Pro Swing Weight?

[travlerajm]

Originally Posted by Pioneer

Hmmm. I used Federer's low SW specs (338 kgxcm^2) but if we assume his target SW is about 350, I believe the number will come closer to 21.1

I calculated Safin's MgR/I with Greg Raven's specs and it came out 18.5 but I believe if we use the unstrung specs by Thomas Martinez where the static weight is also about 353g but the SW is about 355-360 I'll get different results.

PS: using Safin's unstrung specs and converting them to strung I get around 20.11

You might want to recheck your calculations - the Safin racquet in Greg Raven's collection (347 SW, 32cm, 353g) comes in at MgR/I = 20.6 (which I believe to be optimum for someone 6'4" tall with his grip).

And again, I believe ART ART's posts of Fed's specs from two separate tournaments (353 for Wimbledon '09 and 354 for another - I don't recall which). I can't recall the balance he posted, but I do remember that his MgR/I came out in the 20.9 range.

[Pioneer]

Originally Posted by travlerajm

You might want to recheck your calculations - the Safin racquet in Greg Raven's collection (347 SW, 32cm, 353g) comes in at MgR/I = 20.6 (which I believe to be optimum for someone 6'4" tall with his grip).

And again, I believe ART ART's posts of Fed's specs from two separate tournaments (353 for Wimbledon '09 and 354 for another - I don't recall which).

Sh*t, when calculating for Safin I added 100M instead of subtracting it. Sorry

[Chapter 24]

I took my back-up racquet off the shelf yesterday and using the MgR/I formula and the Customization and Reverse Engineering Tool from The tennis Warehouse University, I leaded up the unit so as to achieve a value of MgR/I = 20.997

I was able to do this while achieving something in the Swing Weight and Total Weight ranges that I had already determined as acceptable for me.

I was really pleased (and pleasantly surprised) with the result.

Before I'm convinced, I want to do more investigation on my main racquet which, to my disappointment is much less ideal for leading up because the SW and Total Weights are both high on it in the un-modified state. The only way for me to get up around 20.85 to 20.90ish from what I can figure out will be to add all my weight in the throat area. That is, to approach this desired MgR/I value while not exceeding my comfort SW range.

If this second modification/playing test is also successful I will report back.

[PED]

Originally Posted by Chapter 24

Before I'm convinced, I want to do more investigation on my main racquet which, to my disappointment is much less ideal for leading up because the SW and Total Weights are both high on it in the un-modified state.

Just curious, but what is your racquet? I was guessing that maybe it was a Wilson as there are not that many sticks with both a high SW and a high static as well. My son uses the blx 95 16X18 and its hefty stats are similar to what you mentioned above. For me, I don't like to go above 350g static.

I'll be curious as to how the throat weight works. In my experience, it changed the feel a bit and I never cared for that.

There don't seem to be that many pro sticks with weight in the throat that I've seen, it generally seems to be on the hoop or the handle. Def let us know how it goes.

[Power Player]

Originally Posted by Pioneer

You can do a lot of hard hitting with the same SW in the top 100.

I agree. I actually worded it the way I did because it seems that some rec players on here like to try and use the same high 355+ Sweights as some pros. In my experience, unless you play 4 hours or so a day with that SW (like a pro would), it is not worth going that high. My ideal SW is 335 because I only play 2-5 times a week. I came down from 350, which I simply did not need.

Just my experience, but you are correct, you can hit a very heavy ball with a SW in the 330-350s, and still handle whatever comes back at you...even at a top 100 level.

[Chapter 24]

Originally Posted by PED

Just curious, but what is your racquet? I was guessing that maybe it was a Wilson as there are not that many sticks with both a high SW and a high static as well. My son uses the blx 95 16X18 and its hefty stats are similar to what you mentioned above. For me, I don't like to go above 350g static.

I'll be curious as to how the throat weight works. In my experience, it changed the feel a bit and I never cared for that.

There don't seem to be that many pro sticks with weight in the throat that I've seen, it generally seems to be on the hoop or the handle. Def let us know how it goes.

