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Hard Rubber More Spin?

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Topic: Hard Rubber More Spin?
Posted By: nashron
Subject: Hard Rubber More Spin?
Date Posted: 04/05/2011 at 5:25am
is it true that the more the hardness the rubber than the more lethal spin that it can produce?

what is the disadvantage of using hard rubber compare to soft rubber?

i normally like to use soft rubber... but i think i need to change to hard rubber to produce more spin with my fh. now i use tenergy 05 fx at my fh.


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Now i use DHS Hking 655 but i miss my the moments i use dr neubaeur firewall plus.



Replies:
Posted By: ninglei23
Date Posted: 04/05/2011 at 5:52am
hard rubbers and mid rubbers have more spin and they are consistent than soft rubbers


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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: TheRobot99
Date Posted: 04/05/2011 at 6:05am
Not to mention power production is easier with a harder sponge.

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Ross Leidy Custom, DHS Hurricane III Neos, Nittaku Nodias

Xiom Fuga, Globe 999 National 39, Nittaku Nodias

JOOLA Torre All+, DHS Hurricane II #19 Sponge, Galaxy Moon 38

PTTC VP - 2011-12


Posted By: atv
Date Posted: 04/05/2011 at 6:18am
Hard rubbers are usually difficult to control, it need quite some training to let the ball sink through the sponge to the blade during every contact, especially when looping, and that is the only way to generate the lethal spin.

To change from soft rubber to hard rubber would need more accurate, more practiced and more explosive FH stokes and you need to make some changes to the movement of forearm, contact angle, wrist and brushing/hitting ratio, and more importantly, do more practice to increase dewll time, which is not a big problem when you are using a soft rubber.


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YEO
FH: 729 08 ES
BH: Focus III Snipe
Senkoh-1
FH: H3 Comm
BH: 755


Posted By: ninglei23
Date Posted: 04/05/2011 at 6:32am
then just use mid rubbers it's better



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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: Stavros
Date Posted: 04/05/2011 at 7:07am
Harder rubbers produce more spin. Softer rubbers produce easier spin.

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Blade: Stiga Infinity
FH: Dignics 80
BH: Dignics 05


Posted By: ninglei23
Date Posted: 04/05/2011 at 7:10am
hey stavros is calibra lt easy to use if I already use calibra lt sound max?do I have to adjust?

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: mayuki24
Date Posted: 04/05/2011 at 7:26am
i think soft rubbers would produce much spin than the harder ones because of the simple logic, Hard sponge = power but less spin because the ball would bounce at a shorter time and would not have more dwell time. Soft sponge = less power but much spin and have a greater dwell time because of the softness of the sponge which would grip the ball into the rubber more than the hard ones it just lack power though.

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Nittaku Runlox (C-Pen)
FH:    Andro Rasant Powergrip
BH:   Andro Rasant Grip



Posted By: TTboy07
Date Posted: 04/05/2011 at 7:31am
true with soft rubbers, the ball will sink into the sponge longer thus having longer dwell time creating more spin and having more control. while the hard ones will be faster and more suitable for power play because of the harder sponge.

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Posted By: mayuki24
Date Posted: 04/05/2011 at 8:12am
For the simple logic here it is.

Hard sponge = Fast, less spin and lesser dwell time and a bit harder to control

Soft sponge = a bit slow, much spin and having more dwell time and easier to control with. 

Thumbs Up


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Nittaku Runlox (C-Pen)
FH:    Andro Rasant Powergrip
BH:   Andro Rasant Grip



Posted By: Stavros
Date Posted: 04/05/2011 at 8:43am
Originally posted by ninglei23 ninglei23 wrote:

hey stavros is calibra lt easy to use if I already use calibra lt sound max?do I have to adjust?

I prefer Calibra LT. Harder, faster, spinier lasts longer but it's more difficult to control. 


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Blade: Stiga Infinity
FH: Dignics 80
BH: Dignics 05


Posted By: nashron
Date Posted: 04/05/2011 at 8:49am
I hv observed the specification of harder rubber, their specification is more spin than soft rubber, for example between tenergy 05fx vs tenergy 05, sriver vs sriver fx, soft rubber more speed. Correct me if i am wrong.

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Now i use DHS Hking 655 but i miss my the moments i use dr neubaeur firewall plus.


Posted By: ninglei23
Date Posted: 04/05/2011 at 8:50am
what is the sponge thickness that you perfer for me I am an improving player with good forehand but no that consistent

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: silverhair
Date Posted: 04/05/2011 at 9:00am
ninglei23, you have asked the same question in different threads.  To reiterate, you should be using 1.5mm or 1.8mm.  My suggestion is to use a soft sponge in that thickness.  You may find that it's easier to control and more fun to play.  

If one considers what happens at the ball contact, the ball sinks a bit deeper into soft sponge than hard sponge with the same topsheet and pips geometry.  The force of the stroke creates more of a tension against the ball that is deeper into the sponge than one that is shallower.  That tension is converted into spin.  If the tension is greater because the dwell time of the ball on the racket face is longer, it should generate more spin on the rebound if all the other variables are equal.


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What if there were no hypothetical questions?


Posted By: ninglei23
Date Posted: 04/05/2011 at 9:04am
do I really have to use big slam?Disapprove another rubber that I will have to adjust..........haixt.

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: silverhair
Date Posted: 04/05/2011 at 9:28am
You'll adjust.  No, you don't HAVE to use Big Slam.  There are other rubbers like Mark V that will work well.  Original Sriver 1.5mm is also an option as is Donic Vario 1.5mm.

I recommend Big Slam because many, including me, find it a fun rubber to use.  Great feel, very good control, loud glue-like pop.  

You'll adjust.  It's not like going from Baracuda to OX long pips.  

But do as you will.  The forum is just here to comment and help advise.  Nobody is forcing anybody to to anything.

BTW, what does your coach have to say about your equipment?


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What if there were no hypothetical questions?


Posted By: ninglei23
Date Posted: 04/05/2011 at 9:36am
he say's that it's a good set up and very light.

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: ninglei23
Date Posted: 04/05/2011 at 9:38am
i'll try the donic f3 big slam i triend it already and it's good I just don't like rubber's that are slower than lt sound..sorry silver hair..and thank you. Smile

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: icontek
Date Posted: 04/05/2011 at 9:39am
Originally posted by atv atv wrote:

Hard rubbers are usually difficult to control, it need quite some training to let the ball sink through the sponge to the blade during every contact, especially when looping, and that is the only way to generate the lethal spin.

To change from soft rubber to hard rubber would need more accurate, more practiced and more explosive FH stokes and you need to make some changes to the movement of forearm, contact angle, wrist and brushing/hitting ratio, and more importantly, do more practice to increase dewll time, which is not a big problem when you are using a soft rubber.


+1111111111111111111111

Well said. The reason that many companies produce a "soft sponge" version of favorites (like F3, S3, Calibra Sound, Sriver FX) is so that normal humans with less than pro technique can enjoy some of the benefits of a particular rubber, while not requiring that every single shot have perfect footwork, handspeed, followthrough etc.


sidenote:

if you gave a 14 year old the keys to a ferrari, it's likely that he could drive fast.

...but he would crash a lot.

This is my often used simile for OFF+ rubber and blades.


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http://bit.ly/vLMhuB" rel="nofollow - - RC1042 . OSP Virtuoso AC: PK50 + R42


Posted By: pablogilberto
Date Posted: 04/05/2011 at 9:48am
Ninglei - it's not the equipment - it's  you and your technique.Evil Smile


Posted By: ninglei23
Date Posted: 04/05/2011 at 9:53am
that's it!that's why I don't want to change my rubber.OKAY?

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: stoic
Date Posted: 04/05/2011 at 9:59am

From my experience and logic aside, I think that the hardness of the rubber does not necessarily effect the amount of spin it can produce.

H3 provincial being the hardest rubber I have used, was also one of the spinniest. But Adidas R6 is the softest rubber I have used, and is also one of the spinniest. Perhaps the perceived difference in spin is in fact just a different trajectory. Soft rubbers tend to produce a higher flight curve, which may look like more spin than a lower curve.
 
The way we all perceive the spin on a ball will vary, therefore a better way to measure spin is required to put this debate to the test. Anyone know of a spin measuring method?
 
 


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http://www.static-sounds.com - http://www.static-sounds.com
Check out our tunes!


Posted By: nashron
Date Posted: 04/05/2011 at 10:44am
Soft rubber will rebound faster than hard rubber when contact, will create more speed than spin?

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Now i use DHS Hking 655 but i miss my the moments i use dr neubaeur firewall plus.


Posted By: Cicis
Date Posted: 04/05/2011 at 12:28pm
Soft sponge (usually grippy) = you have to let the ball sink for it to generate spin
Hard sponge (usually tacky) = you have to brush the ball for it to generate spin

is it more proper to say that generating spin on each type of rubbers requires different strokes?


Posted By: stoic
Date Posted: 04/05/2011 at 1:28pm
Originally posted by nashron nashron wrote:

Soft rubber will rebound faster than hard rubber when contact, will create more speed than spin?
 
Soft rubbers allow the ball to sink into the sponge more thereby reducing the rebound speed. The ball rebounds off a hard rubber faster than a soft rubber. Imagine hitting the ball against a wall compared with a cushion. The ball will accelerate faster off of a hard rubber,
 
The rebound speed however does not equate with the speed of the rubber, this is a different type of speed. For example a sheet of Bryce allows the ball to sink into the rubber more than H3, but also has a bigger catapult effect.
 
 
 
 
 


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http://www.static-sounds.com - http://www.static-sounds.com
Check out our tunes!


Posted By: pnachtwey
Date Posted: 04/05/2011 at 2:01pm
Quote
hard rubbers and mid rubbers have more spin and they are consistent than soft rubbers 

So much non sense!!!!  The statement is too general which makes it invalid.  Not all hard rubbers are faster than soft rubbers.  Why do hard rubbers produce more spin?  I am not saying that they can't but there is an underlying reason as to why some rubbers produce more spin than others.  It really isn't a hard or soft issue.   

I can buy a chinese top sheet and put soft or hard rubbers underneath it.  That would eliminate the different in friction.   Now tell me why a soft or hard rubber will generate more spin with the same top sheet?

Leading question.  To you boost or speed glue your chinese rubbers to make them harder?

I think consistency is up to the player preferences and abilities.  

Softer rubber will provide more dwell time.  I agree but why?

Quote
Soft sponge (usually grippy) = you have to let the ball sink for it to generate spin
Hard sponge (usually tacky) = you have to brush the ball for it to generate spin
Yes.

Quote
is it more proper to say that generating spin on each type of rubbers requires different strokes?
Yes, if you are trying to return the ball at the same trajectory.

