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Adrupert
01-06-2008, 01:01 PM
Might be a nooby question but I don't get how the Microgel Prestige can have such a lower swingweight than the K-six one when you look at the specs they are almost identical. Can anyone tell me why?

Head Size:
93 sq. in. / 600 sq. cm.
Length: 27 inches / 69 cm
Strung Weight: 12.2oz / 346g
Balance: 7pts Head Light
Swingweight: 328
Stiffness: 63
Beam Width: 19 mm Straight Beam


Head Size:
95 sq. in. / 613 sq. cm.
Length: 27 inches / 69 cm
Strung Weight: 12.3oz / 349g
Balance: 8pts Head Light
Swingweight: 340
Stiffness: 69
Beam Width: 22 mm Straight Beam

Zachol82
01-06-2008, 01:20 PM
Well the Microgel's static weight is already lower. I'm not sure if the stiffness and beam width would affect the swingweight...but I'm sure it does somehow.

Adrupert
01-06-2008, 01:27 PM
Well the Microgel's static weight is already lower. I'm not sure if the stiffness and beam width would affect the swingweight...but I'm sure it does somehow.

It must, because while the static weight is lower, the balance is also lower which should counter the effects of a a lower weight on swingweight.

Agent Orynge
01-06-2008, 03:09 PM
The balance of a racquet only tells you where the average weight of the racquet is, but not how the weight is distributed. Swingweight is not calculated from the very butt of the racquet, but from a point somewhere along the handle. Without being a physics expert myself, my best guess as to why this is done is because the center of the centrifugal force is somewhere nearer the top of your hand. Of course, I may be totally off base here and anyone who know's better is more than welcome to correct and/or harangue me for doling out false information.

At any rate, if the distribution of weight below the balance point is uneven, with a better part of the weight being below the point from where the swingweight is measured, that might account for a big discrepancy in swingweight between two otherwise similar frames.

RestockingTues
01-06-2008, 05:42 PM
The swing weight of the six one is higher because the head is bigger, and the beam width is thicker. That itty bitty 2 inch sq. and the 3 mm will account for that much more air resistance.

[d]ragon
01-06-2008, 05:50 PM
lower static weight + different weigh distributions

Bud
01-06-2008, 05:52 PM
The swing weight of the six one is higher because the head is bigger, and the beam width is thicker. That itty bitty 2 inch sq. and the 3 mm will account for that much more air resistance.

Bingo! Weight distribution and air resistance will change the SW a bit. Static weight and balance are the biggies, though.

Agent Orynge
01-06-2008, 09:50 PM
Air resistance is factored into swingweight? Alright, I'll bite; What's the formula for calculating swingweight?

Midlife crisis
01-06-2008, 11:22 PM
Swingweight is calculated by clamping a racquet into a Babolat RDC machine. The racquet is then rotated through an arc with the center of axis 10 cm up from the butt of the racquet. The swingweight is really a measure of inertia around the center of rotation, and does not take air resistance into account.

As to why the swingweights are different, it depends on the mass distribution. For instance, you can have a racquet where the weight is predominantly at both ends of the racquet, and one with the weight predominantly at the center of the racquet. These may well have the exact same static weight and balance, but the swingweight will vary significantly, with the racquet that has more weight distributed towards the ends of the racquet having the higher swingweight.

RestockingTues
01-06-2008, 11:24 PM
Swingweight is calculated by clamping a racquet into a Babolat RDC machine. The racquet is then rotated through an arc with the center of axis 10 cm up from the butt of the racquet. The swingweight is really a measure of inertia around the center of rotation, and does not take air resistance into account.

As to why the swingweights are different, it depends on the mass distribution. For instance, you can have a racquet where the weight is predominantly at both ends of the racquet, and one with the weight predominantly at the center of the racquet. These may well have the exact same static weight and balance, but the swingweight will vary significantly, with the racquet that has more weight distributed towards the ends of the racquet having the higher swingweight.

Double fault :oops:

RestockingTues
01-06-2008, 11:25 PM
Thanks for the reply MC, I learned something new today :D

Agent Orynge
01-06-2008, 11:51 PM
Yes, thanks Midlife for double-tapping my point.

Midlife crisis
01-07-2008, 12:05 AM
Hey, I found a couple of pictures of a Babolat RDC in action measuring swingweight:

http://av.warehousesports.com/tw/Features/RDC/photo3-RDCswingweight.JPG

http://www.photostringer.com/images/Babolat_Racquet_Diagnostic_Center_09.jpg