Concavity on the blade. WHAT's FOR?

igorponger, what manufacturers and who is telling them to make a concave rubber?

Its been mentioned the Chinese were using concave blades and matching sponge to exceed the 4mm sponge and topsheet rule at some stage in the past, recent past I guess. That's brought about the more stringent thickness testing

JacekGM wrote: tt4me wrote: igorponger, what manufacturers and who is telling them to make a concave rubber? Who came up with this lame idea?   The OP speaks about the blade (wood)

I understand what igorponger is suggesting. It wouldn't be hard to make something similar; such as a tiered outer ply. All you would need is a good router. In this case, at a predetermined radius you could have a thicker sponge, but from the outside of the racket, everything would look kosher.

the_theologian wrote: I understand what igorponger is suggesting. It wouldn't be hard to make something similar; such as a tiered outer ply. All you would need is a good router. In this case, at a predetermined radius you could have a thicker sponge, but from the outside of the racket, everything would look kosher.

Because everyone wants a blade with a smaller sweet spot?

Baal wrote: the_theologian wrote: I understand what igorponger is suggesting. It wouldn't be hard to make something similar; such as a tiered outer ply. All you would need is a good router. In this case, at a predetermined radius you could have a thicker sponge, but from the outside of the racket, everything would look kosher. Because everyone wants a blade with a smaller sweet spot?

jrscatman wrote: would the concave surface give you more chance to stretch the top sheet? This is what speed glue used to do right?

Nice idea! although it would be hard to put just enough speed glue to expand the topsheet such that it would look flat. Too little and it would look concave


Edited by davidwhang - 12/31/2013 at 6:10am

It makes sense for a few reasons, the blade would be more stable in the way it flexes (not so much side to side and diagonal flexing. The sweet spot could be tuned to be practically non noticeable. As the outer areas that are thicker would be naturally faster and could be that the entire surface plays the same speed. on a fully Ayous or basswood 7 ply you wouldn't have to worry about the wood changing character. The design is sound, it's just not legal. You wouldn't need any tools to do it, some hours and you could do it by hand. There's plenty of cheap manual hours on offer in China

Edited by bluebucket - 12/31/2013 at 6:43am

bluebucket wrote: Its been mentioned the Chinese were using concave blades and matching sponge to exceed the 4mm sponge and topsheet rule at some stage in the past, recent past I guess. That's brought about the more stringent thickness testing

Mentioned where?  The thickness testing was caused by extreme boosting.

ttvet86 wrote: Baal wrote: 2.04.01  The racket may be of any size, shape or weight but the blade shall be flat and rigid. I work for a regulatory agency, and whenever a rule has the word "shall" in it, then it is not absolute.  A big "gray area", so to speak.  If the rule said that the blade must be flat and rigid, then there is no wiggle room.  Just my 2 cents

ttvet86 wrote: Baal wrote: 2.04.01  The racket may be of any size, shape or weight but the blade shall be flat and rigid. I work for a regulatory agency, and whenever a rule has the word "shall" in it, then it is not absolute.  A big "gray area", so to speak.  If the rule said that the blade must be flat and rigid, then there is no wiggle room.  Just my 2 cents

It is interesting, and I found something about this on Wikipedia.  "Legislative acts and contracts sometimes use "shall" and "shall not" to express mandatory action and prohibition. However, it is sometimes used to mean "may" or "can". The most famous example of both of these uses of the word "shall" is the United States Constitution. Claims that "shall" is used to denote a fact, or is not used with the above different meanings, have caused discussions and have significant consequences for interpreting the text's intended meaning.^{[8]'     http://en.wikipedia.org/wiki/Shall_and_will}

The intent of the ITTF rule is clear, though, since they use the "shall" construction for all sorts of other rules that they currently enforce vigorously, including, for example, the size of the table and the height of the net.  I think we can all agree these things are not optional.  Also, looking at the following,

2.04.01  The racket may be of any size, shape or weight but the blade shall be flat and rigid. [bold added]

It is clear that they are making a distinction here between things that are optional and things that are mandatory, using the word "shall" for the later. So if you showed up at an ITTF event with a clearly non-flat paddle, they would disallow it. 

bluebucket wrote: Its been mentioned the Chinese were using concave blades and matching sponge to exceed the 4mm sponge and topsheet rule at some stage in the past, recent past I guess. That's brought about the more stringent thickness testing

I tried Google translate.  The text did not translate well.  There are probably too many idioms.

WOW Zeio!  Amazing.  Now I am forced to start the new year by having to apologize to Igorponger for calling his comments a fever dream!  (Before long though we will here more from him about the carnal sex-crazed Tenergy vampiress--at least I hope).

It seems like the chronology is like an arms race: 

Glue ban---- followed by invention of boosting --- ITTF responds to boosters by fancy methods of measuring thickness ----in response to that, people are "gauging" blades because they know ITTF measures thickness around outer margin of rubber.  

I still can't imagine the advantages outweigh disadvantages.  But if people are doing it.....