# Thread: Why do people use a higher tension and get more power?

1. Originally Posted by jerby
Whatever quasi-phyisics you unleash on the subject hardly matters, you should just try and see what your own preferred tension is, what could be easier? All theories on "hang time" and "imparted kinetic energy" seem a little vague to me.
It matters to people who understand and love physics and like to discuss about what happens when the racket hits the shuttle in their favourite hobby. Everyone has a knack/intuition for understanding something. For some may be cooking, or economics, or driving, or interpersonal behaviour. For me, it's music and physics. It's just too bad that I/we can't explain it better for some of you...

2. Originally Posted by Trmun
Could someone explain why you lose power with higher tension in 1 sentence? Shouldn't the deformation of the strings be reduced the higher the tension, thus meaning less power being wasted, thus meaning more power being returned into the shuttle? Apperantly I'm missing something here
Well, Okay, I'm taking a stab at this whole physics discussion anyway.

And I'm doing by stating that the "conservation of energy"-angle is pointless.
We all now the concept, which is basically newtons third law applied to a collision. Now the easiest concept of a collision is an elastic collision, where we can state there is no energy lost and nothing is deformed (the deformation impulse is equal and opposite to the restition impulse, like the textbook says ) The perfect example of this being two billard balls, or a marble bouncing on cement. Notable traits of these types of collisions are the short contact time, and small deformations.
However, a racket striking a shuttle is not a perfectly elastic collision, a lot of sound is produced and both objects deform a bit.
So, physically speaking we first have to determine whether the coefficient of restitution (how inelastic is the collision, how much energy is lost?) actually changes when we alter the tension of the racket.
And finally, when we note that the CoR is determined by the speeds of both objects before and after impact we have to factor in actual skill of the player (swingspeed).
So, we have two variables to solve 1 one, making this whole thing pretty unsolvable, vague and open to interpretation.
All this is basic bachelor Dynamics, but tricky to apply to such a multi-facet example. Especially if you want to get a realistic and helpfull answer

Anyways, back to the real world. By your logic, you could just as easily state that because the string deformation is reduced at higher tensions there is less time to transfer the 'power' to the shuttle, thus losing power.
It's just not that simple.

3. Originally Posted by Trmun
Could someone explain why you lose power with higher tension in 1 sentence? Shouldn't the deformation of the strings be reduced the higher the tension, thus meaning less power being wasted, thus meaning more power being returned into the shuttle? Apperantly I'm missing something here
It would be a very looooong run-on sentence!!

You should understand that string deformation IS necessary and required (and to some degree shaft flexion) to first store the kinetic energy from the bird upon landing on the stringbed, and then most importantly to rebound and release all that energy back onto the bird before it has a chance to leave the stringbed.

Think about it this way. Compare that with using as strings very stiff steel wires that have very little elasticity. If you imagine a slow motion of the racket hitting the bird, you will see that there will be much less string deformation and the bird will bounce off the stringbed almost instantly. Very little stored energy and very little energy released back onto the bird, also partly because contact time was so much shorter. It doesn't matter if the swing is really fast or powerful, because the bird is no longer in physical contact with the strings.

4. Originally Posted by cooler
u r getting very warm In fact, the title itself of the thread is misleading which made most of the phyisics related explanation that came afterward 'off the mark'. It was wrongly assumed the title statement is a fact and then people go all out trying to explain it.

More reason of it not being a sticky
Originally Posted by visor
That's just hilarious!

So, because of the original misdirected question of the OP, henceforth all posts and discussions in this thread is useless?

Cooler, out of curiosity, did you read over wristworks and my discussion?
I understand, there have been tons of threads on this before and you may be getting jaded from previous arguments...
r u sure u r a physicist type? interested in physics and understanding of physics are 2 very diffferent things. The physicists that i know are careful with observation detail and draw backable conclusion or theory. what i see here is
1) poor observation and assumption( see above underlined words from my post and your post; see what the thread title said)
2) where are ur mathematical derivation? if not, where are your real life examples?

The presentations made here were almost analog to the presentation made in the 'Inconvenience Truth' movie where tibit of scientific data or observation is used to make one grandiose conclusion.

