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1. I don't quite get how a racket is supposed to be "faster than any human swing" and how manufacturing a flexible shaft will allow for this? Wouldn't a durable stiff shaft be more helpful for that goal?

2. Originally Posted by kirbosmash
And wow you all focused on "gifted in physics." I was only trying to get your attention. Maybe I got it too much.
Haha, maybe many of us are very envious of you having "the gift", so we all started bashing your statements for fun.

Just kidding, you are alright.

3. Originally Posted by kirbosmash
And wow you all focused on "gifted in physics." I was only trying to get your attention. Maybe I got it too much.
We are not intentionally focusing on your "gifts for physics", there's just nothing else to focus on . Please, don't think of us as mean .

4. In order for companies to truly make rackets more powerful, they would have to find a way to make it flexible, so flexible that its' faster than any human swing. That material is too futuristic- not only must it be ultra elastic it must also be ultra durable - this is star trek and stargate material.
This is not necesarilly true either, having a material that is flexible, in a sense would be a whip. The problem with that is it would be imposible to be consistant, having to time every shot perfectly. There are reasons why people who like to smash, use stiff rackets. The racket is a mere extension of the body, when you swing, you swing with all of your body's inertia, thats where the power comes from, weight transfer, which then is amplified by the shoulder rotation, which then is amplified by the rist, and finally by the racket itself. You could increase the power simply by making the racket longer, increasing the levrage.

5. You could increase the "power" simply by making the racket longer, increasing the levrage.
That's true because work = force x distance..

Also, Momentum = Mass x ( velocity which is [Distance travelled / time])
The mass and the length of the racquet can both affect the "power", given that the swing speed remains constant.. and also lets say, if racquet A and B have constant "x" mass and "y" "length" ( in general ) and if racquet B has a more aerodynamic frame and shaft profile. The aerodynamic"er" frame will reduce the time taken to swing the racquet if the distance swung remains constant for all racquets, therefore also the "power" will increase as the velocity value in general will also increase.

"Mass" is just too vague as well as Kirbosmash mentionned, it should be taken in context of "sweetspot" or the balance point/centre of gravity from the pivot, and also the total mass of the racquet.
So simply, the balance point can also affect the time taken to swing. Lower bp ( or just lower "mass" ) will give faster swing speed ( there is a limit to this swing speed ). Higher bp ( head-heavy ) racquets will have greater value of "mass" and may take more time to swing the racquet a constant distance, but if the weilder can swing the racquet fast enough ( lets say, at the same speed as the head-light racquet), the head-heavy racquet ( and also heavy in general ) can produce more "power" than a "light" racquet if the racquet length ( most importantly ), strings, etc remain constant.

The stiffness of the material used in the racquet will also affect the "power" and durability. The flexibility/stiffness can change the output "power", but it also depends upon the user as explained by Loopy:

So pretty much, there can only be "powerful racquets" if everyone are physically the same, which isn't the case. Basing our racquet purchases on the racquet's marketed "power" is just non-sense.

6. What jhirata says is completly true, rackets don't swing themselves. The power is in the wielder, not the racket.

7. Originally Posted by jhirata
That's true because work = force x distance..

physically the same, which isn't the case. Basing our racquet purchases on the racquet's marketed "power" is just non-sense.

we agree on something jhirata.

8. Originally Posted by chewablemorphin
This is not necesarilly true either, having a material that is flexible, in a sense would be a whip. The problem with that is it would be imposible to be consistant, having to time every shot perfectly. There are reasons why people who like to smash, use stiff rackets. The racket is a mere extension of the body, when you swing, you swing with all of your body's inertia, thats where the power comes from, weight transfer, which then is amplified by the shoulder rotation, which then is amplified by the rist, and finally by the racket itself. You could increase the power simply by making the racket longer, increasing the levrage.

Interesting concept with the leverage idea - that physically should work. When I say flexible, I mean that this material is completely out of our league - say, 75 years in the making - it catches the bird for a split seconds then rebounds it faster than any swing - it basically makes "cheating" rackets.

9. The only comment I have is the above applies fundamental physics which works on rigid systems. Assuming rigid systems helps the students to understand/approximate what they learn as related to what they observe in the general world.

The problem is the world and definitely our racket system is not rigid. The strings stretches, the shaft and racket head flexes, and even the grip/body system of the player introduces flex.

Jhirata: the "work done" calculation is wrongly applied. An increase in length of the racket shaft at the same angular velocity increases the "speed" of the racket head. And Taneepak's version of physics is indeed mindblowing at times.

10. Originally Posted by kirbosmash
...First off, what is the scientific meaning of power? Answer: Momentum. By the law of conservation of momentum, the momentum of the racquet is completely transferred to the birdie....