What really make a rubber fast is not whether it is hard or soft but how fast it will return to its original shape during the impact.  This is a function of its internal friction which affects the coefficient of restitution .
http://wiki.answers.com/Q/What_is_internal_friction%20 - http://wiki.answers.com/Q/What_is_internal_friction
http://wiki.answers.com/Q/What_is_internal_friction%20 - If a hard and soft rubber are hitting the same ball at the same speed the two rubbers will need to absorb the same amount of energy.  What will make one rubber faster than the other is how much energy it returns to the ball.  To return energy to the ball the rubber must spring back fast enough to stay in contact with the ball for as long ( distance wise ) as possible.  As soon as the ball leaves the rubber it the rubber can not return any more energy to the ball.  A harder rubber will not compress as far as a soft rubber when hitting the same ball.  For the two rubbers to return the same amount of energy the ball must be going at the same speed after impact.  The harder rubber must accelerate the ball quicker in a shorter distance than the  software rubber.  It is possible.  I won't make general statements.  A hard super ball is very hard and has a very high coefficient of restitution.  

Now I wonder why hard Chinese rubbers have to be so darn thick?  I think this is why I am an Apollo fan. I can order 1.8mm Apollo.
 
 



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I TT therefore I am


Posted By: Speedplay
Date Posted: 04/05/2011 at 3:43pm
My experience is, hard sponge rubbers (assuming everything else is equal) are capable of generating more spin and speed then soft sponge rubbers, but it is easier to do it with a soft sponge.

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The holy grail


Posted By: Congoman
Date Posted: 04/05/2011 at 4:54pm
Speedplay is right.

How do you generate spin? Two ways, skim the ball and sink the ball in the rubber. There's a video of Waldner doing two types of top spin. Skim, and really hit the ball hard to sink the ball in the rubber.

Hard rubber (Chinese rubber):
Generally a hard sponge, because it has MORE POTENTIAL to create spin, but hard to do so.
Non-scientific example/figure:
Spin range for hard rubber is: 50-250 RPS
You can't flick your wrist to generate spin. Try hardness 40 it feels like a freaking brick.

Soft rubber (Western rubber):
Generally software rubber, more springy. Much easier to generate spin, because it doesn't take much to sink the ball in the rubber, but spin range is lower.
Spin range for soft rubber is: 10-150 RPS

So...Pros and Cons:

Hard rubber:
+ Can generate a lot of spin but gotta hit the ball hard, so that means your forms has to be right (have you seen the chinese nationals play? they all use 40 hardness rubbers)
- Hard rubber is not as good at generating spin for short plays (GENERALLY SPEAKING). Tackiness is there trying to offset that problem.

Soft rubber:
+ can easily generate spin, no "proper" form is required. Flick your wrist and generate spin, period.
- Cannot generate as much spin as hard sponges.

Again, very general comparison, there are many other factors involved too.

Edit: Btw, the reason you generate more spin with hard rubber is it takes much more power to compress the rubber (assuming you compress it so hard so the ball is almost in contact with the blade, it would take more to compress a hard rubber than a soft rubber)


Posted By: silverhair
Date Posted: 04/05/2011 at 5:25pm
Originally posted by Congoman Congoman wrote:

Speedplay is right.

How do you generate spin? Two ways, skim the ball and sink the ball in the rubber. There's a video of Waldner doing two types of top spin. Skim, and really hit the ball hard to sink the ball in the rubber.

Hard rubber (Chinese rubber):
Generally a hard sponge, because it has MORE POTENTIAL to create spin, but hard to do so.
Non-scientific example/figure:
Spin range for hard rubber is: 50-250 RPM
You can't flick your wrist to generate spin. Try hardness 40 it feels like a freaking brick.

Soft rubber (Western rubber):
Generally software rubber, more springy. Much easier to generate spin, because it doesn't take much to sink the ball in the rubber, but spin range is lower.
Spin range for soft rubber is: 10-150 RPM

So...Pros and Cons:

Hard rubber:
+ Can generate a lot of spin but gotta hit the ball hard, so that means your forms has to be right (have you seen the chinese nationals play? they all use 40 hardness rubbers)
- Hard rubber is not as good at generating spin for short plays (GENERALLY SPEAKING). Tackiness is there trying to offset that problem.

Soft rubber:
+ can easily generate spin, no "proper" form is required. Flick your wrist and generate spin, period.
- Cannot generate as much spin as hard sponges.

Again, very general comparison, there are many other factors involved too.

Edit: Btw, the reason you generate more spin with hard rubber is it takes much more power to compress the rubber (assuming you compress it so hard so the ball is almost in contact with the blade, it would take more to compress a hard rubber than a soft rubber)

Could you provide some references?  Especially references to the rate of spin and info to illustrate what you've said?  


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What if there were no hypothetical questions?


Posted By: pnachtwey
Date Posted: 04/05/2011 at 5:53pm
More non sense!
If there is no spring or stretch across the surface of the rubber the spin is limited by the tangential speed of the paddle.   The question then is which rubber provides more surface stretch or spring, hard or soft?

Potential doesn't spin balls.   I can brush loop with soft rubbers too.  I can brush loop with T05 or Mark V.
When evaluating rubbers you need to remove the influence of technique and the human element.
The question should be what rubber will generate the most spin with the same stroke.

Apparently I can spin a ball with the flick of my wrist with soft rubber but can't with hard rubber.  Yet the hard rubber generates more spin.  ??????

Congoman, you must think EU-JP players are very lame to only achieve 150 rpm.   6000 RPM ( 100 RPS ) is closer to the real number.  On Greg Letts site he says 150 RPS ( 9000 RPM ) but I doubt everyone can spin the ball that fast.  BTW, 250 RPM is very slow.

I have a video some where that shows a looper and chopper playing in front of high speed cameras.  The video indicates the choppers ball is rotating at 137 RPS.   The looper must at least match that speed or the ball will go into the net.




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I TT therefore I am


Posted By: chu_bun
Date Posted: 04/05/2011 at 6:15pm
For serving, I find it's easier to put spin on the ball using hard rubber.  Softer rubbers tend to be bouncier and the ball *seems* to jump off and carries less spin.

However, it could be comparing apple and orange here.  My hard rubbers are Chinese sticky, while my soft ones are Euro and tensor.


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Clipper Wood, Sanwei Gears FH, Sanwei T88-I BH.


Posted By: Speedplay
Date Posted: 04/05/2011 at 6:58pm
Originally posted by pnachtwey pnachtwey wrote:

More non sense!

I have a video some where that shows a looper and chopper playing in front of high speed cameras.  The video indicates the choppers ball is rotating at 137 RPS.   The looper must at least match that speed or the ball will go into the net


Yes, you are right, it is more non sense, thanks for admitting it, cause in this example, you seem to forget everything about blade angle. You don't need to match the speed of the incoming ball, simply adjust your blade angle.

The fact that a soft rubber is easier to generate spin with don't equal to it being able to produce more spin.

I did consider giving it a go to explain it to you, but, wise from previous attempts, I say, stick to your theories, the rest of us rely on the results we get in real life.

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The holy grail


Posted By: debraj
Date Posted: 04/05/2011 at 6:59pm
hard rubbers produce more brush spin in serves and more sponge spin in power loops.

soft rubbers produce decent spin in slow loops. 


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729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
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Posted By: pnachtwey
Date Posted: 04/05/2011 at 7:23pm
Originally posted by Speedplay Speedplay wrote:


Yes, you are right, it is more non sense, thanks for admitting it, cause in this example, you seem to forget everything about blade angle. You don't need to match the speed of the incoming ball, simply adjust your blade angle.
Do you open your blade when returning back spin with topspin and actually hit the ball up?  If the paddle is neurtral you need to match the rotational speed of the ball.  If you close your paddle your better brush the ball with a higher tangential speed to keep the ball from going into the net.

Quote
The fact that a soft rubber is easier to generate spin with don't equal to it being able to produce more spin.
What makes it easier to generate spin with soft rubbers?
What makes a rubber able to generate more spin?
I have told you what makes a spiny rubber spiny but you refuse listen as if the Pope said it is't possible.
Everyone is talking in generalities and these are false because there are exceptions.  It is much easier for me to generate spin with my T05 than with Reflectoid.  T05 is harder so that blow your theory.

Quote
I did consider giving it a go to explain it to you, but, wise from previous attempts, I say, stick to your theories, the rest of us rely on the results we get in real life.
Your argument doesn't hold true in all cases and is therefore false.  It is the same as those that make the argument that heavy paddles have more power or hit the ball faster when we all know there are bigger heavier defensive paddle that don't.

This is kind of like talking to people that think the universe rotates around the earth instead of taking a step back and looking at what is really going on.





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I TT therefore I am


Posted By: nashron
Date Posted: 04/06/2011 at 12:43am
Why most of top china players men use chinese rubber on their fh? Any reasons relate to hardness n spin?

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Now i use DHS Hking 655 but i miss my the moments i use dr neubaeur firewall plus.


Posted By: ninglei23
Date Posted: 04/06/2011 at 1:04am
because it is hard to use chinese rubber on your BH

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Yinhe V-14
FH:Xiom Vega Pro
BH:Donic Baracuda


Posted By: mayuki24
Date Posted: 04/06/2011 at 1:35am
Originally posted by pablogilberto pablogilberto wrote:

Ninglei - it's not the equipment - it's  you and your technique.Evil Smile




+111111111111111111111111111111111111  Clap


Originally posted by nashron nashron wrote:

Why most of top china players men use chinese rubber on their fh? Any reasons relate to hardness n spin?

as i have read here in the forums, Chinese players said that they need more speed than spin nowadays since the sped glue ban era is done now, they just need to have super speed in rallies/ every shot that they will make, i think they also dont care about the spin but the speed that they would produce in every shot. Watching pro players play they lose because of the placing of the ball and the speed that their opponent have delivered, you cant even think that they are losing against super spin shots because they know how to return it and they are just brushing the ball thats why hard sponge is most preferable for them. 

Also they cant use chinese rubber on backhand because their set - up would be heavy and only a few of them have a good backhand and know how to brush the ball in the backhand easily thats why they are using tenergy series. Tenergy rubbers have high throw and you can produce spin easily and doesnt require to much wrist action or movement because of the spring sponge technology. Big smile


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Nittaku Runlox (C-Pen)
FH:    Andro Rasant Powergrip
BH:   Andro Rasant Grip



Posted By: roundrobin
Date Posted: 04/06/2011 at 1:53am
Originally posted by nashron nashron wrote:

is it true that the more the hardness the rubber than the more lethal spin that it can produce?

what is the disadvantage of using hard rubber compare to soft rubber?

i normally like to use soft rubber... but i think i need to change to hard rubber to produce more spin with my fh. now i use tenergy 05 fx at my fh.


From my experience, I could definitely chop away from the table with a lot more spin with hard sticky Chinese rubbers than with soft Japanese or German rubbers.  The difference is quite noticeable.


Posted By: Speedplay
Date Posted: 04/06/2011 at 2:24am
Pnachtwey;

First statement is still wrong, you still forget to mention at what height you hit the ball. If it's high enough, you can open your balde and hit forward only, with out adding any top spin at all and still clear the net and land the ball on the table.

Second statement, it's not all about hard or soft, I thought I covered this by saying if all other things are equal? What part didn't you get about that? You are comparing apples to oranges. I haven't used Reflectoid, so I don't know what it's like, but Tenergy have very high grip on the surface, which makes it easy to use even for brush looping.

Third statement, again,comparing apples to oranges. When the weight is discussed, you can not bring in other blades to the argument, as it is irrelevant.