The racquet that seems problematic where I figure I need to lead up the throat to get near 21.0 is the Bab APDGT

Of course if I was willing to go into SW's above 340 the number of options for where and how much lead open up.

I agree about the throat being unusual...part of the reason for the test of the magic 21.0 value. Jamming a bunch of lead onto the throat of the racquet flies in the face of most of what I have read on this board about the how's and why's and do's and don't of racquet customizing.

[travlerajm]

Originally Posted by Chapter 24

The racquet that seems problematic where I figure I need to lead up the throat to get near 21.0 is the Bab APDGT

Of course if I was willing to go into SW's above 340 the number of options for where and how much lead open up.

I agree about the throat being unusual...part of the reason for the test of the magic 21.0 value. Jamming a bunch of lead onto the throat of the racquet flies in the face of most of what I have read on this board about the how's and why's and do's and don't of racquet customizing.

Some rules of thumb:

Adding lead to throat area will tend to increase the dynamic stiffness of the frame. At 7", it will only stiffen the frame a little. At 8.5", a bit more. And at 9+", it start to max out the stiffness of your frame if you need to add a substantial amount of lead.

Increasing stiffness has pluses and minuses. It will gererally reduce the spin potential, but increase the power and directional accuracy.

However, the location of lead that you add to the hoop to increase SW will determine the location of the counterweight needed to reach the same mass and balance.

That is, if you add lead at 12, you will likely need to counter somewhere in the throat with several times that amount to restore the same MgR/I value. But if you add weight at 3 and 9, the counterweight will be less mass, and it will be needed to be placed much lower in the handle where it won't affect the stiffness at all. I like to use this effect to "tune" the dynamic stiffness of my frame. If it feels too stiff, I drop the hoop mass location a little lower - I usually start at 10 and 2.

Also, I think you'll find that your SW and static wt tolerances goes up a lot if you use the MgR/I rule to tune your frame. And if you have a 2hb, I recommend using mg(R - 10)/SW = 22.6 to tune it also (same formula, different pivot axis). Both the forehand constrant (MgR/I = 21.0) and the 2hb constraint can be met simultaneously for any SW. Example: 365 SW, 32cm, 13.5oz.

Lastly, I always find that fine tuning is a good idea to find just the right balance (Your magic value for your swing may not be exactly 21.0). To do this, I recommend having a few grams of your counterweight wrapped in a way that you can adjust its location quickly to tune your balance against the wall (or against a patient hitting partner).

[Chapter 24]

Originally Posted by travlerajm

Some rules of thumb:

Adding lead to throat area will tend to increase the dynamic stiffness of the frame. At 7", it will only stiffen the frame a little. At 8.5", a bit more. And at 9+", it start to max out the stiffness of your frame if you need to add a substantial amount of lead.

Increasing stiffness has pluses and minuses. It will gererally reduce the spin potential, but increase the power and directional accuracy.

However, the location of lead that you add to the hoop to increase SW will determine the location of the counterweight needed to reach the same mass and balance.

That is, if you add lead at 12, you will likely need to counter somewhere in the throat with several times that amount to restore the same MgR/I value. But if you add weight at 3 and 9, the counterweight will be less mass, and it will be needed to be placed much lower in the handle where it won't affect the stiffness at all. I like to use this effect to "tune" the dynamic stiffness of my frame. If it feels too stiff, I drop the hoop mass location a little lower - I usually start at 10 and 2.

Also, I think you'll find that your SW and static wt tolerances goes up a lot if you use the MgR/I rule to tune your frame. And if you have a 2hb, I recommend using mg(R - 10)/SW = 22.6 to tune it also (same formula, different pivot axis). Both the forehand constrant (MgR/I = 21.0) and the 2hb constraint can be met simultaneously for any SW. Example: 365 SW, 32cm, 13.5oz.

Lastly, I always find that fine tuning is a good idea to find just the right balance (Your magic value for your swing may not be exactly 21.0). To do this, I recommend having a few grams of your counterweight wrapped in a way that you can adjust its location quickly to tune your balance against the wall (or against a patient hitting partner).