5. Originally Posted by jerby
Anyways, back to the real world. By your logic, you could just as easily state that because the string deformation is reduced at higher tensions there is less time to transfer the 'power' to the shuttle, thus losing power.
It's just not that simple.
You don't know how close you are to understanding it.

Forget about all the physics equations and Newton's laws and what not.

Yes, I'm trying to say that there is a certain optimal range of string deformation that is required and necessary. For a pro with faster more powerful swing, he'll need to have tighter stringbed to still remain in that optimal range, as compared to a beginner who'll need lower tension for the stringbed to bend and rebound.

This is all very similar to playing with stiff vs. flexy shafts. An optimal amount of shaft loading/bending and unloading/rebound is required and necessary. Given the same tension, a beginner would not be able to hit well with a stiff shaft, just as a pro would overwhelm a flexy shaft to the point of even breaking it.

In other words, string tension has to be matched to the swing speed/power. As simple as that.

6. Originally Posted by cooler
r u sure u r a physicist type? interested in physics and understanding of physics are 2 very diffferent things. The physicists that i know are careful with observation detail and draw backable conclusion or theory. what i see here is
1) poor observation and assumption( see above underlined words from my post and your post; see what the thread title said)
2) where are ur mathematical derivation? if not, where are your real life examples?

The presentations made here were almost analog to the presentation made in the 'Inconvenience Truth' movie where tibit of scientific data or observation is used to make one grandiose conclusion.
Hmmm....I don't know where to begin...

Oftentimes, life and the world is not amenable to scientific analysis.
For example, just because I can't put into equations what love is, doesn't mean it doesn't exist.

There are no mathematical equations for a stringbed hitting a shuttle.

The only way is to imagine a slow motion of it happening and imagine what would happen if certain variables are changed, eg. tension, swing speed. (It is called a thought experiment; no equations, no math, just intuition.) Well, that is, unless someone has already taken a high speed slow mo video of it already. Hmmm... let me take a look at the Arc Z video of their smash testing.

PS, Since you personally know some physicists, can you try asking them about this conundrum that we have? I'd like to know what their intuition tells them.

7. Originally Posted by visor
Hmmm....I don't know where to begin...

Oftentimes, life and the world is not amenable to scientific analysis.
For example, just because I can't put into equations what love is, doesn't mean it doesn't exist.

There are no mathematical equations for a stringbed hitting a shuttle.

The only way is to imagine a slow motion of it happening and imagine what would happen if certain variables are changed, eg. tension, swing speed. (It is called a thought experiment; no equations, no math, just intuition.) Well, that is, unless someone has already taken a high speed slow mo video of it already. Hmmm... let me take a look at the Arc Z video of their smash testing.

PS, Since you personally know some physicists, can you try asking them about this conundrum that we have? I'd like to know what their intuition tells them.
I consider your post #54, #56 and #57 to be like flunk test scores.

u said love can not be solved scientifically. Yes but no one is attempting to make conclusion about love using scientific reasoning. However, in this thread, many are using science and physics to showcase their points. To me, then u should back it up with the rigor of science that is required in any scientific claim.

PS. since u posted your PS afterward. I say, why ask when u can't comprehend the answer? btw, may i ask how qualify of physicists should i consult with? number of papers published? number of science degrees? or amount of dollar reseach grant received? Number of seats sat in science organization?

8. You know what?
Some people in this world are good at building up, then there are others who are only good at tearing down.

If you can't or don't want to try the thought experiment, then

I just don't think that this issue can be settled by mathematical dissertations and scientific analysis. Maybe, just maybe, if we have a high speed slow mo video of the critical time when the bird hits the stringbed until it leaves the stringbed.

9. Originally Posted by cooler
PS. since u posted your PS afterward. I say, why ask when u can't comprehend the answer? btw, may i ask how qualify of physicists should i consult with? number of papers published? number of science degrees? or amount of dollar reseach grant received? Number of seats sat in science organization?
Ummm... do you have this reversed? I'm not the one who is demanding that equations must be supplied, and Newton's laws must be posited, and scientific analysis must be observed... I believe that is you!