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The holy grail


Posted By: pnachtwey
Date Posted: 04/06/2011 at 4:04am
Quote
First statement is still wrong, you still forget to mention at what height you hit the ball. If it's high enough, you can open your balde and hit forward only, with out adding any top spin at all and still clear the net and land the ball on the table. 
It isn't wrong.  I was just assuming I am playing against a good chopper than hits the ball fast, deep, and low.  I wasn't assuming I was hitting high balls from a newbie.

Quote
Second statement, it's not all about hard or soft, I thought I covered this by saying if all other things are equal?
So what makes the ball spin faster when hit by a hard rubber than a ball hit by a soft rubber?  Just saying so doesn't make it so.  Lets hear a rational explanation that can pass my absurdity test.   If the rubber is made twice as hard will it generate twice as much spin?  If a rubber is 10% harder than another will it generate 10% more spin with the same stroke?  If not then harder isn't always spinier and there must be something else that really causes the extra spin.

What about the hard dried out rubber on my 40 year old paddle?  It is slicker than my Best Anti!  So much for harder always being spinier.

Quote
Third statement, again,comparing apples to oranges. When the weight is discussed, you can not bring in other blades to the argument, as it is irrelevant.
Why not? We were not talking about apples and oranges we were talking about paddles.  Many have made the general statement that heavier paddles are 'faster'.  There haven't been any qualifications made on the type of paddle. I have admitted that the speed does increase by a small percentage but not proportional to the weight of the paddle but you have now admitted that 'other' blades may make your claims invalid.

No one ever answered my previous absurdity test for the mass of paddles.  If I have a paddle twice as heavy will the speed after impact be twice as fast?  If the paddle is 10% heavier than another will the speed after impact be 10% greater than the other?  If not there there is something else that really affects the speed after impact much more than the mass of the paddle.

Give it up. The physics aren't on your side.



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I TT therefore I am


Posted By: nashron
Date Posted: 04/06/2011 at 4:28am
between new soft rubber vs old hard rubber is the top layer of the rubber is different :) i wonder what is the different between chinese rubber.. the top layer and sponge compare to western/japanese rubber... both new :)

Originally posted by pnachtwey pnachtwey wrote:

Quote
First statement is still wrong, you still forget to mention at what height you hit the ball. If it's high enough, you can open your balde and hit forward only, with out adding any top spin at all and still clear the net and land the ball on the table. 
It isn't wrong.  I was just assuming I am playing against a good chopper than hits the ball fast, deep, and low.  I wasn't assuming I was hitting high balls from a newbie.

Quote
Second statement, it's not all about hard or soft, I thought I covered this by saying if all other things are equal?
So what makes the ball spin faster when hit by a hard rubber than a ball hit by a soft rubber?  Just saying so doesn't make it so.  Lets hear a rational explanation that can pass my absurdity test.   If the rubber is made twice as hard will it generate twice as much spin?  If a rubber is 10% harder than another will it generate 10% more spin with the same stroke?  If not then harder isn't always spinier and there must be something else that really causes the extra spin.

What about the hard dried out rubber on my 40 year old paddle?  It is slicker than my Best Anti!  So much for harder always being spinier.

Quote
Third statement, again,comparing apples to oranges. When the weight is discussed, you can not bring in other blades to the argument, as it is irrelevant.
Why not? We were not talking about apples and oranges we were talking about paddles.  Many have made the general statement that heavier paddles are 'faster'.  There haven't been any qualifications made on the type of paddle. I have admitted that the speed does increase by a small percentage but not proportional to the weight of the paddle but you have now admitted that 'other' blades may make your claims invalid.

No one ever answered my previous absurdity test for the mass of paddles.  If I have a paddle twice as heavy will the speed after impact be twice as fast?  If the paddle is 10% heavier than another will the speed after impact be 10% greater than the other?  If not there there is something else that really affects the speed after impact much more than the mass of the paddle.

Give it up. The physics aren't on your side.



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Now i use DHS Hking 655 but i miss my the moments i use dr neubaeur firewall plus.


Posted By: pnachtwey
Date Posted: 04/06/2011 at 5:01am


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I TT therefore I am


Posted By: pnachtwey
Date Posted: 04/06/2011 at 5:18am
Early on I suggest that a two identical top sheets could be bought and one placed on a hard sponge and the other on a soft sponge.  I asked for a justification for why the hard hard sponge will provide more spin than the soft sponge.  No one has explained why a hard sponge will provide more spin than an soft sponge.

Also, the assertion was that hard rubbers are spinier than soft rubbers.  There were no other qualifiers so my 40 year old dried out hard rubber is still an example of how the general statement that hard rubbers are spinier than soft rubbers is false.

For some reason I can't type from my iPad or edit that blank comment from another computer.  The empty comment can be deleted.





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I TT therefore I am


Posted By: APW46
Date Posted: 04/06/2011 at 5:34am
Originally posted by pnachtwey pnachtwey wrote:

More non sense!
 

I have a video some where that shows a looper and chopper playing in front of high speed cameras.  The video indicates the choppers ball is rotating at 137 RPS.   The looper must at least match that speed or the ball will go into the net.


 in your own words 'non sense'

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The Older I get, The better I was.


Posted By: silverhair
Date Posted: 04/06/2011 at 8:05am
Still no web references to why hard sponge generates more spin than soft sponge?  

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What if there were no hypothetical questions?


Posted By: Peter C
Date Posted: 04/06/2011 at 8:47am
pnatchwey

When I read your posts, your Modus Operandi reminds me of the legendary Sid of Millennium.

Like Sid; you have strong views, which you don't like being questioned and your riposte is to ask questions such as, "Lets hear a rational explanation that can pass my absurdity test."

Why should Speedplay or any other intelligent forum member, for that matter; take you or such a question seriously and waste their time answering such a hypothetical question?

And the truth is they don't need to, as it's the flaws in your thinking that deserve to be questioned; not the other way around.

Speedplay has a good reputation on this forum, because he is knowledgeable about Table Tennis and gives good advice.

Rather than insult him, you'd be wise to recognise that he is pointing out the flaws in your thinking, not his.







Posted By: stoic
Date Posted: 04/06/2011 at 10:40am
I think we have to eliminate all the variables to create a fair test. A list of all the variables would be useful in this case, so here's some which come to mind:
 
  • Spring of the rubber
  • Speed of the paddle
  • Angle of the paddle
  • Initial spin of the ball
  • Air temperature (Cold air is more dense, thus producing more friction)
  • Humidity (water is denser than air so produces more friction)
  • Surface friction of the rubber
 
You get the picture, so all of the above would have to be identical for each test of a rubber. I think pnachtwey's posts are the closest to finding an answer so far:  
 
Originally posted by pnachtwey pnachtwey wrote:

More non sense!
If there is no spring or stretch across the surface of the rubber the spin is limited by the tangential speed of the paddle.   The question then is which rubber provides more surface stretch or spring, hard or soft?
 
- The spin is also limited by air temperature, humidity and surface friction of the rubber. I think there are many factors we are not considering in this debate. When each person evaluates a rubber, there many factors which have not been controlled thus not creating a fair test. 

Potential doesn't spin balls.   I can brush loop with soft rubbers too.  I can brush loop with T05 or Mark V.
When evaluating rubbers you need to remove the influence of technique and the human element.
The question should be what rubber will generate the most spin with the same stroke.
 
+1

Apparently I can spin a ball with the flick of my wrist with soft rubber but can't with hard rubber.  Yet the hard rubber generates more spin.  ??????
 
- The hardness or softness of the rubber is not the only factor when considering spin.

Congoman, you must think EU-JP players are very lame to only achieve 150 rpm.   6000 RPM ( 100 RPS ) is closer to the real number.  On Greg Letts site he says 150 RPS ( 9000 RPM ) but I doubt everyone can spin the ball that fast.  BTW, 250 RPM is very slow.
 
- Obviously a misunderstanding with measurements

I have a video some where that shows a looper and chopper playing in front of high speed cameras.  The video indicates the choppers ball is rotating at 137 RPS.   The looper must at least match that speed or the ball will go into the net.

- In certain situations, yes the looper must match the RPS.
 


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Posted By: pnachtwey
Date Posted: 04/06/2011 at 12:40pm
Originally posted by APW46 APW46 wrote:

Originally posted by pnachtwey pnachtwey wrote:

More non sense!

I have a video some where that shows a looper and chopper playing in front of high speed cameras.  The video indicates the choppers ball is rotating at 137 RPS.   The looper must at least match that speed or the ball will go into the net.

 in your own words 'non sense'
Which part? 137 RPS or the matching surface and tangential speeds?
Are you saying that the looper doesn't have to match or exceed the surface speed of the ball with the tangential speed of the paddle.  This will only work if you the ball is high and will still make it over then net even if it is hit downwards or you open up your paddle to hit the ball up.  Opening the paddle will get the ball back but with a lower spin than when the ball came over net.
I am eager to hear how you loop chopped balls.   How fast must the paddle go to loop a ball with a 100 RPS back spin?  Inquiring minds want to know.  Assume the ball is traveling horizontally at the top of the bounce but the ball must be hit back horizontally to make it over the net.


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I TT therefore I am


Posted By: pnachtwey
Date Posted: 04/06/2011 at 1:13pm
Originally posted by stoic stoic wrote:

I think we have to eliminate all the variables to create a fair test. A list of all the variables would be useful in this case, so here's some which come to mind:
 
  • Spring of the rubber
  • Speed of the paddle
  • Angle of the paddle
  • Initial spin of the ball
  • Air temperature (Cold air is more dense, thus producing more friction)
  • Humidity (water is denser than air so produces more friction)
  • Surface friction of the rubber
 
You get the picture, so all of the above would have to be identical for each test of a rubber. I think pnachtwey's posts are the closest to finding an answer so far:
OK, but assuming all those things are equal and the same top sheets are on a hard and soft sponge, what would cause one to spin more than the other.   I just bought a second Samsonov Alpha with a Rakza 7 1.8mm and a Rakza 7 soft max.  It will be interesting to compare the two.  The top sheets are the same but the rubbers are different.   Does anyone want to make a bet as to which will generate the most spin?
 
Originally posted by pnachtwey pnachtwey wrote:

- The spin is also limited by air temperature, humidity and surface friction of the rubber. I think there are many factors we are not considering in this debate. When each person evaluates a rubber, there many factors which have not been controlled thus not creating a fair test. 
In the same enviroment the test will be fair.  They will be tested in an air conditioned enviroment.  The top sheets are the same.  If I decide to test with the two Samsonov Alphas the paddles will be the same. I have a robot and a crude laser alignment system and a vice to hold the paddle.  Is that good enough?   This wil just eat into my  practice time.

Quote
- The hardness or softness of the rubber is not the only factor when considering spin.
We agree and it is one of those other factors that really determine if the rubber is spiny or not.
I am sure my hard dried out 40 year old paddle will not be as spinny as Rakza 7 soft. 

