Exact Sampras Setup-new KPS 88

chiru

Professional
hi, does anyone have relatively exact specs (and a reason to believe them :p ) on how pete customizes his new kps 88? I had exact measurements on how much leadtape to use on the ps 85 from back in the day, but the 88 is more headheavy to begin with. I.e. if i throw the exact same amount of lead on the 88 as I have on the 85, it'll be much more headheavy than the 85. maybe that is how sampras has it? maybe sampras adjusted everything so that it has the same specs as the 85? anyone have any definitive answers on this? also, does anyone have anything definitive re: the handle? did sampras counterweight in the handle? or only the lead tape on the head? both new and old information will be useful to me, but the newer the better :p

before anybody jumps on me saying "use whatever build fits YOU best" or that stuff...thanks...i uh...never thought to try that. maybe next time. for now, please just humor me. I built my 85 that way in the past and it felt pretty good. if pete changed the stock weight, balance, or anything else after switching to the kps88, I'm curious why.
 

Azzurri

Legend
one poster (is it greg raven?) had the actual smapras racquet. try to send him an email..he may be able to help. I agree that the set -up may be different in the KPS88 because of the weight and balance.
 

VGP

Legend
Out of curiosity, did you swap out the leather on your PS85 to a synthetic? Are you going to do the same for the kPS88?

I only ask because Sampras uses a synthetic grip these days (he did post 2000 too)......do you use Tournagrip and a cable grommet? Power pads?

I'm curious as to how far you're taking the Sampras racket emulation.....
 
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.
 

chiru

Professional
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)
 
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chiru

Professional
Out of curiosity, did you swap out the leather on your PS85 to a synthetic? Are you going to do the same for the kPS88?

I only ask because Sampras uses a synthetic grip these days (he did post 2000 too)......do you use Tournagrip and a cable grommet? Power pads?

I'm curious as to how far you're taking the Sampras racket emulation.....

i'm using a leather, cuz i like it better, and yes i do use tourna grip. although i'm not sure what a cable grommet is. i don't use powerpads because i don't do my own stringing.

the reason why i'm trying the emulation is because, as i mentioned earlier, the first time i started emulating the sampras racket (by putting a big honking couple strips, 6.5" and 6" to be exact) at 3 and 9 i felt the solidness and stability of the racket had VASTLY improved. i didn't put any in the handle, because i guess i just never did. i'm curious to see if it makes any difference.
 

VGP

Legend
I find it a bit funny that some people look at the amount of lead placed on a Sampras frame (like the one Greg Raven has) and think that's the amount that HAS to be put at 3 and 9. I'm not implying that you, chiru, feel that way. GR didn't take apart the handle as not to decrease it's value, but I'm sure there's lead for counterbalancing.

If you watch the '95 Australian Open QF between Sampras and Courier, the length of the visible lead at 3 and 9 is different depending on the frame he's using. Nate Ferguson says that he tries to recreate Sampras' favorite frames.

As we know, the SV PS85 is made to the tolerance window spec range.....so......it depends on the rackets you're dealing with. Some will require more lead, some less. The kPS88 is no exception.

I'd measure your PS85 and try and recreated the static weight and balance that you've been enjoying (sounds like you've already matched to GR's Sampras frame). Just apply it to your kPS88s in a manner that you describe. Either way should work, but perhaps Sampras goes for a "look" of the long strips and adding more - if needed - depends on the layering. Sounds like you're leaning this way too.

The "stock" TW weight is an average of some of their stock. It might not be what you have or get. Your 21 gram window just may not apply to each of your kPS88s.
 

VGP

Legend
chiru - in addition, you seem the "meticulous" type so keep in mind you'll have to adjust for your preferred string's weight......

.....and a cable grommet is what Sampras uses as a vibration dampener.
 

chiru

Professional
chiru - in addition, you seem the "meticulous" type so keep in mind you'll have to adjust for your preferred string's weight......

.....and a cable grommet is what Sampras uses as a vibration dampener.

that's a good point you bring up regarding the preferred string's weight. unfortunately, i change up my strings quite a bit so that's why I'd prefer to match an unstrung racket with another unstrung, and let the weight of the string be a variable I mentally just group as a part of the string's characteristic which i'll either hold against it or not.

the issue for me then is that i intend to do matching work with an unstrung frame to specs that are on greg raven's site which are a strung frame. (all my ps85's are strung right now...2 of em with gut, another with a good multi...heh...cutting it out is not an option ;) ). greg mentioned that it's just a standard nylon ( i guess syn gut is what he means?) that was installed by the usrsa. how do i find out how much a string job of nylon should weigh? the issue is, since it's a ps85, it's hard to say exactly how much string is on the racket (because of the headsize) and you of course can't simply say that it's the weight of one set of string. that feels like a conundrum to me...
 
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