Make my 93p more...K90-like?

Hey friends! Impulse bought a 93p (18x20) after a nice little demo sesh last month and still trying to get things fully dialed in with it. It's a great racquet as-is, don't get me wrong, but I'm really trying to make it sing.

For context, I'm coming from a K90 and I absolutely love the weight, balance, and swingweight of that racquet. I love it's stability and solid plow-through on impact.

So, that being said, can someone who's more knowledgable than me when it comes to spec matching different racquets guide me on lead amount and placement to make my 93p more...K90-like?

Also, love you guys, but please no "why didn't you buy an RF97," "lol just buy another K90," or "have you tried the new Prestige Mid?" replies. What's done has been done. :laughing:
 

lelopez

Semi-Pro
To get the 93p's I got closer to my k90s I added lead both at 12 o'clock and handle. If I remember correctly I ended up with 355g static and 348sw with about 31.7cm balance. Think it was 6-7g in the hoop and another handful of grams in the handle. Still, I was never really able to re-create the k90 magic and weight of shot on the ball, which is why I punted and went back to my k90s.

It is a nice stick and does swing easier than the k's, so if that's what you're after, just play with a little lead and I'm sure you'll be satisfied. I don't think it needs it at 3 and 9, just 12.
 
To get the 93p's I got closer to my k90s I added lead both at 12 o'clock and handle. If I remember correctly I ended up with 355g static and 348sw with about 31.7cm balance. Think it was 6-7g in the hoop and another handful of grams in the handle. Still, I was never really able to re-create the k90 magic and weight of shot on the ball, which is why I punted and went back to my k90s.

It is a nice stick and does swing easier than the k's, so if that's what you're after, just play with a little lead and I'm sure you'll be satisfied. I don't think it needs it at 3 and 9, just 12.
Interesting, 12 o'clock huh? I did experiment with lead at 10 & 2 for one session and took it off immediately after...just didn't feel like the right balance. Dumb question maybe, how are you adding lead to the handle? Inside? Idk why I'm terrified of tinkering with anything to do with the inside of the handle.
 

Irvin

Talk Tennis Guru
93P = 346 g, 31.5 cm, 329 SW
[K]90 = 354 g, 31.0 cm, 336 SW

You want to lower the balance 0.5 cm by adding 8 g to the 93P. You can do that by adding 8 g at 9.375 cm from the butt. Or you could divide the 8 g into 2 4 g amounts and place 4 g equally above and below the 9.375 points. If you add 4 g at 1.375 and 17.375 cm you can add BUT you want to increase SW by 7 points while maintaining the weight and balance, That is impossible! You’re going to have to come up with some compromise for your specs.
 
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golden chicken

Hall of Fame
Personally I like the 2/3 point solutions better (they are roughly the same) because they distribute the lead more evenly about the racket.

I find if I add 2g or more to one spot on the head that I can feel the lead the same way I can tell where a hammer will hit the nail without looking at the hammer.

But some people are not sensitive like that. You have to experiment.

As for adding weight on the handle, I would tightly wrap some scotch tape around the bare base grip sticky side out and stick the lead to it in two strips lengthwise, then wrap my overgrip over it. The tape and overgrip will keep it in place.

If you like the lead on the handle (I find it makes no difference to me) then you could wrap another piece of scotch tape sticky side in around the sticky side out tape so that it doesn't stick to the inside of your overgrip.
 

Irvin

Talk Tennis Guru
93P = 346 g, 31.5 cm, 329 SW
[K]90 = 354 g, 31.0 cm, 336 SW

You want to lower the balance 0.5 cm by adding 8 g to the 93P. You can do that by adding 8 g at 9.375 cm from the butt. Or you could divide you 8 g into 2 4 g amounts and place 4 g equally above and below the 9.375 points. If you add 4 g at 1.375 and 17.375 cm you can add BUT you want to increase SW by 7 points while maintaining the weight and balance, That is impossible! You’re going to have to come up with some compromise for your specs.
@goldenhawktennis also it is not only possible but highly probably the specs of your old and new racket are not the same as the TW specs. Do it right have them measured.