Thanks for the additional tips/ideas ! I still don't think one can go to the hoop on this racquet, the APDGT even at the 3 and 9 positions unless I lower my MgR/I target to closer to the midish 20 values or drastically increase my SW tolerance. As I wrote above, I had great results with my other racquet at 20.97..so i have no reason (yet) to want to move below this.

I experience/experienced some pain in my wrist for serving and overheads only (which hasn't completely gone away about a month later) when I was going SW = 350-355 so for now I'm trying to stay SW = 325-340. The APDGT is SW=331 off the shelf so it creates some challenges.

[Chapter 24]

Maybe for travlerajm who has an awesome amount of tennis knowledge ! (Thanks again for your posts if I have failed to thank you sufficiently up to this point):

I know that you there is a good chance you aren't medically qualified to provide an answer to this question (then again, I could be wrong about that too !!) but just from a tennis/physics point of view, would my wrist problem when serving/overheading that I referred to above be caused/aggravated by total weight or swingweight or perhaps both.

If this helps it hurts the area in the joint specifically on top of my wrist when I push on the front of my finger tips and try to bend my hand backwards towards the top of my forearm. When I serve/overhead I feel this exact same strain.

[PED]

Originally Posted by Chapter 24

The racquet that seems problematic where I figure I need to lead up the throat to get near 21.0 is the Bab APDGT

I'll follow your results with interest as I just switched over the apdgt plus. I'm keeping my static weight down a bit to my usual to compensate the the xl length. I've got 8 on the handle and another 5g at the tip after 2 weeks of experimenting...so far so good.

The stock SW of the apd+ is 339 so I've got even less room to tinker on that front than you with the std length.

It appears when going to the GT, Bab also moved the balance point from 5pts hl to 4pts on the GT.

Great stick; I used to use the std length one 3 years ago but I like having more mass on it than the stock specs.

[Chapter 24]

Originally Posted by PED

I'll follow your results with interest as I just switched over the apdgt plus. I'm keeping my static weight down a bit to my usual to compensate the the xl length. I've got 8 on the handle and another 5g at the tip after 2 weeks of experimenting...so far so good.

The stock SW of the apd+ is 339 so I've got even less room to tinker on that front than you with the std length.

It appears when going to the GT, Bab also moved the balance point from 5pts hl to 4pts on the GT.

Great stick; I used to use the std length one 3 years ago but I like having more mass on it than the stock specs.

No problem, I would like to be able to help through my own trials and tribulations if possible as I benefit from others' experiences. Maybe you have already run all the numbers but in case you haven't:

(Please keep in mind that I am VERY NEW to all of this so I could be dead wrong in my logic and/or made some calculation errors).

I ran through the all the numbers based on your post and your magic number with this set-up is around 19.35.

I would agree that whatever challenge I face with the non GT version in getting to 21.0 or even close your challenge is much greater.

Also, the GT is 19.6 out of the box so the mods seem to be going in the wrong direction. The non GT is about 20.3 out of the box though mine was about 4 g heavier than listed which helps a little. (Then again, at the same time we have to assume that the SW's we use are reasonably correct which could be a big assumption).

[PED]

Thanks for that, I'm going to put it on the RDC in the next few weeks to get a proper SW number.

I tried the Rafa setup a few years back with 2.5g around the buttcap and 9g at the top of the hoop. Great setup but I like a less head heavy setup for serving and general all court play. It's always fun to try the various possibilities out there. I try to make sure that I don't go too much by the numbers though it's hard some times

[Chapter 24]

Originally Posted by PED

Thanks for that, I'm going to put it on the RDC in the next few weeks to get a proper SW number.

I tried the Rafa setup a few years back with 2.5g around the buttcap and 9g at the top of the hoop. Great setup but I like a less head heavy setup for serving and general all court play. It's always fun to try the various possibilities out there. I try to make sure that I don't go too much by the numbers though it's hard some times

Cool, wish I had one of those. I noticed that the TW University had an APDGT measured at SW=316 (though this same spec is listed in most other places as SW=331) but I'm not going to bank on this because they also had the weight on a unit verified to 310 g where mine is about 324 "naked". So if I am lucky enough that my Bab SW "naked" is actually 316....