So why would you think that I would ask for degrees, papers, grants, positions? I just want to know what they think of it intuitively... as a thought experiment!

And what makes you think that I won't be able to understand their thoughts?

BTW, just out of curiosity, do you really understand what I'm saying about optimal stringbed deformation?

10. Originally Posted by visor
You know what?
Some people in this world are good at building up, then there are others who are only good at tearing down.

If you can't or don't want to try the thought experiment, then

I just don't think that this issue can be settled by mathematical dissertations and scientific analysis. Maybe, just maybe, if we have a high speed slow mo video of the critical time when the bird hits the stringbed until it leaves the stringbed.
1. LOL, say that to the building inspector when u r erecting a mickey mouse tower

2. what make u think i haven't thought about this subject before? u think i felt off a turnip truck yesterday and a light bulb came on?

3. what is your objective of this slow-mo video of the critical time when bird hits stringbed? what r u trying to measure?

11. Found a slow mo video here on the Arc Z intro site:

Skip the intro, goto "Speed test", then click the movie on the right.

1. My objective is to show the deformation in the stringbed. It is very necessary and critically important in the transfer of energy from bird to string on impact, then string to bird on rebound. Is that agreed?

2.. If so, then I postulate that there is a certain optimal deformation, not too little and not too much, that is best for max energy transfer. From the video, the stringbed appears to deform maximally about 1 inch back, then it rebounds and pushes the bird off. Agreed?

3. I would postulate that if the strings are too tight then the deformation would be less, maybe only 1/2 inch, and if too loose then deformation would be more, maybe 2 inches. Acceptable?

4. Conversely, we can say that if the swing power is not enough, then deformation would be less, maybe 1/2 inch, and if too powerful, the deformation would be more, maybe 2 inches. Follow?

5. Now comes the intuition part: what if 1 inch was the most optimal stretch or deformation for the best rebound? What if 1/2 inch is good, but still not yet even taxing the system yet? What if 2 inches is too much stress on the system, beyond optimal?

6. Think about 5 for a bit.
If agreed, then can you understand why I believe intuitively that in order to get the best power transfer, there is an optimal stringbed deformation that we should aim for. And that can be adjusted by string tension (and also shaft stiff/flex) according to how fast/powerful the person can swing his racket.

/thought experiment

12. So, cooler and all, what do you think?

13. I think that there is too much arguing going on over something that probably can't be proven either way.

Pure physicists would have a hard time dealing with this subject as they tend to deal more in the abstract than in real world conditions, engineers would tend to be able to apply physics to the real world better and in many cases engineers do NOT do so with the basis of science and math but on imperical data.

There are too many variables including swing speed, swing technique, racket flexibility, string composition and flexibility... etc. Composition of the string has a noticeable affect on it's performance, as we all know if you compared something like BG65 to BG66. Going back to the steel analogy, a braided cable is more flexible and stronger than a single strand of equal thickness.

If we're going to ignore all other aspects and focus purely on tension (keeping all other variables the same) then I will agree that there is a tension range in which you will have the maximum energy transfer but in reality it's lower than most of us want to play with as we lose controllability. Look at all models of elastic behavoir such as a trampoline, the bow (as in bow and arrow)... etc. They all depend on the transfer of energy from one object to another.

There is one thing to keep in mind, the stronger the tension in the string the higher the theoretical power it can transfer if you can generate the swing speeds to still bend the strings in order to transfer that power.

I make mention of the bow and arrow earlier and will use it as an example. A bow that a child or woman can bend will be more flexible than one a man can and therefore will generate less power. But if you give the bow that a man can bend to a woman then she cannot pull it back far enough to put the bow into enough tension that it has the same power as a bow designed for her. Therefore we do need to match the tension on the strings to the swing speed of the player in order to maximize the transfer of energy.

Springs are another example of stored energy and come in various sizes, compositions, lengths, thicknesses... etc. just like our strings do and offer different levels of stored energy.

These discussions should really center more around conservation of energy or conservation of momentum than any other types of physics theories so in that way I agree with jerby. Keep in mind that we're talking both potential and kinetic energy here (as in my spring example).