For a compromise I would add the least amount of weight at 12 o’clock to increase the SW by 7 points - 2 g. Then add the other 6 g in the butt. Your weight and SW will match but your balance will be off.
 

Irvin

Talk Tennis Guru
Personally I like the 2/3 point solutions better (they are roughly the same) because they distribute the lead more evenly about the racket.
I like your way of thinking. I prefer to use torque / weight to identify how to match weight and balance by placing all the weight at one location and see how that changes the SW. rarely do I ever get exactly what I want. You can then divide the weight evenly up and down at equal distances to increase SW but maintain weight and balance. Splitting either the top of bottom weight again increases SW more and still maintain weight and balance.

But rather than using an online calculations I prefer to do my own so I can see exactly where I’m going rather than using compromising built into the calculator.
 
93P = 346 g, 31.5 cm, 329 SW
[K]90 = 354 g, 31.0 cm, 336 SW

You want to lower the balance 0.5 cm by adding 8 g to the 93P. You can do that by adding 8 g at 9.375 cm from the butt. Or you could divide you 8 g into 2 4 g amounts and place 4 g equally above and below the 9.375 points. If you add 4 g at 1.375 and 17.375 cm you can add BUT you want to increase SW by 7 points while maintaining the weight and balance, That is impossible! You’re going to have to come up with some compromise for your specs.
Got it. Curious, how did you arrive at the 9.375 cm number? In my screenshot above, it seemed the TW calculator recommended the 8g at 15 in. from the butt? I don't have a tape measure on me at the moment (currently in an airbnb), but 9.375 cm from the butt seems significantly lower and might land somewhere on the upper handle? Also, can you clarify the 1.375 and 17.375 cm placements you referenced?
 
Personally I like the 2/3 point solutions better (they are roughly the same) because they distribute the lead more evenly about the racket.

I find if I add 2g or more to one spot on the head that I can feel the lead the same way I can tell where a hammer will hit the nail without looking at the hammer.

But some people are not sensitive like that. You have to experiment.

As for adding weight on the handle, I would tightly wrap some scotch tape around the bare base grip sticky side out and stick the lead to it in two strips lengthwise, then wrap my overgrip over it. The tape and overgrip will keep it in place.

If you like the lead on the handle (I find it makes no difference to me) then you could wrap another piece of scotch tape sticky side in around the sticky side out tape so that it doesn't stick to the inside of your overgrip.
Interesting, makes sense. That's part of the reason I immediately took off the lead at 10 & 2; it was too much and I could feel it too noticeably. But given those diagrams in options 2 & 3, seems incredibly difficult to pull off the exact placement points and fractions of a gram of lead? I liked option 1 just for the simplicity of placement and round number.
 
@goldenhawktennis also it is not only possible but highly probably the specs of your old and new racket are not the same as the TW specs. Do it right have them measured.

For a compromise I would add the least amount of weight at 12 o’clock to increase the SW by 7 points - 2 g. Then add the other 6 g in the butt. Your weight and SW will match but your balance will be off.
Sorry last thing, can you also share your method for adding weight to the butt? This has always terrified me. I'd hate to do irreparable harm to my racquet.
 

aaron_h27

Professional
Interesting, makes sense. That's part of the reason I immediately took off the lead at 10 & 2; it was too much and I could feel it too noticeably. But given those diagrams in options 2 & 3, seems incredibly difficult to pull off the exact placement points and fractions of a gram of lead? I liked option 1 just for the simplicity of placement and round number.
The 93P already has a much higher twistweight than the K90 so i would not put any lead on the sides of the frame. Lead at 12, 6 or the handle/throat should be ok
 

Irvin

Talk Tennis Guru
Sorry last thing, can you also share your method for adding weight to the butt? This has always terrified me. I'd hate to do irreparable harm to my racquet.
It will depend on the racket and the point where I want to add lead. More often than not I can add lead under the OG / grip just above the butt cap and o at the top of the grip where the pallet tapers down. If the point where I needed to add weight was 9.375 cm I would split the weight in half and add half just above the butt cap and the rest at the top of the grip. If you want to widen on make the grip taller you could put the weight down the top or side bevels.
 

