How do I Weight UP my Federer K factor and change the balance.

Replies to This Discussion

Permalink Reply by Bill Huynh on July 9, 2009 at 12:22pm

Hey there CoachV.
I have done customizing racquets for my customers, not necessarily any pros. Most of them already have theirs weighted when I string them. I would recommend to add weight to the 10 and 2 of the frame, and add equal amounts of weight in the handle of the frame. Not inside through the butt cap, but rather under the grip. This will help with the stability at the head, and the equal balance of weight in the handle will not make it as head heavy. If you have a balance board, toggle with that a little bit as you add more weight to the head or the butt cap until it is the right head pts and the correct weight. Hope this helped.

Bill Huynh

P.S. I spell racquet like this. Don't trust spell checker haha

Permalink Reply by Meags on July 9, 2009 at 12:36pm

Racket Racquet are both correct.

I agree with Bill
I add at 10 & 2 it raises the sweetspot a little, adds stability. Also add the same at the top of the buttcap underneath the grip to keep the same balance and add and remove to get the right balance point for you.
As I use a lighter weighted Head Radical I add 20g at the top of the handle too which takes it to 13oz and makes the racket more headlight similar to your Wilson.

Permalink Reply by Gary Sakuma on October 5, 2009 at 12:32am

for every two grams you place on the head, you place one gram in the buttcap to balance it out.

get a USRSA guy to balance it out for you, they have a machine to test flex plus can balance it out to the like .01 grams

Permalink Reply by Michael Maidens on November 10, 2009 at 1:03am

Hey CoachV
I'm with you. I need extra weight in my racquet. To be more accurate I need more swing weight. I recently had a lecture on all of this with my Level 2..
You probably already know this but maybe other readers dont.. There are 2 types of racquet weight..
Swing Weight and Total Weight.. What does that mean?
Swing weight - is how heavy the racquet feels when held from the handle. The extra weight is felt as you swing it.
Total Weight - is how heavy it is on the scales. It doesnt matter where the weight is distributed - the weight will be the same..
Then you have a balance point.. Which tied into the distribution of the weight in the racquet.
So, for me, I like extra swing weight. I want it to feel heavier in the head. The reason for this is that I like to have long smooth strokes. With a light racquet (swing weight) I feel like I need to muscle the strokes through the point of impact. Therefore I prefer to start the momentum of the racquet and let the swing weight continue the stroke.
This is great for ground strokes and serves - however worse for reflex volleys. With a heavier head the racquet is less 'whippy'. It is also great for playing against heavier hitters because of the total mass and counter punching..

I have weighted up my Head Radical... Actually, I inherited these from a Tour Player and the numbers are
Length: 698 (mm)
Weight: 345 (g)
Balance Point: 316 (distance in mm from handle)
Swing Weight: 349 (g)
DA: 74
G: 3
I am not sure what DA and G mean...

Anyway hope this helps add to the learning :)
Michael

Permalink Reply by CoachV - William Vazquez on November 10, 2009 at 7:31am

I like heavy racquets too, my perception is that the weight whips the ball for me. Nice post. I am learning allot from everyone keep them coming

Michael Maidens said:

Hey CoachV
I'm with you. I need extra weight in my racquet. To be more accurate I need more swing weight. I recently had a lecture on all of this with my Level 2..
You probably already know this but maybe other readers dont.. There are 2 types of racquet weight..
Swing Weight and Total Weight.. What does that mean?
Swing weight - is how heavy the racquet feels when held from the handle. The extra weight is felt as you swing it.
Total Weight - is how heavy it is on the scales. It doesnt matter where the weight is distributed - the weight will be the same..
Then you have a balance point.. Which tied into the distribution of the weight in the racquet.
So, for me, I like extra swing weight. I want it to feel heavier in the head. The reason for this is that I like to have long smooth strokes. With a light racquet (swing weight) I feel like I need to muscle the strokes through the point of impact. Therefore I prefer to start the momentum of the racquet and let the swing weight continue the stroke.
This is great for ground strokes and serves - however worse for reflex volleys. With a heavier head the racquet is less 'whippy'. It is also great for playing against heavier hitters because of the total mass and counter punching..

