Sampras head 2 thick layer of lead right above the grip under the replacement grip too.. that's how he counter balance the heavy lead strip at 3 & 9.
i've heard that a couple times now? how do you know that to the case? I've made the following calculations to those familiar with a bit of leverage physics and/or racket matching, along with some specs courtesy of greg raven
http://www.hdtennis.com/grs/pro_racquet_specs/sampras_wilson.html
standard racket lenth = 69 cm
standard kps88 balance pt. = 32.4-32.6 cm or so
sampras balance pt. = 32.1 or so
(for simplicity, assume i want to keep balance at 32.6ish)
standard kps88 weight = 363 g
sampras weight = 384
amount of weight i have to play with= 21 g
center of mass of any lead tape placed at 3 and 9 is about 17 cm down from the top of the frame as i measured this morning, which means the "lever arm" of the 3/9 lead has length (69-32.6)-17 = 19.4 cm.
length from bottom of handle to top of pallet (where i'd put lead if under the grip, any lower and it'll impede my grip of the racket) ~14cm which gives a lever arm (from 32.6) of about 32.6-14 = 18.6cm
lever arm if i put it in bottom of handle ~ 32.6cm
two situations: one where i put lead under pallet at top of handle, one where i put it inside handle at bottom of grip.
situation one: unknowns: m1 = mass in handle, m2 = mass at 3/9
equations: m1 + m2 = 21 g
m1*18.6 = m2 * 19.4 (torque balance equation)
solution: m1 = 10.7 g
m2 = 10.28 g (~ 10.28 inches of lead tape overall, there'll be 4 strips in total, each strip has about .25 grams per inch, = 1 gram per inch = about 10.28 inches, probably accomplished by a 5" strip on top of a 5.5" strip, roughly)
situation two: unknowns m1 = mass in handle, m2 = mass at 3/9
equations: m1 + m2 = 21 g
m1* 32.6 = m2 * 19.4
solution:
m1 = 7.8 g
m2 = 13.2 g (by the above, this would be something like 13 inches of lead tape, likely accomplished by 6 inches + 5 inches + 2 inches maybe?)
in my mind situation 2 seems more likely simply because i guess i'm used to seeing a big honking wallop of tape on pistol's racket at 3 and 9. i remember looking at greg raven's pictures of the sampras racket (look at above link), and seeing 3 strips, one that was like 6.5 inches, 6 inches, and something like 5 inches on top of each other. that's a butt ton of lead. even thought the 85 is considerably lighter, according to tw, it's not THAT much more head light that pistol would go from having 17.5 ish grams of lead at the head to having only about 10. going from 17.5 to 13 seems more believable. on the other hand, that ps85 that's on greg raven's sight is a st. vincent, and i don't know how different the stock spec is.
so based on my analysis i'm lead to believe that situation 2 is more likely, and that pistol has the weight in the bottom of his handle. what do you guys think? (besides thinking that i have too much time on my hands)