Stiffness rating: Stringing changes it?

[10SDad]

I just purchased a set of new racquets that were listed online as having a stiffness rating of 63. However, the flex number stamped on the frames I received is 67. I asked the vendor why the difference. The response I got was that the specs they publish online reflect a strung racquet. Does stringing change (i.e.: reduce) the overall stiffness/flex of a racquet? And by as much as four points? I understand the changes to SW and overall weight when adding string, but a reduction in stiffness/flex is a new one for me. I was counting on the 63.

What say you experienced experts?

 

[Ripper]

Well, I don't consider myself an expert, but I can think logically. First of all, I'm pretty sure that the stiffness ratings done by TW come from unstrung raquets. Btw, they have a forum for asking them questions. So, you could ask them directly. Second, my guess would be that a strung raquet would give a higher stifness reading than the same raquet unstrung. And I would guess that the higher the string tension, the higher the reading... Hey, but I'm just guessing here...

 

[NoBadMojo]

The frame stiffness does indeed become less after stringing, but 4 points is A LOT! 1 or possibly 2 would be acceptable. TW specs their frames strung, not unstrung. if your target is 63 and TW or some other reliable source tested the stiffness at 63, then you're in like flint no?

 

[cadfael_tex]

Frame stiffness is related to the frame and as such does not change with strings. The strings have a stiffness value of their own -from tension and material. These two values interact to give a specific feel to a player. Changing string tension or type does not change the construction of the racquet and thus the stiffness but does give a different overall value for the stiffness of the combination.

 

[NoBadMojo]

that's not what the question is. the question pertains to stiffness unstrung vs stiffness strung