I have weighted up my Head Radical... Actually, I inherited these from a Tour Player and the numbers are
Length: 698 (mm)
Weight: 345 (g)
Balance Point: 316 (distance in mm from handle)
Swing Weight: 349 (g)
DA: 74
G: 3
I am not sure what DA and G mean...

Anyway hope this helps add to the learning :)
Michael

Permalink Reply by CoachV - William Vazquez on February 17, 2010 at 11:54am

I have an old wooden racquet. its weight is between 12.5 and 13.78, maybe I should weight up my racquet more?

Permalink Reply by Jason Lampione on March 6, 2010 at 7:35pm

Dear Coach-V,

You certainly can balance the racquet according to the specifications of your liking, however, if you do it yourself more likely than not you will probably have a racquet that is not balanced corrrectly. I would suggest having the support of a local U.S.R.S.A., because they have callibration machines that can target the balance weight and distribution through-out your entire racquet by a factor of 0.1 grams. If you wanna take the Macgyver approach, then you can easily measure the lead tape using a measuring utility or a simple ruler will do. Measure within one inch parameter mark, cut, and attatch the lead piece to 12-3-6-9 points on the frame. I've done a study where a player actually put lead tape on the bottom of his grip, then replaced the grip and re-wrapped it. I don't know the out-come of the extra lead, but I can assume it was personal preference. If you need further assistance, please let me know.

Sincerely,

Jason Lampione.

Permalink Reply by CoachV - William Vazquez on March 7, 2010 at 12:18am

Being USRSA certified is not necessary for weighting UP Racquets, A good balance board and understanding of weight placements is all that's necessary, but within manufacturing years I have learned that they constantly change the raquets slightly. N code 6.1 tour and the K factor tour are the same racquets except that the handle is slightly shaped differently and the grommet placements are different by mm. this is part of my balancing problems, I have all my racquets right now around 13.1 Oz I am planning to go up to 13.5 but the grip shapes and grommet placing make it really hard to get it perfect. I need to buy an extra sensitive weight scale and hyper focus on every detail. but I am also working on doing it on a budget. Details are exact same leather grip, over-grip, butt caps, strings all that stuff, generally placing the weights in the same spots and everything, but I dont know everything and I am trying to learn it here. I have place Weights at the 10 & 2 spots & the 7 & 5 spots, only one of the racquets I had to place a weight in the grip because it was the lightest of the group. when I go up sometime this year I will place weight in the handle, BUt where in the Handle and WHY?

Jason Lampione said:

Dear Coach-V,

You certainly can balance the racquet according to the specifications of your liking, however, if you do it yourself more likely than not you will probably have a racquet that is not balanced corrrectly. I would suggest having the support of a local U.S.R.S.A., because they have callibration machines that can target the balance weight and distribution through-out your entire racquet by a factor of 0.1 grams. If you wanna take the Macgyver approach, then you can easily measure the lead tape using a measuring utility or a simple ruler will do. Measure within one inch parameter mark, cut, and attatch the lead piece to 12-3-6-9 points on the frame. I've done a study where a player actually put lead tape on the bottom of his grip, then replaced the grip and re-wrapped it. I don't know the out-come of the extra lead, but I can assume it was personal preference. If you need further assistance, please let me know.

Sincerely,

Jason Lampione.

Permalink Reply by Jason Lampione on March 10, 2010 at 5:59pm

Dear Coach-V,

To better answer your question about whether "Adding lead-tape to your grip," either adds or diminishes your capacity to generate more power or control. This really depends wholly on the person using the racquet. For example, is the person using the racquet strong enough physically to swing a racquet that is 13o.z. in weight, because there is a vast difference between stationary weight and swing weight. The more motion that is imparted on the racquet the more external velocity it needs to generate "racquet head speed" in order to increase and transfer the power (mass) either into or onto the object being targeted. I have included a few reference points that will guide you closer to your goal; I hope this information was educating and insightful.