Power and momentum are two different things in physics. You've given the correct definition of momentum. Power is defined to be the rate of work done--that is, power equals force times distance divided by time. It's easy to look up these words in wikipedia or other web sites.

Only a part of the racquet's momentum is transferred to the shuttlecock. If the momentum were completely transferred, that would mean the racquet would stop moving at the instant it hit the birdie. (Look up "elastic" versus "inelastic" collisions if you want to learn a little more physics here!)

Thanks for posting your article, it's a good way to get an interesting discussion going!

11. Don't know if anyone is still viewing this thread, but since I just read it, I'll give my two-cents worth. Kirbosmash is not wrong, but he only attempted to address half the problem. The first problem is momentum, while the second problem is momentum transfer. To maximize power, you need to maximize both.

As we know, momentum is proportional to mass and speed. If you want to raise mass only, try use a tennis racket, and you'll find that your birdie can't go very far. If you raise the speed only, try the lightest racket, but your birdie can't go very far either. As racket mass (or mass moment of inertia to be more precise) goes up, your swing speed can only go down, but you may still have net momentum gain, as long as your swing speed does not reduce too drastically. If you make a plot of mass moment of inertia (y-axis) vs. momentum (x-axis) for yourself (which depends on how well you can maintain racket speed as the mass moment of inertia goes up), you'll find that your curve peaks at some point. This peak tells you the optimum moment of inertia for you (which is personal), and it helps you decide your own optimum racket.

Assuming now that you have chosen a racket that allows you to generate your maximum momentum (which would probably still a lot lower than that of Mr. Tan Boon Heong), now the next question is, how well can you transfer all this momentum to the birdie. Instead of a simple kinematic problem, we are now dealing with a more complicated structural dynamic problem. This is where shaft stiffness and string tension matter. Your swing speed excites a series of frequency responses, and only part of these responses are transferred to the birdie. Here's the hint: birdie (cork) has a natural frequency, and the key to maximize momentum transfer is to maximize the excitation at that particular frequency.

I'm gonna stop right here, as I'll have to start charging consultation fee from here on :-)

12. indeed an expensive powerful racket might only help you perform few % better then a cheaper racket, the badminton player skill and strength is the key point of the overall performance; LinDan can beat you easily with a USD \$40 racket eventhough you use a USD \$400 racket. . .

13. I am a no brainer and by now after reading the full 2 pages of this thread, i am suffocated and drown in physics, which i failed miserably in high school
To me, i like to live in a simple world and makes complicated thing look simple. Since i have no "gift of physics" . i see the whole thing this way:

Badminton = (racket + string + grip) + (PEOPLE + SKILLS) (Of course there are shoes and birdie and your shirt pants undies, etc.)

Based on my SIMPLE equation above,

For a beginner ,
You should concentrate only on PEOPLE + SKILLS. Train with the proper footwork, how you hold the racket, how you swing how you smash, etc etc FIRST. Forget about racket + String + Grip and all the fancy science behind that, you do not need them, not yet.

Now, suppose you are Lin Dan,

By then, you can take out PEOPLE + SKILLS as they are already reaching a very sustainable high level consistently. So, now you can look at Racket + String + Grip to ENHANCE (Note the word ENHANCE) your overall badminton play and enjoyment.

on the other hand, if you are Lin Dan,
since your PEOPLE + SKILLS is almost equal to infinity (max), you can substitute racket + Grip + String = 0 (i.e cheap USD20 rackets, string, grip) and still thrash anyone with PEOPLE + SKILL = 0 (i.e no proper skill, wrong skills, etc.)

So is Racket + String + Grip important ? Yes, but NOT until you have got the PEOPLE + SKILLS, i.e proper foundation, the correct gripping of racket, the swing, the smash, the footwork etc.

OK enough of no brainer equation, time for me to hit the court now.

Cheers

14. Originally Posted by chewablemorphin
This is not necesarilly true either, having a material that is flexible, in a sense would be a whip. The problem with that is it would be imposible to be consistant, having to time every shot perfectly. There are reasons why people who like to smash, use stiff rackets. The racket is a mere extension of the body, when you swing, you swing with all of your body's inertia, thats where the power comes from, weight transfer, which then is amplified by the shoulder rotation, which then is amplified by the rist, and finally by the racket itself. You could increase the power simply by making the racket longer, increasing the levrage.

Interesting point you made on highlighted above.

Now that you mentioned it, does it mean that in general a player with a longer arm (such as a tall player) would be able to execute a more powerful smash, given all other conditions are similar?

