N90 and K90 and found the K90 to be about what the specs indicate, stiffness included. Maybe more around 64/65. The biggest difference I found from the N90 was that anything hit out of the sweetspot was a lot less jarring. The N90 was some kind of beast on mishits, way too stiff for my wrists and elbows.

The K90 is still an advanced racquet that very few could use in a match successfully. I'm not one of them!

mraznman
08-22-2008, 11:03 PM
The high stiffness rating makes sense to me. I have played with various mid sized frames throughout my life and only the K90 has given me arm pain.

prob cuz of the weight not the stiffness?

Klatu Verata Necktie
08-23-2008, 05:48 AM
prob cuz of the weight not the stiffness?

All my frames are 12+ ounces, so I don't think that's the case.