2003 Yonex rackets measurements

**bigredlemon** · 12-01-2003, 10:41 PM

Originally posted by cooler
I can also tell you how to experience real life dynamic stiffness but i doubt kwun would let me elaborate in BF

Don't take comments on the limitations of your measurements too personally.

**cooler** · 12-02-2003, 12:55 AM

This is part three of the 2003 (yonex) racket measurment focused on moment or the twisting force needed to put the racket into motion from the rest position. It doesn’t reflect perfectly the amount of totally energy to fully swing the racket but the relationship between moment to angular momentum should be reasonably close.

Again, the result presented is referenced to the 3U cab20m. Less than 1 mean the racket take less effort to move it than a 3U cab 20m. Relative moment greater than 1 means it would take more effort to move it than a 3U cab20m.

I’m sure BF members could draw many conclusion from these data.

**Neil Nicholls** · 12-02-2003, 03:21 AM

Originally posted by cooler
The old fashion way, I bend them

I'm sure several of us would still like to know how you measured the stiffness.
i.e. what equipment etc. If you clamped the handle in something did you clamp it right at the butt, in the middle, by the cone. Some of us just need to know

Also, when you normalise results for different length racquets, are you using the total length of the racquet, or just the length of the shaft, or shaft+head ?

**bigredlemon** · 12-02-2003, 10:28 AM

the definition of relative movement is vague. How did you measure this?

Since there is no static force against angular movement, the value for every racquet should be about 0. (1/infinity to be exact.)

**cooler** · 12-02-2003, 12:10 PM

Originally posted by bigredlemon
the definition of relative movement is vague. How did you measure this?

Since there is no static force against angular movement, the value for every racquet should be about 0. (1/infinity to be exact.)

It's obvious you are too quick trying to be overly precise and critical with my data while you haven't understood the objective of the matter.

The (Part 3) data presented relates to relative moment, NOT relative movement. How it was calculated? check kwun post not too far up from here.

http://www.badmintonforum.com/vb/sho...0&pagenumber=4

Moment does not necessarily has to be associated with movement or motion. For example, it's like Arnold Schwarzenegger twisting your arm behind your back. You feel pain but you ain't moving. Of course Arnold can apply lock-arm force + some additional moment (N-m) and you would be flying somersaut and experiencing lots of angular movement or momentum.

(hasta la vista, baby)

***kwun*** · 12-02-2003, 12:20 PM

agree with cooler. there can be lots of interacting forces / moments in a static system.

BRL, time to go dig out those high school textbooks...

**cooler** · 12-02-2003, 01:06 PM

Originally posted by Neil Nicholls
I'm sure several of us would still like to know how you measured the stiffness.
i.e. what equipment etc. If you clamped the handle in something did you clamp it right at the butt, in the middle, by the cone. Some of us just need to know

Also, when you normalise results for different length racquets, are you using the total length of the racquet, or just the length of the shaft, or shaft+head ?

Neil, I clamped the handle, not the cone because some shaft flexing does occur inside the cone. I normalized it to each racket total length.