15. It is misleading to focus on sheer racquet power. What is more important is to strive for a racquet with effective power for that particular player. A very long racquet with its extreme swing weight is not an effective power racquet because it is only powerful in very few situations.
It may be interesting to note that a racquet with effective power is also a highly controllable racquet.
A racquet derives its power from the youngs modulus of its materials-and this has nothing to do with the stiffness of the shaft-and from slim dimensions of the racquet frame in all the directions of its swing. Materials with very high Youngs modulus are extraordinarily stiff as they are the end product of 3,000 degrees C. They are very stiff but more brittle. It is these qualities that will allow the racquet to be designed to have slim frame dimensions, which will increase its swing speed (note, not swing weight) from reduced air resistance.
However, you can also design a racquet with equal power, but not the same degree of effective power, with lower Youngs modulus materials like those graphite that come out from 1,500 degrees to 2,000 degress C. To do this you need to have thicker frame dimensions to offset that "jelly-like" distortion of the frame from power hits. This however comes at a cost, and that is it will have reduced swing or hand speed because its thicker frame dimensions wil meet greater air resistance. But you will get a stronger racquet that can withstand clashes better than the more expensive higher Youngs modulus racquet.
With very high Youngs modulus materials you also eliminate any "jelly-like" feeling with no loss of fast hand speed, which will provide you with excellent control-the shuttle will zero in like a laser from any shot and not wonder off sometimes unpredictably.
There are a few simple methods of testing a racquet for these qualities before you buy the racquet.

16. There is only one way to test this. You have to test every single variable.

You need:

3 Rackets: All Extra Stiff - 1 Head Heavy, 1 Even, 1 Head Light
3 Rackets: All Stiff - 1 Head Heavy, 1 Even, 1 Head Light
3 Rackets: All Medium - 1 Head Heavy, 1 Even, 1 Head Light

This way you can test every variable of the racket. You can test:

a) Varied stiffness in ALL head heavy rackets
b) Varied stiffness in ALL even rackets
c) Varied stiffness in ALL head light rackets

Here we have tested how the stiffness of the shaft is affected by the balance

d) Extra stiff in ALL varied balance
e) Stiff in ALL varied balance
f) Medium in ALL Varied balance

Here we have tested how balance is affected by the balance.

These 2 may sound the same but they are not as the first you are testing one stiffness with different balance i.e 3 Head heavy 1 stiffness. The second is testing one balance with different stiffness i.e. 3 Stiff 1 balance. For all of these rackets you need to use the most basic of swings at an average tension.

Then you move onto strings. You now need to string one type of racket with every different string. To make things average out take a stiff shaft with even balance as its the mid point.

Once you have done that you then need to combine the lot. String every single different racket with every single different string to find which is the best combination.

That isn't even including physical variables i.e. who is using the racket.

Basically the whole idea is a bit much as badminton companies have physicists working on this stuff who can use their knowledge and computer programs to test their theories.

Why do you think there is rarely an extra stiff head light racket. Its because you would get no power at all and would be 100% defense.

The best option to test this theory is to pick just one variable, the racket being the obvious one but you need to find them with similar technology.

17. Originally Posted by Smithy88
There is only one way to test this. You have to test every single variable.

You need:

3 Rackets: All Extra Stiff - 1 Head Heavy, 1 Even, 1 Head Light
3 Rackets: All Stiff - 1 Head Heavy, 1 Even, 1 Head Light
3 Rackets: All Medium - 1 Head Heavy, 1 Even, 1 Head Light

This way you can test every variable of the racket. You can test:

a) Varied stiffness in ALL head heavy rackets
b) Varied stiffness in ALL even rackets
c) Varied stiffness in ALL head light rackets

Here we have tested how the stiffness of the shaft is affected by the balance

d) Extra stiff in ALL varied balance
e) Stiff in ALL varied balance
f) Medium in ALL Varied balance

Here we have tested how balance is affected by the balance.

These 2 may sound the same but they are not as the first you are testing one stiffness with different balance i.e 3 Head heavy 1 stiffness. The second is testing one balance with different stiffness i.e. 3 Stiff 1 balance. For all of these rackets you need to use the most basic of swings at an average tension.

Then you move onto strings. You now need to string one type of racket with every different string. To make things average out take a stiff shaft with even balance as its the mid point.

Once you have done that you then need to combine the lot. String every single different racket with every single different string to find which is the best combination.

That isn't even including physical variables i.e. who is using the racket.

Basically the whole idea is a bit much as badminton companies have physicists working on this stuff who can use their knowledge and computer programs to test their theories.

Why do you think there is rarely an extra stiff head light racket. Its because you would get no power at all and would be 100% defense.

The best option to test this theory is to pick just one variable, the racket being the obvious one but you need to find them with similar technology.
You are right on the scarcity of extra stiff head light racquet and NS9900 is one of them. Mine had a bp of 275mm ! However, the power generated is still pretty decent PROVIDED you can compensate with a fast swing.

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