Here is a link that as an online calculator to measure the lead tape in grams:

http://www.racquettech.com/store/learningcenter/lc_swingweight.html

Here is an article I have researched:

An experiment in adding mass to the tip of a tennis racquet
In a recent discussion on a Tennis Warehouse message board discussion, a poster asked if anyone had analyzed the changes in weight, balance, and swingweight per inch of lead tape added at the tip of a racquet. Also, there was a question of how the racquet has to be oriented in the mount when measuring swingweight. I decided to provide answers to each of these inquiries.

My measuring device is a Prince PTC. I did not calibrate it prior to performing these measurements, because the measurements only have to relate to each other, not the outside world, and I'd just eaten a huge Kobe beef hamburger and had Vinnie Moore's "Time Odyssey" blasting from the iPod Hi-Fi, so calibration was simply too much to ask. Note that the scale of the Prince PTC reads to the half-gram only.

I chose as my test racquet a Prince O3 Tour MS (internal ID #1), which was strung with Wilson Reaction 16. It had a replacement grip but no overgrip, a rubber grip band at the top of the replacement grip, and some built-up material in the handle between the end of the butt cap and 6.5 inches up. The racquet as tested was 26-15/16 inches in length. The other measurements appear in the table below.

I added ¼-inch lead tape in paired strips four inches long at the inside of the hoop at the tip (AKA the 12 o'clock position). Normally, I would not add lead to this racquet in this position because of the O Ports, and if I did, I would contour the tape into the O Ports. For this test, the tape lay more or less along the inner contour of the frame at this point. I use a lengthy strip of lead tape that I had just recycled from one of my Wilson Hyper Pro Staff ROKs, instead of using new tape that in all eventuality will be discarded shortly after this experiment.

I took the weight and balance measurements with the racquet in the same orientation each time. I took the swingweight measurements four times at each racquet weight, once on each of the four main "bevels" of the frame:

1.Up signifying the "P" on the butt cap is right-side up;
2.Right signifying that the "P" on the butt cap is lying down on its right side (a proper way to mount a frame);
3.Down signifying that the "P" on the butt cap is up-side down; and
4.Left signifying that the "P" on the butt cap is lying on its left side (a proper way to mount a frame).
During this experiment, the temperature was 75°F and the Relative Humidity was 44% (that is, a dewpoint of 40°F).

The center of the first strip of lead was 26.5 inches from the butt cap. However, the ends of this four-inch section were only 26 inches from the butt cap. When simply adding lead tape to a racquet to see what how it feels, this is not a problem. However, when adding lead tape in an attempt to duplicate the weight, balance, and/or swingweight of another racquet, typically the calculations call for adding X amount of lead tape at position Y on the frame. Due to the curvature of the frame, however, the exact centerpoint can be difficult to determine with accuracy. Because of the thickness of the strips of lead tape, the center of the eighth and final layer of lead tape was 26-7/16 inches from the butt cap, and the ends were 25-7/8 inches from the butt cap. This would further compound accurate calculation of during racquet matching.

As a check against heat-related error within the Prince PTC, after the final "weighted up" measurements I stripped the racquet back to its starting configuration and remeasured, achieving the same measurements as I did in establishing the baseline measurements.

