Racquet Stiffness and You

Many racquet manufacturers include frame stiffness in their specifications that are viewed by the consumer. What exactly does that number mean to you?

Well, very simply, stiffer racquets will provide a little more power because the racquet is not loosing the bending energy, and a less stiff racquet may be a little more comfortable.

As a player there is very little you can do to decrease the stiffness other than bashing the racquet into the court then there is no issue!

However, your racquet technician can make your very own racquet feel “softer”! There is a little used characteristic called “effective stiffness” that I calculate for every racquet I do. I am not going into the formula for that stiffness here but if you go for a lower string bed stiffness it will, obviously, create a more flexible “feeling” unit.

So, if you have a racquet with a stiffness of 70 (RDC) and a string bed stiffness of 65 (RDC) you have an effective stiffness of 32.31 (which is pretty high). Now, if that is perfect for you it can be replicated from racquet to racquet. If you know the racquet stiffness you can arrive at the correct string bed stiffness to yield the desired effective stiffness.

Try it!

Posted on February 16, 2011, in Racquets and tagged , , , , . Bookmark the permalink. 6 Comments.

  1. John,

    Interesting. I am not familiar with the “effective stiffness” term. Thank you for teaching me something! We know that frame stiffness is the one variable that can not be altered through racquet modification. For those who are using stiff frames and suffering from elbow issues, assuming all other specs are reasonable, have you found that lowering the effective stiffness can be a solution?

    Two days ago I had a customer approach me with a Prince Hybrid Hornet. (I think the RA on that stick is 72) I added weight low on the racquet bringing the total strung weight to 11.6oz and a 1.5 pt HL balance. She was using Gamma TNT in the low 60’s. I restrung with WeissCANNON Explosiv! (a premium multi) in the low 50’s. Now wondering if I might have wanted to go even lower. Because of the stiffness of the frame, I am skeptical if the modifications made will help her elbow issues. However, I guess I did lower the effective stiffness. Time will tell but I am curious to know your thoughts if you have a moment.

  2. John, lowering the string bed stiffness was the way to go but without knowing the string bed stiffness number it is difficult to calculate the effective stiffness. However, it if works just continue using the same tension. If the effective stiffness is satisfactory the string material will be less of a factor.

  3. Given what you have stated about string material, would a copoly strung at 39 lbs be healthier than a multi at 52? Copolys play well at very low tensions. Thanks for sharing your thoughts with us via this blog!

  4. John, a co-poly at 39 can be “healthier” than a multi at 52. You are correct that polyester based strings are best at lower tensions, plus they are going to loose string bed stiffness pretty quickly. Higher elongation strings, like multifilaments, can produce higher string bed stiffness than polyester based strings, but that is another story for another time!

  5. hi, i have a yonex rdis 300 that has stiffness of 65, and i have a stringbed stiffness of 57.. would that be a good match?

    • That would have an effective stiffness of 30.36 which is a very nice, easy to use, stiffness. Of course a lot depends on how you want your racquet to “feel” but you are at a good point now, I think. BTW, what device are you using to test for racquet and string bed stiffness?

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