Actually,  I think it is the spring in the rubber that make the difference.   Any decent rubber will not let the ball slide after the first few micro seconds of contact.  Once the ball pushes in to the rubber there will be enough friction where the ball will not slip relative to the rubber.  If there is no stretching across the surface of the rubber the ball can not be spun any faster than the tangential speed of the paddle since the paddle and the ball are traveling at the same speed.   If this were the case then all spin would be limited by the tangential paddle speed and all rubbers with decent friction would spin the same.

There is a spring action that is across the surface of the paddle that causes the extra spin.  Take a ball and push it against the paddle and then try to move across the paddle without the ball slipping on the surface.  You can see that the ball will stretch the rubber a millimeter or two.  The rubber that snaps back to the undistored position faster provides the most spin.


   




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I TT therefore I am


Posted By: bluebucket
Date Posted: 04/06/2011 at 1:16pm
Mate the back spinning ball will stop dead as soon as you hit it anyway, not that it has much left on it after the bounce. The energy in a chopped balls spin is nothing compared to being hit, be lucky to change the angle on the shot more than a couple of degrees. It's of no consequence these days


Posted By: silverhair
Date Posted: 04/06/2011 at 1:36pm
Originally posted by Peter C Peter C wrote:

pnatchwey

When I read your posts, your Modus Operandi reminds me of the legendary Sid of Millennium.

Like Sid; you have strong views, which you don't like being questioned and your riposte is to ask questions such as, "Lets hear a rational explanation that can pass my absurdity test."

Why should Speedplay or any other intelligent forum member, for that matter; take you or such a question seriously and waste their time answering such a hypothetical question?

And the truth is they don't need to, as it's the flaws in your thinking that deserve to be questioned; not the other way around.

Speedplay has a good reputation on this forum, because he is knowledgeable about Table Tennis and gives good advice.

Rather than insult him, you'd be wise to recognise that he is pointing out the flaws in your thinking, not his.



Why the personal attack?  Why not stay on topic?  

Speedplay has produced no references to back up any of his claims.  pnatchwey is using logic to question the apparently unproven claims by Speedplay.

And I don't have any confidence in the reputation of someone who cannot back their claims.  




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What if there were no hypothetical questions?


Posted By: roundrobin
Date Posted: 04/06/2011 at 2:09pm
Originally posted by pnachtwey pnachtwey wrote:

Early on I suggest that a two identical top sheets could be bought and one placed on a hard sponge and the other on a soft sponge.  I asked for a justification for why the hard hard sponge will provide more spin than the soft sponge.  No one has explained why a hard sponge will provide more spin than an soft sponge.

Also, the assertion was that hard rubbers are spinier than soft rubbers.  There were no other qualifiers so my 40 year old dried out hard rubber is still an example of how the general statement that hard rubbers are spinier than soft rubbers is false.

For some reason I can't type from my iPad or edit that blank comment from another computer.  The empty comment can be deleted.





Because of my duty at our association, I had the chance to play with many top players and try out many of their equipments.  Time and time again the spinniest loops and serves came from Chinese players with Chinese sticky topsheet and med-hard sponge over the likes of T05, Donic, Yasaka and Stiga users.  I have also tried the same Chinese topsheet with softer sponge variants and the absolute amount of spin that they can produce is significantly less than harder sponge ones that such top players prefer.  This is strictly based on my own experience.  My observation is when executing hardest loops, the hard sponge used by Chinese players does not bottom out as easily as softer ones, so they have an extra gear at the top to add even more pressure/friction to the ball.


Posted By: bluebucket
Date Posted: 04/06/2011 at 2:18pm
Knowing some physics isn't going to help you play table tennis if you don't understand how the game works and how the ball reacts to a rubber and blade because then you also have no clue about what physics you are talking about. That's the problem. 

There is nothing to argue about re soft sponge vs hard sponge. A stiffer rubber will always have more power than a soft one if stretched the same amount, it only depends on how strong or weak the player is as to what is his ideal sponge hardness. There's always a point where you start to go backwards again due to lack of speed/strength. Rubber makers don't make all those different hardness's just for the fun of it, they make them to suit the power of as many players as possible


Posted By: roundrobin
Date Posted: 04/06/2011 at 2:54pm
Originally posted by bluebucket bluebucket wrote:



There is nothing to argue about re soft sponge vs hard sponge. A stiffer rubber will always have more power than a soft one if stretched the same amount, it only depends on how strong or weak the player is as to what is his ideal sponge hardness. There's always a point where you start to go backwards again due to lack of speed/strength. Rubber makers don't make all those different hardness's just for the fun of it, they make them to suit the power of as many players as possible


+1.  Well said.


Posted By: Speedplay
Date Posted: 04/06/2011 at 3:47pm
Originally posted by silverhair silverhair wrote:


Originally posted by Peter C Peter C wrote:

pnatchweyWhen I read your posts, your Modus Operandi reminds me of the legendary Sid of Millennium. Like Sid; you have strong views, which you don't like being questioned and your riposte is to ask questions such as, "L<span style="">ets hear a rational explanation that can pass my absurdity test.</span>"Why should Speedplay or any other intelligent forum member, for that matter; take you or such a question seriously and waste their time answering such a hypothetical question?And the truth is they don't need to, as it's the flaws in your thinking that deserve to be questioned; not the other way around. Speedplay has a good reputation on this forum, because he is knowledgeable about Table Tennis and gives good advice.Rather than insult him, you'd be wise to recognise that he is pointing out the flaws in your thinking, not his.


Why the personal attack?  Why not stay on topic?  
Speedplay has produced no references to back up any of his claims.  pnatchwey is using logic to question the apparently unproven claims by Speedplay.
And I don't have any confidence in the reputation of someone who cannot back their claims.  


Peter C, thanks for the vote of confidence.

Silverhair, I honestly don't feel I need to spend time to back up my claims against some one who refuses to stay on topic. If he was truly interested to learn (instead of trying to teach, which he clearly isn't knowledgeble enough to do) I might consider going in to the technical aspects of this, but when he brings up his "dead" rubber as an example, it shows to me that he don't want to learn anything.

It was the same story with the paddles, as soon as he was left with out answers, he begun to bring up the fact that a heavy def blade was slower then a heavy off blade. No one was arguing about that, the discussion was always about 2 blades with virtually the same construction, and the heavier of these was always the faster one. Do I know how to explain all the science behind this? No, I don't, but I've experienced it in real life, which is enough proof for me. If Pnachtwey is as brilliant as he likes to suggest, he should rather look at his formulas and try to make them work with reality then trying to change the reality to suit his formulas.

For the record, I said that hard sponge provides a greater potential to create spin, not that it always will create more spin, cause it reqires more effort. A small hint though,why do a rubber bottom out, what happens when a rubber bottoms out and which rubber, hard or soft, is most likely to bottom out?

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The holy grail


Posted By: pnachtwey
Date Posted: 04/06/2011 at 4:00pm
Originally posted by bluebucket bluebucket wrote:

Knowing some physics isn't going to help you play table tennis if you don't understand how the game works and how the ball reacts to a rubber and blade because then you also have no clue about what physics you are talking about. That's the problem.
I understand how the game works.  There is nothing in table tennis that violates the laws of physics.  

Quote  
There is nothing to argue about re soft sponge vs hard sponge. A stiffer rubber will always have more power
than a soft one if stretched the same amount, it only depends on how strong or weak the player is as to what is his ideal sponge hardness. 
Rubbers don't have power or generate power unless you burn them to create heat.  Then you could power a steam engine or Stirling engine.  A rubber can not pedal your bike or turn a crank to light a light bulb but you can.  You generate the power, not the rubber.  You can move by yourself.  The rubber can not.

A harder sponge will require a faster impact speed ( a higher energy ball ) to compress or stretch the rubber the same amount as a slower ball impacting a softer sponge.   If the energy ( speed ) of two balls impacting the soft and hard rubbers are the same the ball hitting the hard rubber will not compress or stretch the harder sponge as far as the other ball that hits the soft rubber.   So now the sponges are compressed.  The real question is how much of that energy is returned to the ball and why.

Many are repeating hard rubbers are ALWAYS faster/spinier and can't back up their arguments.  Again there is the absurdity test.  If the rubber is twice as hard will it be twice as fast or twice as spiny?  So far this question has be dodged.


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I TT therefore I am


Posted By: debraj
Date Posted: 04/06/2011 at 4:19pm
Originally posted by pnachtwey pnachtwey wrote:

 

Many are repeating hard rubbers are ALWAYS faster/spinier and can't back up their arguments.  Again there is the absurdity test.  If the rubber is twice as hard will it be twice as fast or twice as spiny?  So far this question has be dodged.


Yes, it will be!!... subject to other variables remaining same, like:
- grippiness/tackiness of topsheet
- topsheet thickness
- pip structure size and distribution
- hand-speed in linear range ( if it bottoms out it's no more in linear range)
- angle of impact




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729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
http://youtu.be/y9y9nE9g778" rel="nofollow - vid1
http://youtu.be/xqNy786yGOs" rel="nofollow - Vid 2


Posted By: cougar3219
Date Posted: 04/06/2011 at 4:47pm
LOL. I have the perfect setup for this topic. On my foerhand I have Nimbus medium an my Backhand I have NImbus soft. Now which rubber do you suppose give me the greatest potenial for spin. BTW, the blade I use is the Samsonov Alpha blade.

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Blade: Timo Boll Spirit (st)

FH Rubber: Donic Baracuda

BH Rubber: Donic Baracuda Big Slam





Blade: Stratus Power Wood (an)

FH Rubber: Donic Baracuda

BH Rubber: Donic Baracuda


Posted By: mercuur
Date Posted: 04/06/2011 at 4:48pm
  I have played ritc 729 topsheet with several sponges and also hurricane II with softer and hard sponge. My reason to prefer the harder sponges is mainly my low speed / high spin brushloops on incoming backspin. With soft sponge there is a lack "phenom".

But soft / hard is relative. I could also put ever harder sponge upto concrete-hard underneath that ritc topsheet (for testing) and somewhere the spin will decrease. I suppose there is a certain optimum for a certain topsheet on a certain blade and for a certain player and even for one player for different strokes (to make it even more complex..). Harder then that spin decreases softr it increases. What,s beter now hard or soft ? Imposible to say it like that because of such relativety.

Second thing to not forget is that a soft sponge hardens out on the blade quicker. Bottoming out for instance things really get hard not soft and this allready can happen to a lesser extend on lower impact ; in millimeter or micrometer a soft sponge compresses more with same impact. The more compressed soft sponge can be as hard as the less compressed hard sponge but the forces are less spread over the woodsurface for the soft sponge. The hardness of the wood comes through more then. On a soft blade a softer sponge can still be softer for the setup while on a hard wood the hard sponge shields the wood it can be reversed.

A thing that has not been mentioned is the possible tangentiallity for brushing.

With a harder rubber brushed thin perpendicular to the incoming speed the ball doesn,t dig a hole in the rubber. The effective momentum put on the ball is bigger then because the effective distance between where the bal is touched with the rubber and it,s center is half the diameter. If the topsheet is also tacky it is possible to brush extremely thin creating the highest possible momentum with the lowest speed.