Irvin

Talk Tennis Guru
Got it. Curious, how did you arrive at the 9.375 cm number?
Sorry missed that question. Fir I multiply the weight and balance of each racket (torque.) in your case [K]90 = 10,974 and 93P = 10899 gcm of torque. Divide the difference in torque (if the lighter racket has the least torque) by the difference in weight 8 g. 75/8 = 9.375.

if the lighter racket has the greater torque you need to add mass to the heavy racket to increase torque.

Know where and how much weight to add gives you the increase in SW if there is any. The difference in cm from the SW axis, 10 cm, times the mass in kg gives you the SW increase. (10-9.375)*0.008 = 0.00323 is nothing. But if you separate the weight SW increases. Remember you wanted a 75 gcm increase in torque, so adding 1 g at 68 cm gives you (68-10 =58) 58*58*.001 = 3.364 increase in SW. now your SW is 329+3.364 = 332.364 just under the 336 you wanted. But you have 7 g mass left to add and you want 75-68 = 7 gcm more torque. Just add 7 g at 1 cm.

Result is your 93P will be 354 g, 31 cm, and 332.4 SW
 

Irvin

Talk Tennis Guru
In my screenshot above, it seemed the TW calculator recommended the 8g at 15 in.
That’s what I don’t like about the Calculator. The calculator in this instance gives you almost a 336 SW but adding all the mass above the balance point gives you a higher balance point. I would rather be 2.6 point off in SW and have my weight and balance where I want it that have the SW and weight on and the balance off. You could also get into MGR/I and get it where you want it but that gets more complicated.
 

golden chicken

Hall of Fame
I wouldn't sweat the exact placement or tenth of a gram here or there. Just try something and swing the racket around a little back to back with the other one. Stop when you can't tell a huge difference.
 
Sorry missed that question. Fir I multiply the weight and balance of each racket (torque.) in your case [K]90 = 10,974 and 93P = 10899 gcm of torque. Divide the difference in torque (if the lighter racket has the least torque) by the difference in weight 8 g. 75/8 = 9.375.

if the lighter racket has the greater torque you need to add mass to the heavy racket to increase torque.

Know where and how much weight to add gives you the increase in SW if there is any. The difference in cm from the SW axis, 10 cm, times the mass in kg gives you the SW increase. (10-9.375)*0.008 = 0.00323 is nothing. But if you separate the weight SW increases. Remember you wanted a 75 gcm increase in torque, so adding 1 g at 68 cm gives you (68-10 =58) 58*58*.001 = 3.364 increase in SW. now your SW is 329+3.364 = 332.364 just under the 336 you wanted. But you have 7 g mass left to add and you want 75-68 = 7 gcm more torque. Just add 7 g at 1 cm.

Result is your 93P will be 354 g, 31 cm, and 332.4 SW
That’s what I don’t like about the Calculator. The calculator in this instance gives you almost a 336 SW but adding all the mass above the balance point gives you a higher balance point. I would rather be 2.6 point off in SW and have my weight and balance where I want it that have the SW and weight on and the balance off. You could also get into MGR/I and get it where you want it but that gets more complicated.
Incredible breakdown. Thank you!
 
I wouldn't sweat the exact placement or tenth of a gram here or there. Just try something and swing the racket around a little back to back with the other one. Stop when you can't tell a huge difference.
Fair enough. I'll get to experimenting here soon. If Colorado could just stop snowing this process would be a lot more seamless :-D
 
Circling back on this thread because @Irvin and everyone who chimed in deserve my kudos! Added 8g of lead to my 93p split 4g above the 9.375 cm point and 4g below (essentially near the butt and top of handle), and boy was the difference in feel almost immediate. Shadow swings in the living room between the 93p and K90 felt much more similar and the transition fairly seamless. Took it out for a hit over the weekend and it felt like I unlocked another level with the phantom that I hadn't previously. My 1hbh felt more solid with greater plow-through and the overall weight and stability just felt...right, especially in trying to make it more "K90-like."