Here, then, are the results, with the weight in grams, the balance in centimeters, and the swingweight in kg•cm² as it must be:

Measured changes Configuration Weight Balance Up Right Down Left
Baseline 353.5 30.3 341 324 342 324
+8 inches 356.5 30.5 347 330 347 332
+16 inches 359 30.7 353 337 353 338
+24 inches 361 30.9 359 343 360 344
+32 inches 363 31.1 366 349 366 350
+40 inches 365 31.3 372 356 372 356
+48 inches 367 31.5 378 362 378 362
+56 inches 368.5 31.7 384 368 384 368
+64 inches 371 31.85 387 374 385 374
Baseline check 353.5 30.3 341 324 342 324

Not surprisingly, the edge-on swingweights (labelled "Up" and "Down" in the first table above) are way off from the properly-measured swingweights. I suppose that, to be rigorous, I should re-run this test with a racquet that does not have huge holes in the frame, to see what role aerodynamics play. I have no explanation or theory about the slight scatter in the Up/Down and Right/Left data, but I've seen it often enough that I expected it. You can only imagine what happens when you attempt to compare measurements of this sort taken from two different uncalibrated machines operated under different conditions, let alone if one of the operators doesn't know the correct way to mount the racquet in the first place.

I took these figures and plugged them into a spreadsheet I use when matching and modifying racquets.

Because the measured figures did not agree with well-established formula for calculating the changes in racquet characteristics as a known mass is added to a known position on the frame, I took the two stacked strips of lead tape and weighed them on a beam balance. The lead tape that added 17.5 grams according to the Prince PTC actually weighed 14.744 grams, far short of the advertised one-quarter gram per inch. (This is just one reason why, when working on racquets where accuracy is important, I use 3M Model #420 Professional Lead Tape from Grand Slam Stringers instead of the bargain bulk-pack lead tape.)

I took the 14.744-gram figure, added it to the starting mass of the racquet, and ran the numbers again. This time, the agreement was much better between the measured results and the calculated results, as seen in the table below. It appears that I should have taken a few moments to calibrate the PTC before embarking on this adventure, and checked the calibration throughout the experiment.

Calculated changes Configuration Weight Balance Swgwt
Baseline 353.24 30.3 324
+1.843 355.08 30.49 330
+3.686 356.93 30.68 336
+5.529 358.77 30.87 342
+7.372 360.61 31.05 348
+9.215 362.46 31.24 354
+11.058 364.30 31.42 360
+12.901 366.14 31.60 366
+14.744 367.98 31.78 372

I believe I've established that the formulas used for racquet matching and modification are correct — at least to the limits of my ability to cut lead tape accurately and apply it at the appropriate position on the frame. The problems seemed to arise from measuring the effects of the modifications once made. It appears that we need measuring equipment that is more accurate and with higher resolution than that currently available to the average racquet technician.

This is not a knock on the Prince PTC, as it is state of the art for professional equipment of this type. It some ways, it is better than the "industry standard" machine against which it competes.

For example, the next day I turned the PTC on again and re-ran the baseline and +64 tests. This time, I got 353 grams for the baseline mass, with a swingweight of 324 kg•cm². The two strips of lead tape showed as weighing 14.5 grams (which they would with a resolution of .5 grams), and the total mass of the racquet was 368.5 grams. Thus, the PTC was only one-half gram off at this point from the separate measurements, assuming that the measurement of 353 grams could have been as high as 353.24 grams.

After adding the lead strips back onto the racquet, the swingweight again measured 374 kg•cm². Given that the calibration method gets you within ±1, the measured swingweight is within the machine tolerance for theoretical swingweight. It's just unfortunate that for those attempting to achieve perfection, these seemingly minute differences (including the differences between the advertised weight-per-inch of lead tape and the actual value*) can create major difficulties in measuring and applying lead tape, and checking the results of ones efforts.

Probably what we need is for racquet technicians around the world to get more involved with racquet matching and modification. The more demand there is for accurate measuring equipment, the better chance we'll have of actually seeing that equipment on the market.

Sincerely,

Jason Lampione.

Permalink Reply by pieter de rooij on November 20, 2013 at 7:22am

I would like custom made. Excact include my grip size Does anyone know an address who can do that?!?!

 

Sincerly,

 

Pieter de Rooij (the Netherlands)