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View Full Version : Racquet Experts: Help with quick calculation, please.


Winners or Errors
08-18-2011, 04:06 PM
Well, TW shipped me the two matched 4D 100's I requested, but the specs on the sticker are unstrung. Can someone help with the conversion to the strung specification?

Here's what they both measure, unstrung, with the plastic and vibration dampener on the grip.

Weight: 11.3 oz (I know that equals 320g, so assuming the plastic wrap weighs <1g I'm guessing the gross weight is roughly 334g/11.8oz with the dampener)
Balance point: 12 1/8" (Measured from butt? That's 11pts head-light, right, though I have no idea how much the plastic and dampener add to the handle)
SW: 277

Any help will be appreciated. Not really sure how to calculate the distribution of string mass to arrive at balance point and SW.

Winners or Errors
08-19-2011, 04:20 PM
Bump. No one can just dash this out?

TennisMaverick
08-19-2011, 04:47 PM
Well, TW shipped me the two matched 4D 100's I requested, but the specs on the sticker are unstrung. Can someone help with the conversion to the strung specification?

Here's what they both measure, unstrung, with the plastic and vibration dampener on the grip.

Weight: 11.3 oz (I know that equals 320g, so assuming the plastic wrap weighs <1g I'm guessing the gross weight is roughly 334g/11.8oz with the dampener)
Balance point: 12 1/8" (Measured from butt? That's 11pts head-light, right, though I have no idea how much the plastic and dampener add to the handle)
SW: 277

Any help will be appreciated. Not really sure how to calculate the distribution of string mass to arrive at balance point and SW.

Add 16-18 grams and move the balance 3 pts, approx.

UWBTennis
08-19-2011, 05:25 PM
TM is mostly right, as for swingweight you would need TW method for measuring that, check here: http://twu.tennis-warehouse.com/learning_center/howto_swingweight.php and use the calculator.

larry10s
08-20-2011, 05:09 AM
strings add about 15 grams to static weight
dampener and over grip about 5 gms
srings add about 30 units to sw
balance point moves about 3 points less headlight

TennisCJC
08-21-2011, 06:28 AM
Why don't you just look at the 4d 100 racket specs on TW site. The specs below are from TW Power Zone Comparison page. It is a strung Dun 4D 100. I assume they don't have an overgrip or dampener in the racket but could be wrong. Dampener range from 1.5 g (Sampras O) to about 3 grams for a solid round dampener. Overgrips add about 4-6 grams. Replacement grips also vary in weight with leather usually being the heaviest. Strings vary from 14-18 grams but roughly change balance 3 pts less HL. You also can calculate the balance by placing the head end of the racket on a flat surface and adjusting the racket until it just barely maintains balance. Then measure the distance from tip of head to end of surface. But, then subtract that number from the length to get the distance from the butt to the balance point. By the way, the 4d 100 has a very low SW and very low TW. This racket will play loads better with a bit of weight at 3/9 o'clock and weight in the handle to balance the additional head weight. I would add 6 grams at 3/9 (3 grams each side and 1 gram at 12 o'clock) and counter with 7 grams under the grip to maintain balance. Then, you will be cooking with fire instead of matches.

Length = 27.00
Headsize = 90
Weight = 330.2
Balance = 32.20
Swingweight = 310
Twistweight = 8.93