So all that to say, thanks everyone! We might need a few more hits and some additional tinkering, but y'all have guided me in the right direction so far. Cheers!
 

Irvin

Talk Tennis Guru
Shadow swings in the living room between the 93p and K90 felt much more similar and the transition fairly seamless...
So all that to say, thanks everyone! We might need a few more hits and some additional tinkering
Gon't let your significant other see you doing shadow swings in the living room if there are lamps around. LOL

If you like what you have but want to bump up the SW just a little to experiment here is some tips to start with. You can easily match weight and balance by matching torque like when you add 8 g at 9.375. if you want to maintain balance and weight split the weight into 2 equal parts and evenly distribute it above and below the original point, like you did at 4 g at butt and top of grip. Want to keep going? Split that top weight again. If you put 4 g at 1 cm and 17.75 you can split the 4 g weight at 17.75 again. Put 2 g at 1 cm and and 2 g at 34.5. That will increase the SW / plow another 1.1 points. Now you have more weight just about in the center of the racket and you can do it again.
 
Gon't let your significant other see you doing shadow swings in the living room if there are lamps around. LOL

If you like what you have but want to bump up the SW just a little to experiment here is some tips to start with. You can easily match weight and balance by matching torque like when you add 8 g at 9.375. if you want to maintain balance and weight split the weight into 2 equal parts and evenly distribute it above and below the original point, like you did at 4 g at butt and top of grip. Want to keep going? Split that top weight again. If you put 4 g at 1 cm and 17.75 you can split the 4 g weight at 17.75 again. Put 2 g at 1 cm and and 2 g at 34.5. That will increase the SW / plow another 1.1 points. Now you have more weight just about in the center of the racket and you can do it again.
Lol, we're in an airbnb so she just rolls her eyes and hopes I don't knock something off the shelf. I'm of course more worried about any scratches/paint chips to that beautiful midnight purple paint ;)

And interesting, that makes sense as well! I'll give it a few more sessions and see if it feels like there's still room for improvement. Thanks again!
 

Anton

Legend
oh wow, did not know this tool existed...super cool. did I do this right? does that feel accurate? if so, the first option seems far and away the best/easiest solution here

Lead on V throat is key to getting 93p rock solid, so definitely more like 1st option
 

Irvin

Talk Tennis Guru
Lead on V throat is key to getting 93p rock solid, so definitely more like 1st option
You are making a lot of assumptions. IMO none of those results will be as close as I would like. And I would like to know the exact results so I can decide what I want. The user may love one or more of the solutions but they all give differenct results.
 

Anton

Legend
You are making a lot of assumptions. IMO none of those results will be as close as I would like. And I would like to know the exact results so I can decide what I want. The user may love one or more of the solutions but they all give differenct results.
Lol what? I've used both K90 and 93P and I'm saying the 93P needs weight in the midsection to match k90's stability. It's a specific 93P starting point when adding weight because it's a bit unstable in the lower stringbed.
 
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Irvin

Talk Tennis Guru
Lol what? I've used both K90 and 93P and I'm saying the 93P needs weight in the midsection to match k90's stability. It's a specific 93P starting point when adding weight because it's a bit unstable in the lower stringbed.
All three of the solutions result in about the same balance and weight but the three solutions are different. I you want to increase the SW you should distribute the mass more. Distributing the mass more increases the RW by polarizing the frame. The greater the RW the greater the SW

SW = RW + mr^2

If mass and radius are the same any increase in RW is directly proportional to an increase SW.
 

WYK

Hall of Fame
I'd just slap some lead at 12 o:clock and go play. It adds SW and will make the hoop 'feel' slightly stiffer. Adjust as you see fit.
 
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