If the sponge is soft to get enough contact force between topsheet and ball this will make the ball penetrate the rubber more and the effective distance for spinmomentum decreases when trying to "spin the ball up" you start to hit from underneath the ball, partly lifting it instead of putting more pure spin on. That means more need to be cautious for a slow loop.
The abbillity to create extreme and variable spin/speed ratio,s decreases with that.



Posted By: silverhair
Date Posted: 04/06/2011 at 4:48pm
Originally posted by Speedplay Speedplay wrote:

 

Silverhair, I honestly don't feel I need to spend time to back up my claims against some one who refuses to stay on topic. If he was truly interested to learn (instead of trying to teach, which he clearly isn't knowledgeble enough to do) I might consider going in to the technical aspects of this, but when he brings up his "dead" rubber as an example, it shows to me that he don't want to learn anything.



When you make claims such as you have, it is necessary to back up those claims with references.  Failing to provide those references, especially when they have been questioned (as they definitely HAVE been questioned) results in a loss of credibility and the claims being dismissed as unsupported opinion.

So, once again, please provide references to back you claims.  I have stayed on topic, this is my third request.  





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What if there were no hypothetical questions?


Posted By: Congoman
Date Posted: 04/06/2011 at 5:07pm
Originally posted by silverhair silverhair wrote:

Still no web references to why hard sponge generates more spin than soft sponge?  


If you are really into it, knock yourself out...

http://adsabs.harvard.edu/abs/1953Natur.172..169L


Posted By: APW46
Date Posted: 04/06/2011 at 5:20pm
Originally posted by pnachtwey pnachtwey wrote:

Originally posted by APW46 APW46 wrote:

Originally posted by pnachtwey pnachtwey wrote:

More non sense!

I have a video some where that shows a looper and chopper playing in front of high speed cameras.  The video indicates the choppers ball is rotating at 137 RPS.   The looper must at least match that speed or the ball will go into the net.

 in your own words 'non sense'
Are you saying that the looper doesn't have to match or exceed the surface speed of the ball with the tangential speed of the paddle.  
 YES, Prove me wrong. You can't because I know that it is actually impossible for the arm to make the speed required, what actually happens is that the bat angle compensates and lifts the ball.
You cannot in physics produce me any evidence that the physical arm of a player can reach the arm speed that you say is dependant on the said stroke. What actually happens is that the bat angle compensates for the backspin to lift the ball, the 'brush' is irrelevant on heavy backspin, it will allways end up in a net ball, without the bat angle compensation.


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The Older I get, The better I was.


Posted By: bluebucket
Date Posted: 04/06/2011 at 5:56pm
We can certainly work out the arm speed of a looper easy enough a quick look at a video of a decent club player and some sums makes it about 13 meters per second at impact. Not so easy for me to work out how fast the ball is spinning


Posted By: debraj
Date Posted: 04/06/2011 at 6:04pm
)
Originally posted by APW46 APW46 wrote:

.... I know that it is actually impossible for the arm to make the speed required, what actually happens is that the bat angle compensates and lifts the ball.


sorry which arm speed are we talking about? 137 RPS is the rotational speed on the ball. 

which means for a 40mm ball its 137 * 40 * (pi=3.14)= 17207mm/sec linear speed =17 meters per sec

definitely most of us loopers match it.... and that's why we can actually loop against a backspin with the racket completely over the ball or at least the racket facing little downwards 

.. and the ball hanging below. Which means the angle of the bat doesn't provide any  vertical lift vector (cos theta LOL)  to the ball to lift it or keep it lifted. 

... yeeeeeehhhhhhhh !!! Hug  



now where's my prize for brushing up school maths?  Confused


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729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
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http://youtu.be/xqNy786yGOs" rel="nofollow - Vid 2


Posted By: bluebucket
Date Posted: 04/06/2011 at 6:09pm
I wouldn't think anyone can make 17 meters a second :S, I'd say the very best pros with straight arms would be around 14 or 15?


Posted By: debraj
Date Posted: 04/06/2011 at 6:12pm
then that's an exceptional chopper... and i will push that ball. Angry


but truely... you need that peak hand speed only for a 50th of a second or so. and in general, (taking away that 137 rps)... i proves in general you don't essentially need help from blade angle to lift an underspin!! 


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729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
http://youtu.be/y9y9nE9g778" rel="nofollow - vid1
http://youtu.be/xqNy786yGOs" rel="nofollow - Vid 2


Posted By: smackman
Date Posted: 04/06/2011 at 6:14pm
Originally posted by roundrobin roundrobin wrote:

Originally posted by pnachtwey pnachtwey wrote:

Early on I suggest that a two identical top sheets could be bought and one placed on a hard sponge and the other on a soft sponge.  I asked for a justification for why the hard hard sponge will provide more spin than the soft sponge.  No one has explained why a hard sponge will provide more spin than an soft sponge.

Also, the assertion was that hard rubbers are spinier than soft rubbers.  There were no other qualifiers so my 40 year old dried out hard rubber is still an example of how the general statement that hard rubbers are spinier than soft rubbers is false.

For some reason I can't type from my iPad or edit that blank comment from another computer.  The empty comment can be deleted.





Because of my duty at our association, I had the chance to play with many top players and try out many of their equipments.  Time and time again the spinniest loops and serves came from Chinese players with Chinese sticky topsheet and med-hard sponge over the likes of T05, Donic, Yasaka and Stiga users.  I have also tried the same Chinese topsheet with softer sponge variants and the absolute amount of spin that they can produce is significantly less than harder sponge ones that such top players prefer.  This is strictly based on my own experience.  My observation is when executing hardest loops, the hard sponge used by Chinese players does not bottom out as easily as softer ones, so they have an extra gear at the top to add even more pressure/friction to the ball.
What would happen if you gave one of those chinese players used a say LT sound and they did the same stroke? To me a fast shot is not always the spinniest and the timing of a loop type drive at almost before the top of the bounce will go like a rocket becuase of two things 
1. the timming of the shot (as in hitting the ball early so it is already back to the other side before another ball that has been hit latter (so in some case if you hit the ball 3 inches back +the ball has to go 3inche forward to get back to the place where the other person hit it = therfore 6 inches faster per time factor
2. impact from the bat and speed at the right moment


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Ulmo Duality,Donic BlueGrip C2 red max ,Yinhe Super Kim Ox Black
NZ table tennis selector, third in the World (plate Doubles)I'm Listed on the ITTF website


Posted By: roundrobin
Date Posted: 04/06/2011 at 6:28pm
Originally posted by smackman smackman wrote:

Originally posted by roundrobin roundrobin wrote:

Originally posted by pnachtwey pnachtwey wrote:

Early on I suggest that a two identical top sheets could be bought and one placed on a hard sponge and the other on a soft sponge.  I asked for a justification for why the hard hard sponge will provide more spin than the soft sponge.  No one has explained why a hard sponge will provide more spin than an soft sponge.

Also, the assertion was that hard rubbers are spinier than soft rubbers.  There were no other qualifiers so my 40 year old dried out hard rubber is still an example of how the general statement that hard rubbers are spinier than soft rubbers is false.

For some reason I can't type from my iPad or edit that blank comment from another computer.  The empty comment can be deleted.





Because of my duty at our association, I had the chance to play with many top players and try out many of their equipments.  Time and time again the spinniest loops and serves came from Chinese players with Chinese sticky topsheet and med-hard sponge over the likes of T05, Donic, Yasaka and Stiga users.  I have also tried the same Chinese topsheet with softer sponge variants and the absolute amount of spin that they can produce is significantly less than harder sponge ones that such top players prefer.  This is strictly based on my own experience.  My observation is when executing hardest loops, the hard sponge used by Chinese players does not bottom out as easily as softer ones, so they have an extra gear at the top to add even more pressure/friction to the ball.
What would happen if you gave one of those chinese players used a say LT sound and they did the same stroke? To me a fast shot is not always the spinniest and the timing of a loop type drive at almost before the top of the bounce will go like a rocket becuase of two things 
1. the timming of the shot (as in hitting the ball early so it is already back to the other side before another ball that has been hit latter (so in some case if you hit the ball 3 inches back +the ball has to go 3inche forward to get back to the place where the other person hit it = therfore 6 inches faster per time factor
2. impact from the bat and speed at the right moment


Yes, I have done that many times by switching setups with them or ask them to use different setups.  To answer your question directly:  A looping stroke designed for firm-sponge Chinese smooth rubbers will not work with something like LT Sound.  These visiting Chinese players will adjust their strokes quite a bit after hitting a few balls lightly with the new setups and find the one that works. 
One of the players I played with frequently was Ma Lin's former training partner.  He tried many of our club members' paddles at their request.  When he used Euro or Japanese rubbers he could make a louder cracking sound when looping than anyone I know, indicating he was getting exceptional contact with every loop.  He was also able to use a penhold pips out setup and tried to serve and play like Liu Guoliang.  There's little doubt in my mind a top player of his caliber could use non-Chinese inverted rubbers effectively if he wishes.  BTW, his backhand rubber was Nittaku Hammond Pro Alpha 2.2mm.


Posted By: bluebucket
Date Posted: 04/06/2011 at 6:39pm
Originally posted by debraj debraj wrote:

then that's an exceptional chopper... and i will push that ball. Angry


but truely... you need that peak hand speed only for a 50th of a second or so. and in general, (taking away that 137 rps)... i proves in general you don't essentially need help from blade angle to lift an underspin!! 

How do we explain being able to return a loop that's moving at twice the revs per second as a chop is........with a punch block where the blade isn't moving up or down at all :) all the while pretty much killing the spin dead


Posted By: silverhair
Date Posted: 04/06/2011 at 6:50pm
Originally posted by Congoman Congoman wrote:

Originally posted by silverhair silverhair wrote:

Still no web references to why hard sponge generates more spin than soft sponge?  


If you are really into it, knock yourself out...

http://adsabs.harvard.edu/abs/1953Natur.172..169L

A study from 1953 that is only marginally applicable?  And it doesn't really differentiate much difference at the level we're examining.

Gimme a fricking break.  This proves nothing.

How about something that is really pertinent?  Maybe something recent.  

Your credibility and Speedplay's claims still go unsupported.  


-------------
What if there were no hypothetical questions?


Posted By: roundrobin
Date Posted: 04/06/2011 at 7:42pm
Originally posted by silverhair silverhair wrote:

Originally posted by Congoman Congoman wrote:

Originally posted by silverhair silverhair wrote:

Still no web references to why hard sponge generates more spin than soft sponge?  


If you are really into it, knock yourself out...

http://adsabs.harvard.edu/abs/1953Natur.172..169L

A study from 1953 that is only marginally applicable?  And it doesn't really differentiate much difference at the level we're examining.

Gimme a fricking break.  This proves nothing.

How about something that is really pertinent?  Maybe something recent.  

Your credibility and Speedplay's claims still go unsupported.  


Everything being equal (topsheet, blade, thickness), a regular smooth rubber (not anti) with firm sponge will produce more spin when executed by world-class players than a softer one.  I don't understand why you can't accept this fact from other people's real life experiences... Confused


Posted By: stoic
Date Posted: 04/06/2011 at 8:03pm
In the same enviroment the test will be fair.  They will be tested in an air conditioned enviroment. The top sheets are the same.  If I decide to test with the two Samsonov Alphas the paddles will be the same. I have a robot and a crude laser alignment system and a vice to hold the paddle.  Is that good enough?   This wil just eat into my  practice time.
 
