I notice that top of the line rackets have thin/slim shaft. What's the theory behind of having thin shaft as oppose to thick one? The original Yonex Blacken B-8100 has a very thin shaft. So are the Swing Power and Ti-10, though not as thin as the B-8100.

u siwng it faster. or something like that eniwei.

This question also has to do with the material used in the racquet...

You can have a slim shaft and use graphite, but I garauntee that it will snap on you... those are flawed designs that the manufacturers toyed with, and are trying to change with higher strength, materials.

Obviously if you made the racquet of steel... it would be too heavy for most players.
So what Yonex did was go back, and analyze the structure, and composition of the graphite itself...
With new technology used to layer the graphite, and wrap it around the shaft, also a remixing of the actual composition of the graphite... they came up with Ultra High Modulous graphite or some BS like that...
Anyways.. the result is that they came up with something very strong, and very stiff, that has the similar if not the same characteristics as steel did.

Remember... if it was too thin, the racquet would snap very easily... like if you had a glass table.. if it's too thin, everything you put on it would break the table...
The slimness of the shaft itself I do not believe has anything to do with power at all.
It more has to do with the flex of the shaft, and racquet head, and the player... if it's a strong player, with good wrist/arm combination with a stiff shaft, they would be a killer combo... a strong player, and a flexible shaft do not mix at all... as they generate so much momentum, and torque off their swing the racquet head literally lags behind, and will not hit the shuttle properly.

Back to the slimness... if they made the graphite too thick, then it would not flex much at all, thus giving the same effect as if it were too thin... breakage.

I think what you're referring to in general is whether or not the shaft design has anything to do with power... and I've answered most of that to my knowledge...
except one thing.

The slimmer the shaft, the more aerodynamic the racquet shaft will be, thus leading to faster swing speed... Yonex found earlier with the Widebody frame, that the frame structure was compromised, and thus broke around 12 o'clock... I didn't have that problem... as mine just obliterated off the force of my shot, breaking into several pieces, and string all over...

Anyways... Yonex sought to change that, and explored options with making the shaft slimmer as you see now... and whether or not it's sucessful design, only time will tell. I must say, even though the racquet shaft is slimmer giving me better aerodynamics through the air, it will definitely break easier... as I've seen them snap on their shafts before.

One other thing I should mention before I end this and go to sleep, is that you should take an example from tennis...
Would you rather have a tennis racquet to play our beloved sport?
Their shaft is fairly thick... thus it needs to support the head better... anyways... the rest of it, I think might have to do with the laws of badminton... only allowing certain dimensions to racquets... you might want to read up on this as well.
Pretty interesting topics you chose.

:) :( :o :D ;) :cool: :P :? :X

Supposed to reduce air resistance

ya, simple. less drag.

nice explanation kelvin. sure to get top marks if you handed something like that for phys.

A thin shaft reduces weight on the bottom end of the racquet making it more head heavy. This will help to generate more power on your swing hence the name swing power

Agreed although some thin shaft rackets like the original Cab 20 & 21 are balanced in weight distribution.

well ISO is used in the swing power design and an ISO frame is inheritly head heavy already even without a 7mm shaft.