This is all my opinion of course and any one is more than welcome to dispute or discuss them.

14. Originally Posted by druss
I think that there is too much arguing going on over something that probably can't be proven either way.

Pure physicists would have a hard time dealing with this subject as they tend to deal more in the abstract than in real world conditions, engineers would tend to be able to apply physics to the real world better and in many cases engineers do NOT do so with the basis of science and math but on imperical data.

There are too many variables including swing speed, swing technique, racket flexibility, string composition and flexibility... etc. Composition of the string has a noticeable affect on it's performance, as we all know if you compared something like BG65 to BG66. Going back to the steel analogy, a braided cable is more flexible and stronger than a single strand of equal thickness.
From the title of the OP's thread, we're really only considering tension and swing speed. We want to understand the relationship between the two, so obviously we have to keep all other factors exactly the same. Ceteris paribus. Obviously it would be overly complex to include other factors like string thickness/material, frame/shaft stiffness/material, ambient temperature, type of shuttle, etc. I'll let others study about them if they want to.

If we're going to ignore all other aspects and focus purely on tension (keeping all other variables the same) then I will agree that there is a tension range in which you will have the maximum energy transfer but in reality it's lower than most of us want to play with as we lose controllability. Look at all models of elastic behavoir such as a trampoline, the bow (as in bow and arrow)... etc. They all depend on the transfer of energy from one object to another.
Good point. As was mentioned by Dinkalot, we should try to play at the lowest tension that we can still tolerate in terms of controllability.

There is one thing to keep in mind, the stronger the tension in the string the higher the theoretical power it can transfer if you can generate the swing speeds to still bend the strings in order to transfer that power.

I make mention of the bow and arrow earlier and will use it as an example. A bow that a child or woman can bend will be more flexible than one a man can and therefore will generate less power. But if you give the bow that a man can bend to a woman then she cannot pull it back far enough to put the bow into enough tension that it has the same power as a bow designed for her. Therefore we do need to match the tension on the strings to the swing speed of the player in order to maximize the transfer of energy.
Very good analogy, now why didn't I think of it!
That's what I've been trying to say all along! The string tension has to be matched to the swing speed for optimal energy transfer. I was trying to show that via an optimal stringbed deformation, and the bow/arrow analogy with differing tensions for child vs. adult is very effective.

This is all my opinion of course and any one is more than welcome to dispute or discuss them.
I appreciate the oppurtunity for discussion. Thanx!

15. No hard and fast rule. Usually I keep a few rackets with different tension. A range from 22lbs to 28lbs tension. The lesser tension helps to generate power ...due to elasticity of the string. The higher tension requires hard hitting to generate the same amount of power. Usually when I get a bit tired I switched my racket to lower tension and this confuse my opponents. Suddenly my pace is different because of the string tension. Ha Ha... its fun anyway not just sticking to one tension. You can really experiment. I also used different rackets...some are heavier for training my wrist. Some are lighter. So I experiment a lot. Enjoy my game...with different opponent. I don't stick to playing with the same gang. I join a few groups in different days of the week. For those opponents who are less powerful, I usually use lower tension to save my energy and make them run around the 4 corners of the court. I can really feel the shuttle bouncing like a tennis ball. Its interesting. With higher tension, I need to use more energy directing the shuttles. I usually use it when I am very fresh and fit. When I feel tired, I use lesser tension rackets.

16. Don't know who put it up originally, but the bow and arrow analogy is the one that I find easiest to visualise.

Let's say you have a 10 year old boy with a bow strung at 10 lbs, and a grown man with an adult bow at 30 lbs.

The boy can pull his bow string back a full 3 feet and fire an arrow, and the man can do the same with the boy's bow.

But when you give the boy the man's 30 lbs bow, he can only pull it back a few inches and so gets no distance at all on the arrow. But the man can pull his 30 lbs bow back the full 3 feet, so gets a LOT more distance on the arrow than he could with the boy's 10 lbs bow.

17. Search for the member "wristworks"... he had some excellent postings and explanations on this topic.

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