Sounds good, but how will the spin be measured, any design engineers here? I think that your practice time would have to be forfeited to find a conclusive answer, because the differences in spin production maybe too small to guess and human perception is prone to error.
We agree and it is one of those other factors that really determine if the rubber is spiny or not.
I am sure my hard dried out 40 year old paddle will not be as spinny as Rakza 7 soft. 
 
I look forward to your view on the Rakza soft vs hard, it's a rubber I've been considering buying.
 
Actually,  I think it is the spring in the rubber that make the difference.   Any decent rubber will not let the ball slide after the first few micro seconds of contact.  Once the ball pushes in to the rubber there will be enough friction where the ball will not slip relative to the rubber.  If there is no stretching across the surface of the rubber the ball can not be spun any faster than the tangential speed of the paddle since the paddle and the ball are traveling at the same speed.   If this were the case then all spin would be limited by the tangential paddle speed and all rubbers with decent friction would spin the same.

There is a spring action that is across the surface of the paddle that causes the extra spin.  Take a ball and push it against the paddle and then try to move across the paddle without the ball slipping on the surface.  You can see that the ball will stretch the rubber a millimeter or two.  The rubber that snaps back to the undistored position faster provides the most spin.
 
+1 Speed glue is known to increase the spring, and I read somewhere it increases the spin by a percentage over 10. Increase in spring does seem to increase spin from my experience.


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Posted By: silverhair
Date Posted: 04/06/2011 at 8:04pm
Originally posted by roundrobin roundrobin wrote:


Everything being equal (topsheet, blade, thickness), a regular smooth rubber (not anti) with firm sponge will produce more spin when executed by world-class players than a softer one.  I don't understand why you can't accept this fact from other people's real life experiences... Confused



Because it's counterintuitive.  As softer sponge compresses, it gets harder.  The throw would be longer spinning the ball more than just a quick release from harder sponge.

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What if there were no hypothetical questions?


Posted By: bluebucket
Date Posted: 04/06/2011 at 8:22pm
If you ever played a soft sponge on the forehand and tried to loop with it you'll know what happens when a soft sponge compresses..... The ball leaves the bat before the sponge returns and flys straight over the table, spin-less


Posted By: racquetsforsale
Date Posted: 04/06/2011 at 8:22pm
Originally posted by roundrobin roundrobin wrote:

 ... When he used Euro or Japanese rubbers he could make a louder cracking sound when looping than anyone I know, indicating he was getting exceptional contact with every loop...
 
RR,
 
Was the loud crack just the click of those Euro/Jpn speedglue-effect rubbers or was there some wood in it, meaning the Chinese players were driving the ball more, giving a flatter arc?


Posted By: roundrobin
Date Posted: 04/06/2011 at 8:28pm
Originally posted by racquetsforsale racquetsforsale wrote:

Originally posted by roundrobin roundrobin wrote:

 ... When he used Euro or Japanese rubbers he could make a louder cracking sound when looping than anyone I know, indicating he was getting exceptional contact with every loop...
 
RR,
 
Was the loud crack just the click of those Euro/Jpn speedglue-effect rubbers or was there some wood in it, meaning the Chinese players were driving the ball more, giving a flatter arc?


It was a combination of both... And you are correct, they drive the ball extremely hard with an almost straight arm, while trying to give it as low arc as possible.


Posted By: roundrobin
Date Posted: 04/06/2011 at 8:32pm
Originally posted by silverhair silverhair wrote:

Originally posted by roundrobin roundrobin wrote:


Everything being equal (topsheet, blade, thickness), a regular smooth rubber (not anti) with firm sponge will produce more spin when executed by world-class players than a softer one.  I don't understand why you can't accept this fact from other people's real life experiences... Confused



Because it's counterintuitive.  As softer sponge compresses, it gets harder.  The throw would be longer spinning the ball more than just a quick release from harder sponge.


Not if you can swing the blade faster to compress the hard sponge as much as the softer one.  At many pro's level they could "bottom" out a soft sponge rubber too easily, thus robbing them of maximum compression when executing their hardest shots.


Posted By: debraj
Date Posted: 04/06/2011 at 9:17pm
this debate will never end .. because truth is often so counter-intuitive. 

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Posted By: racquetsforsale
Date Posted: 04/06/2011 at 9:47pm

Because the water looks fine, I'm gonna jump in, with questions.

Firstly, regarding "mechanical spin." Is this spin produced by the cupping of the ball by either just the topsheet or both the topsheet and sponge? Can a topsheet that, for the sake of discussion, has absolutely no grip, still produce mechanical spin if it, either alone or along with the sponge, adequately cups the ball? In other words, does the production of mechanical spin rely on the presence of friction?
 
Can it be determined how much of the total spin is grip (friction) applied and how much is mechanically applied?
 
If two topsheets have the same amount of grip, will the one that can also cup the ball more, either by itself or together with the sponge, produce more total spin, because it produces more mechanical spin?
 
Is the total amount of spin then dependent only on the amount of available grip from the topsheet and the degree of cupping from either the topsheet alone or the topsheet together with the sponge? How does the duration of contact, aka dwell time, fit into this? It seems the amount of cupping should be proportional to the dwell time, correct?
 
Is it correct to say that, when both fully compressed down to the wood, a soft and firm sponge of identical thickness will provide the same amount of cupping hence the same amount of mechanical spin? Or does the contact with the wood somehow shortens the contact/dwell time and reduces the amount of mechanical spin?
 
For the same amount of swing effort, shouldn't a softer sponge cup the ball more than a firm sponge because it is more easily compressed to a greater extent, so that it produces more mechanical spin?
 
Whew.
 
 


Posted By: silverhair
Date Posted: 04/06/2011 at 11:02pm
Originally posted by roundrobin roundrobin wrote:

Originally posted by silverhair silverhair wrote:

Originally posted by roundrobin roundrobin wrote:


Everything being equal (topsheet, blade, thickness), a regular smooth rubber (not anti) with firm sponge will produce more spin when executed by world-class players than a softer one.  I don't understand why you can't accept this fact from other people's real life experiences... Confused



Because it's counterintuitive.  As softer sponge compresses, it gets harder.  The throw would be longer spinning the ball more than just a quick release from harder sponge.


Not if you can swing the blade faster to compress the hard sponge as much as the softer one.  At many pro's level they could "bottom" out a soft sponge rubber too easily, thus robbing them of maximum compression when executing their hardest shots.

It won't compress as much because it's hard, and it won't compress as long because the ball will rebound more quickly / shorter dwell.  


-------------
What if there were no hypothetical questions?


Posted By: Jonan
Date Posted: 04/07/2011 at 1:34am
I see lots of potential ways to generate spin...

1.Surface friction/tackines.
2.Dwell time when combined with motion.
3."Catapult" effect from the tension of the pimple structure and/or sponge.

I think if they allowed thicker rubber, softer sponged rubbers would be used because it would let the pros swing harder without negative effects like bottoming out, but as is, harder rubber lets them swing harder and faster which in the end is what makes the spin, the person, not the rubber.

Also you can argue about how things react to spin and how they effects their ability to generate counter spin, like when trying to loop a backspun ball when your ability to generate spin hinders your actual generation of it. Pros don't have so much of this problem because they overpower incoming spin so often with their confident, all out strokes. And then you have pips and anti which are a whole different issue of defining "generating spin" from "causing spin" and how chopping topspin with inverted differs from long pips in that way.


Posted By: Speedplay
Date Posted: 04/07/2011 at 2:24am
Originally posted by silverhair silverhair wrote:


Originally posted by Speedplay Speedplay wrote:

 
Silverhair, I honestly don't feel I need to spend time to back up my claims against some one who refuses to stay on topic. If he was truly interested to learn (instead of trying to teach, which he clearly isn't knowledgeble enough to do) I might consider going in to the technical aspects of this, but when he brings up his "dead" rubber as an example, it shows to me that he don't want to learn anything.
When you make claims such as you have, it is necessary to back up those claims with references.  Failing to provide those references, especially when they have been questioned (as they definitely HAVE been questioned) results in a loss of credibility and the claims being dismissed as unsupported opinion.
So, once again, please provide references to back you claims.  I have stayed on topic, this is my third request.  


I've only noticed it twice, but then again, I've not read the entire tread.

I back up my claims with real life experience.

Still not sure why I should have to find reference that I'm right, as I haven't seen any reference that holds true that shows me wrong. Perhaps yu should start by finding a reference that shows why I'm wrong?

When you loop, the ball digs in to the sponge, and with a harder sponge, you can loop harder/faster before it bottoms out, and the harder/faster you loop, the more spin there will be on the ball, thus giving the harder sponge a greater ability to generate spin.

And to make sure that there is no absurd answers to this, it only holds truth if all other things are being equal regarding the rubber/sponge.

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The holy grail


Posted By: Speedplay
Date Posted: 04/07/2011 at 2:30am
Originally posted by debraj debraj wrote:

)
Originally posted by APW46 APW46 wrote:

.... I know that it is actually impossible for the arm to make the speed required, what actually happens is that the bat angle compensates and lifts the ball.

<div id="isChromeWebToolbarDiv" style="display:none">
sorry which arm speed are we talking about? 137 RPS is the rotational speed on the ball. 
which means for a 40mm ball its 137 * 40 * (pi=3.14)= 17207mm/sec linear speed =17 meters per sec
definitely most of us loopers match it.... and that's why we can actually loop against a backspin with the racket completely over the ball or at least the racket facing little downwards 
.. and the ball hanging below. Which means the angle of the bat doesn't provide any  vertical lift vector (cos theta LOL)  to the ball to lift it or keep it lifted. 
... yeeeeeehhhhhhhh !!! Hug  
now where's my prize for brushing up school maths?  Confused


Debraj, not sure if I get your post, but are you saying that the average club looper is able to reach a speed of 17 metersper sec with their arm?

If so, I find it pretty amazing, cause I recently watched a show called "Sport Science" (not sure how serious they are, but they do seem to take things extremely serious) and they did some experiment concerning different fighter. As a reference, they used a venom snake, and showed that during attack, the snake moved at 2.4-3 m/s. Then they had a Kung Fu fighter ( can't remember what Kung Fu is called when they compete in it, but I do think this guy was the world champion) who was supposed to be the fastest fighter in the world. They measured his hand/arm speed when hitting and he reached 12 m/s with his stroke.

If the average club player is faster then that, then credit to TT players all over the world.

How ever, when looping, we use both arm and wrist, to accelerate the speed of the blade, but I still find it hard to belive that the average club player could reach such speed during a loop.

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The holy grail


Posted By: racquetsforsale
Date Posted: 04/07/2011 at 3:24am
3m/s for a snake's strike sounds really low. I googled but didn't find anything conclusive, but I vaguely remember a show on TV about snakes. It mentioned that a rattlesnake can strike @ 70 miles per hour, which is 27m/s, if not more. A good martial artist can certainly dodge or parry a punch from another, but there is absolutely no way a human can react fast enough avoid a striking rattlesnake, which strikes faster than the eye can see.


Posted By: APW46
Date Posted: 04/07/2011 at 3:39am
Originally posted by debraj debraj wrote:

)
Originally posted by APW46 APW46 wrote:

.... I know that it is actually impossible for the arm to make the speed required, what actually happens is that the bat angle compensates and lifts the ball.


sorry which arm speed are we talking about? 137 RPS is the rotational speed on the ball. 

which means for a 40mm ball its 137 * 40 * (pi=3.14)= 17207mm/sec linear speed =17 meters per sec

definitely most of us loopers match it.... and that's why we can actually loop against a backspin with the racket completely over the ball or at least the racket facing little downwards 

.. and the ball hanging below. Which means the angle of the bat doesn't provide any  vertical lift vector (cos theta LOL)  to the ball to lift it or keep it lifted. 

... yeeeeeehhhhhhhh !!! Hug  



now where's my prize for brushing up school maths?  Confused
 I'm talking about the higher end of heavy chop, and I don't need maths, just a lifetimes experience to know that any attempt to lift it with a closed bat ends in the ball being dumped in the net. Infact its one of the most common mistakes of intermediate/lower rated players that they believe heavy chop has to be competed with. Can I ask how you loop float? decrease you bat speed accordingly, or close your bat angle?
 


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The Older I get, The better I was.


Posted By: Speedplay
Date Posted: 04/07/2011 at 3:47am
http://www.livedash.com/transcript/sport_science-(the_deadliest_strike)/3774/CSNBA/Sunday_August_1_2010/394472/

Scroll down to ~37, where the snake vs boxer begins.

This is a link to a transcript from another one of their shows, where they test a rattlesnake vs a boxer. The rattlesnake strikes at 15ft/s=4.572m/s. The boxer strikes 30ft/s=9.144m/s.

Can't find any clips, or links to the show I watched, sorry.

From the page:

00:35:52 >> In the sweet science of boxing, the most devastating punches aren't always the hardest.
00:36:06 Sometimes it's the blinding strikes mmt boxers spend a large percent able of their training focus specifically on hand speed.
00:36:19 But hour fast are the fists flying?
00:36:22 And how does the hand speed of a champion boxer compare to one of the animal kingdom's fastest strikes?
00:36:31 >> We rigged a real ringer.
00:36:34 It's not boxer versus boxer.
00:36:37 It's boxer versus snake.
00:36:39 And may the best species win.
00:36:44 >> Going against each other toe to tail, we are bringing in two performers in their prime.
00:36:52 This this corn e, representing the animal kinger, the western diamondback rattlesnake.
00:37:04 This viper killed more people in northern america than any other snake.
00:37:10 And in our corner, is a fight horse is known to have some of the fastest hands in boxing.
00:37:16 Chad dawson.
00:37:22 Chad entered the ring more than 25 times and left victorious every time with 60% of those wins by knockout.
00:37:34 We will test the rattle snake first.
00:37:42 We have never brought something so potentially lethal into the lab.
00:37:46 So the snake wranglers calls for a monday toir sayty meeting.
00:37:53 >> It destroys blood and tissue.
00:37:59 You get major tissue damage.
00:38:03 A snake like this, you are going to be in the hospital for quite some time.
00:38:09 >> The snake wranglers will position a balloon at two feet away and we will be looking at the snake's top speed as it lunges to the target.
00:38:26 We will capture the tight byte to determine how fast it moved.
00:38:31 >> They have an extremely fast strike.
00:38:35 It's like an explosion.
00:38:41 >> It's time to find out who's faster.
00:38:46 A rattlesnake or a boxer.
00:38:49 First up, the rattler.
00:39:21 So how fast is this deadly strike?
00:39:25 Analysis reveals a top speed of 15 feet per second.
00:39:31 That incredible acceleration is the equivalent of going 0 to 60 in under three seconds.
00:39:44 Animal kingdom's ringer is fast.
00:39:45 But now it's time to bring in our ringer.
00:39:49 Undefeated light heavyweight champion chad dawson.
00:40:01 >> Chad dawson, you have some of the fastest nands boxing.
00:40:05 How do you punch so quickly?
00:40:07 >> It's like a rattle snake.
00:40:10 A rattle snake, you want to be ready to strike.
00:40:16 And when you make a move, the snake reacts.
00:40:18 You want to be loose and aggressive.
00:40:24 >> For this experiment, our high speed camera will time chad's single punch to our crash test dummy.
00:40:36 We will read the exact moment chad's first makes contact.
00:40:42 >> See that real explosive energy.
00:40:45 Just like that.
00:40:46 Coiled up snake.
00:40:47 Whack.
00:40:51 >> So can chad outstrike one of nature's fastest strikes?
00:40:56 Find out when "sport science" returns.


I'm kind enough to cut out the advertisment, so here comes the rest of it:

00:44:20 >>> For a boxer, fast hands mains the difference mean taking home hardware and taking a hard fall.
00:44:27 So we want to know just how fast an elite boxer can really strike.
00:44:33 And how does the bocker's hands speed compare to one of nature east fasters strikers.
00:44:41 To test first versus fang, we started with a predator with a nasty rep constitution.
00:44:50 The western diamondback rattlesnake.
00:44:53 We measured a strike speed of 15 feet per sec.
00:44:58 So can this boxer, world heavyweight champion chad dawson, strike as quickly as this rattle snake?
00:45:08 Chad is willing to give it a shot.
00:45:23 >> Yeah.
00:45:27 >> So how fast was that punch?
00:45:32 Could chad's firsts will moving faster than the speed of fangs?
00:45:41 To the naked eye, this contest is way too close to call.
00:45:46 And since it's over in a heart beat, to determine the winner, our motion capture technology gives us on inside look.
00:46:01 Chad's hands speed is a product of olympics.
00:46:06 As he throws his fists, chad snaps his shoulder to create momentum that gains velocity as it gets down the arm.
00:46:21 Chad cracks his first at an incredible 30 feet per second.
00:46:26 Amazing lie, that is twice as fast as the snake.
00:46:31 If the snake is faster than a tricked out sports car, chad accelerates faster than a race car.
00:46:45 Faster that a top fuel dragster and even faster than an f-14 fighter jet.
00:46:53 All though chad gave the snake a beatdown, he still got a healthy respect for his rep tillan adversary.
00:47:05 >> He's faster than my opponents.
00:47:08 >> This is something else.
00:47:10 The snake is a one hit wonder.
00:47:13 It will only strike one.
00:47:15 Chad with obliterate with a flurry of punches.
00:47:21 Try to guess how many punches he throws in five seconds.
00:47:31 Our phantom high speed camera reveals that chad threw 26 punches in five seconds.
00:47:42 To put that in perspective, the same amount of time drew brees throws a dart down field, chad dawson unleeches five hammers punches and that kind of speed will leave anyone totally rattled.
00:48:04 >> Told you I was faster than a sna >>> I'M pete McLeod.
00:49:08 [ Murmuring ].


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The holy grail


Posted By: Jonan
Date Posted: 04/07/2011 at 4:01am
Originally posted by racquetsforsale racquetsforsale wrote:

but there is absolutely no way a human can react fast enough avoid a striking rattlesnake, which strikes faster than the eye can see.


As a person who has hunted and killed some 40+ poisonous snakes, including rattlesnakes, using only a machete and a brush axe, it can be done, they aren't that fast. The only snakes that bit me were ones I kept as pets.


Posted By: debraj
Date Posted: 04/07/2011 at 4:13am
Originally posted by APW46 APW46 wrote:

Originally posted by debraj debraj wrote:

)
Originally posted by APW46 APW46 wrote:

.... I know that it is actually impossible for the arm to make the speed required, what actually happens is that the bat angle compensates and lifts the ball.


sorry which arm speed are we talking about? 137 RPS is the rotational speed on the ball. 

which means for a 40mm ball its 137 * 40 * (pi=3.14)= 17207mm/sec linear speed =17 meters per sec

definitely most of us loopers match it.... and that's why we can actually loop against a backspin with the racket completely over the ball or at least the racket facing little downwards 

.. and the ball hanging below. Which means the angle of the bat doesn't provide any  vertical lift vector (cos theta LOL)  to the ball to lift it or keep it lifted. 

... yeeeeeehhhhhhhh !!! Hug  



now where's my prize for brushing up school maths?  Confused
 I'm talking about the higher end of heavy chop, and I don't need maths, just a lifetimes experience to know that any attempt to lift it with a closed bat ends in the ball being dumped in the net. Infact its one of the most common mistakes of intermediate/lower rated players that they believe heavy chop has to be competed with. Can I ask how you loop float? decrease you bat speed accordingly, or close your bat angle?
 

if your theory would work... it would never be possible to loop any backspin with closed bat angle independent of the rps.

well I make that common mistake also thinking heavy chops can be competed with.... fortunately i do it successfully just like so many others.

loop float? are you talking about the stroke that beginners and some oddball players do, trying to open the face of racket and brush upwards? ... no i don't have that stroke. while looping, the widest possible angle i use is 90degree (i.e blade face perpendicular to floor) ..but mostly less, with blade facing down, and still coaches shout.... "forward, forward, not upward!!"

i don't understand why you are even thinking this way... because its so evident. see this video os timo boll and joo se hyuk ...is the racket angle closed or open. given then joo's lp is delivering very heavy backspin (originally generated by timo's spinny tenergy loops).

  http://www.youtube.com/watch?v=eMCPWfgpJ7c - http://www.youtube.com/watch?v=eMCPWfgpJ7c

however, i take back the idea of speed required 17m because further refining that.. i think when the ball touches the blade, it initially decelerates a bit due to frictio... losing a significant percentage of its rps..before the blade speed catches up . which should require less speed in hand movement.



-------------
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Posted By: mercuur
Date Posted: 04/07/2011 at 4:21am
In earlier days there was an attraction at fairs ; the swingmill. Haven,t seen it since long but sitting in a little car that was jointed to a rotating swingmill with a bearing and a rope to the swingmill you had to pull the car close to the swingmill against the outward g-forces. Then when the rope was left loose the car would swing outward and accelerate suddenly and intensively by the g-force reaching a far higher speed for the car as for the main swingmill (that lowers its rotation then by a little allthough that was unnoticable in this case). I regard that as  energy flow ( the main swing looses energy and the car gains) because it is accelleration without direkt use of muscleforce. The energy was deliverd earlier stage by pulling the car to a shorter distance to the swing and it was released with letting the rope go.

This principle is also used by - for instance - a kung fu fighter (with the wristjoint as the bearing and the muscles holding the hand bend backwards as the rope until last moment before contact.) So it,s imposible that arm and hand have a (the same) maximum speed. A kungfu fighter hitting through a pile of stones uses the ame principle to let the energy flow outward to his hand (accellerating gaining energy) but his arm loosing energy allready before contact is made (as it flows outward to the hand). That,s accelleration by - timed -relaxation.
Tabletennisplayers also do this. This accelleraton is taking only a fraction of time compared with accellerating the arm. So to know the speedof the blade t contact it maes a difference what moment of contact you look at. Making contact it is lower and at the end of contact it will be higher...Accellerate through the ball is how chinese coaches refer to this as with chinese rubbers with not much katapult that,s where the katapult (as a sudden accelleration) has to come from...from the player instead of the rubber.

Interesting thing with the kung fu fighter is that this prevents his hand to get hurt also.
The trick is to not have the highest speed for the hand at making contact and do the trick/technicque - accellerating same time as when the contact is made. The resistance of the stone the hand won,t accellerate as easy and as much but the energy will still flow outward to the stone while his arm stops. The stroke has to be short with the accelleration as concentrated as possible and the aim is to generate vibes in the stones in a way that they break. Hitting through with the whole arm wouldimmediatelydampen the generated vibrations (energy) and result in a sour hand and the stones not broken. Not as much power needed for that just skill, relaxation and timing.

A ping pong ball is different because it is much lighter it won,t give the resistance of stones preventing the bat from accelerating suddenly during contact. How concentrated the accelleration is (during contact which is short) is more or just as relevant as "bladespeed on contact". too much of that you don,t even make good contact.



Posted By: racquetsforsale
Date Posted: 04/07/2011 at 5:01am
Originally posted by Jonan Jonan wrote:

Originally posted by racquetsforsale racquetsforsale wrote:

but there is absolutely no way a human can react fast enough avoid a striking rattlesnake, which strikes faster than the eye can see.


As a person who has hunted and killed some 40+ poisonous snakes, including rattlesnakes, using only a machete and a brush axe, it can be done, they aren't that fast. The only snakes that bit me were ones I kept as pets.


Jonan,

You the man. I absolutely abhor snakes. But back to the off topic discussion. If you stick your hand in front of a rattlesnake and it strikes, there's no way you can react and pull back fast enough to avoid the bite. Emphasis on react. The snake, however, might miss. There's no doubt that if you strike first, you might beat the snake to the punch, but purely reacting to it, meaning it has to strike first before you take action---no way.

Just in case you can, though, I bet a lot of people will pay money to see it.


Posted By: racquetsforsale
Date Posted: 04/07/2011 at 5:29am
Originally posted by Speedplay Speedplay wrote:

......


Actually found some scholarly text on rattlesnake strikes. You're right after all. I was mislead by the difference in strike distance between a punch and a snake strike.Embarrassed


Posted By: davidz
Date Posted: 04/07/2011 at 10:54am
The relationship between spin and hardness of rubber is not linear.  It is hard to say which one has more spin.  Dwell time is a critical factor for spin.  When a rubber is too hard or too soft, it does not have much spin.
 
I always play hard rubber, it often has more spin when I make it softer. However, when it is too soft, the spin gets worse.  
 


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PG7 (Skyline 2, LKT XP)
YEO (Skyline 2, Skyline 3)


Posted By: racquetsforsale
Date Posted: 04/07/2011 at 11:07am
Originally posted by racquetsforsale racquetsforsale wrote:

Because the water looks fine, I'm gonna jump in, with questions.

Firstly, regarding "mechanical spin." Is this spin produced by the cupping of the ball by either just the topsheet or both the topsheet and sponge? Can a topsheet that, for the sake of discussion, has absolutely no grip, still produce mechanical spin if it, either alone or along with the sponge, adequately cups the ball? In other words, does the production of mechanical spin rely on the presence of friction?
 
Can it be determined how much of the total spin is grip (friction) applied and how much is mechanically applied?
 
If two topsheets have the same amount of grip, will the one that can also cup the ball more, either by itself or together with the sponge, produce more total spin, because it produces more mechanical spin?
 
Is the total amount of spin then dependent only on the amount of available grip from the topsheet and the degree of cupping from either the topsheet alone or the topsheet together with the sponge? How does the duration of contact, aka dwell time, fit into this? It seems the amount of cupping should be proportional to the dwell time, correct?
 
Is it correct to say that, when both fully compressed down to the wood, a soft and firm sponge of identical thickness will provide the same amount of cupping hence the same amount of mechanical spin? Or does the contact with the wood somehow shortens the contact/dwell time and reduces the amount of mechanical spin?
 
For the same amount of swing effort, shouldn't a softer sponge cup the ball more than a firm sponge because it is more easily compressed to a greater extent, so that it produces more mechanical spin?
 
Whew.
 
 


Can someone answer these questions? Maybe they will end the debate.


Posted By: debraj
Date Posted: 04/07/2011 at 1:25pm
Originally posted by davidz davidz wrote:

The relationship between spin and hardness of rubber is not linear.  It is hard to say which one has more spin.  Dwell time is a critical factor for spin.  When a rubber is too hard or too soft, it does not have much spin.
 
I always play hard rubber, it often has more spin when I make it softer. However, when it is too soft, the spin gets worse.  
 

finally someone i can completely agree with !! :)


-------------
729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
http://youtu.be/y9y9nE9g778" rel="nofollow - vid1
http://youtu.be/xqNy786yGOs" rel="nofollow - Vid 2


Posted By: Congoman
Date Posted: 04/07/2011 at 1:33pm
It's much more productive if you consider the thickness of the rubber instead of hardness. The thicker the rubber the more spin it will produce, period.

Also, when an opponent's backspin comes over, it is your TOP spin. The reason it's hard to lift is because it is hard to get a good grip on the ball.  The example on top of 17m/s is merely the speed to match the spin of the incoming ball at 150rps, that only breaks even...you'll have to 34m/s to get the ball back at 150 rps.  It's not as simple as matching the spin of incoming, but rather maximize your grip on the incoming ball so you can change the spin and return it back.


Posted By: debraj
Date Posted: 04/07/2011 at 2:46pm
Originally posted by Congoman Congoman wrote:

It's much more productive if you consider the thickness of the rubber instead of hardness. The thicker the rubber the more spin it will produce, period.

Also, when an opponent's backspin comes over, it is your TOP spin. The reason it's hard to lift is because it is hard to get a good grip on the ball.  The example on top of 17m/s is merely the speed to match the spin of the incoming ball at 150rps, that only breaks even...you'll have to 34m/s to get the ball back at 150 rps.  It's not as simple as matching the spin of incoming, but rather maximize your grip on the incoming ball so you can change the spin and return it back.


and why would you 'change' the spin while looping against backspin?


-------------
729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
http://youtu.be/y9y9nE9g778" rel="nofollow - vid1
http://youtu.be/xqNy786yGOs" rel="nofollow - Vid 2


Posted By: zeio
Date Posted: 04/07/2011 at 3:05pm
Not by any means an attempt to end the debate, but below I would like to share my thoughts and in a way address some of the questions raised.

It is my understanding that the spin or, more technically, the rotation produced on a table tennis ball in flight comes from an applied force that does not go through the center of gravity.  This applied force is referred to as the " http://www.brianmac.co.uk/biomechanics.htm - eccentric force ."

It is also a well established fact that the topsheet of an inverted rubber(whether it be tacky or grippy) is what provides the grip.  The real beauty, however, lies beneath the surface.  Those lines of pips under the topsheet come into play when an inward force is present, which compresses the pips and in turn pushes them into the sponge, creating gutter-like depressions.  Since there are empty aisles of space between the lines of pips, these underlying gutters would stretch both the topsheet and sponge thus increasing the surface area that is in contact with the ball for the force to act on.  Depending on the direction of the force applied, the energy stored from the compression would release and reflect on the ball either as translation(movement), rotation or both.

In a sense, the longer the pips are, the more the topsheet stretches; the tighter the pips are arranged, the more the sponge is engaged; the thicker the sponge, the more the speed and spin in return.  This sort of explains why the ITTF has imposed various regulations on rubber thickness and pimple dimensions etc.  For anyone interested, look under "B. Quantitative Criteria" of the http://docs.google.com/viewer?url=http%3A%2F%2Fwww.ittf.com%2Fstories%2Fpictures%2FT4RacketCoverings08_2010.pdf - Technical Leaflet T4 .

And here is another catch.  Since the ITTF's imposed limits on topsheet are, (clearing throat), quite limiting, manufacturers have resorted to raising the hardness of the topsheet and/or sponge to make up for the difference in thickness.  This poses a challenge for some players as the rise in hardness requires a higher amount of force be generated to exploit the heightened speed and spin potential.  So it is not uncommon that some may find the T05 fx has better speed and spin than the T05 of same thickness.

-------------
Viscaria FL - 91g
+ Neo H3 2.15 Blk - 44.5g(55.3g uncut bare)
+ Hexer HD 2.1 Red - 49.3g(68.5g 〃 〃)
= 184.8g


Posted By: roundrobin
Date Posted: 04/07/2011 at 3:09pm
Typical scenario at our club when a 1900-2000 level player takes lesson from coaches like Gao Jun or Crystal for the very first time:  He shows up with a clicky looping setup with modern maximum sponge inverted rubbers and proceeds to loop strong topspin to the coach.  His loops look great, sound great, and have a nice arc to them.  The coach says:  "Loop harder." And he does, to the best of his ability... He sweats profusely.  "Something is wrong," the coach says, "your loops are too easy to block".  She inspects his rubbers closely.  "This is too soft... No wonder you are not producing enough spin."  He comes back for the next lesson with firmer version of the same rubbers and proceeds to perform the same loops.  "Aaaahhh...Much better!"  The coach says.


Posted By: debraj
Date Posted: 04/07/2011 at 3:32pm
Originally posted by roundrobin roundrobin wrote:

Typical scenario at our club when a 1900-2000 level player takes lesson from coaches like Gao Jun or Crystal for the very first time:  He shows up with a clicky looping setup with modern maximum sponge inverted rubbers and proceeds to loop strong topspin to the coach.  His loops look great, sound great, and have a nice arc to them.  The coach says:  "Loop harder." And he does, to the best of his ability... He sweats profusely.  "Something is wrong," the coach says, "your loops are too easy to block".  She inspects his rubbers closely.  "This is too soft... No wonder you are not producing enough spin."  He comes back for the next lesson with firmer version of the same rubbers and proceeds to perform the same loops.  "Aaaahhh...Much better!"  The coach says.


yes that's very plausible. i have realized this when i tried blitz and thor's on 2 sides of same set-up.

the feeling of spin was much higher with blitz... because of softer sponge with huge hold time, and the ball curve path was nice. The guy blocking was arguably the best blocker in club, and he was blocking pretty well. But when i changed to with thor's ...he found it way more difficult to block than blitz... although i didn't feel the ball hold as much with thors.




-------------
729-F1||Rhyzm-P(FH)|| Rasant Grip orRhyzm-P max(BH)
http://youtu.be/y9y9nE9g778" rel="nofollow - vid1
http://youtu.be/xqNy786yGOs" rel="nofollow - Vid 2


Posted By: Congoman
Date Posted: 04/07/2011 at 4:30pm
Originally posted by debraj debraj wrote:


and why would you 'change' the spin while looping against backspin?


In the case of looping a backspin, you are not necessarily changing the spin of the ball, rather making a trajectory so the ball travels over the net.

Or in another word, you are trying to change the direction the incoming ball travels when bouncing off a stationary rubber. You would hear coaches say "lift the ball" rather than "counter the spin".



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