Maybe there is enough variation at the Bab factory that you too got a lower SW APDGT Plus

Its pretty amazing how much moving sometimes as little as a couple of grams of weight around changes the feel and the results.

One thing I do know is that I'm now obsessed with trying to find the optimum racquet, string, grip and lead tape set-up for me.

As an aside I would like it if someone started a thread on this MgR/I deal... why then are manufacturers making racquets that are not even close ?

[rromeo]

Originally Posted by travlerajm

To optimize serve speed, I think the easiest way is to notice how high on the fence your ball hits on the fence.

I've found that the priority order of the most important properties for optimizing serve speed are:
1) SW
2) Length
3) Balance.
4) Mass.
They all depend on each other.

Let's assume we are using a midplus headsize (headsize is not that important for serve speed). But the larger your head, the longer your frame will need to be to have equaivalent serving properties. So a 27.5"-long 100sqin frame will have equivalent serving length to a 27"-long 85sqin frame.

SW: For a standard length midplus, I've found the optimum SW for max serve speed is about 360. The optimum SW goes up if you add length. So for 27.5' midplus, the optimum is about 375. For a 28" mp, it's more like 390. When you test, make sure you give your arm long enough to adjust to any added weight, or else you might not notice the benefit.

Length: Longer is better, but only if you increase your SW to stay close to the optimum SW for that length. If you want to remain at low swingweight, you are unlikely to notice any advantage from going to an extended frame.

I recommend trying serves with the butt flare tucked into your palm and your pinky hanging over the end. This will effectively add 3/4" length and approx. 20 SW units. If your serve gets bigger when you do this, then your serve could benefit from extending the handle of your frame.

Balance: The most important thing about balance is that the power potential (ACOR) is optimized for a given SW and mass. The formula for power potential is ACOR = (Ic*COR - mb^2 - Ic/M)/(mb^2 + Ic/M + Ic).

Ic = recoil weight = SW - M(R - 10)^2
SW = swingweight about 10cm axis
M = racquet mass
R = distance from butt to balance in cm
COR = coefficient of restitution = ~0.85
m = mass of ball = 0.057kg
b = distance from impact point to balance point

Mass: Mass is less important as long as the above 3 items are optimized. However, I have found that lighter is a little better. Unfortunately, if you go too light, you need to have a riduculously HH racquet to have ACOR optimized. Even if you are at 12 oz., and the other 3 items are optimized for your serve (this would mean you are playing with Roddick's specs), you would find that the racquet is not balanced very well for groundstrokes, and not HL enough for volleys. So I prefer to keep my serve monster frames at 13 oz or more.

First off, thanks for the reply and detailed info/suggestions. As physics and physiology are my favorite topics, your posts have always been of much interest to me.

I am currently trying to develop a maximum serve power racquet by modifying an old Head TIS2 tweener that I think is a good candidate for customization. Base specs are: 102sqin, 18x19sp, 9.4oz, 312sw, 14.5in bal, 74flex, 27.5in (actually it's 27.25 but will lengthen it to ~27.75). So far I have added lead to the handle and head to bring the specs to: 12.1oz, 360sw, 13.25 bal, w/extra .5in to be added tonite. It is currently strung w/Excel Power 17 prob to be replaced soon w/full gut. This is just for testing, fun, and customizing experience so I really don't care how it performs anywhere except on flat serves. I realize I could prob buy a used or new racquet (Wilson Profile, Yamaha Secret, BabPDR+) that is already a bomb server but that would take most of the fun out of it for me, I'd still end up modding it somehow, and don't think it would end up w/much diff specs.

With regard to power testing by measuring the ball height against the fence, I'm assuming you mean on the fly; if so, what if one can already easily hit the ball over the fence and against the fence/wall in a relatively straight line?? I tried hitting across all 4 courts that I play at and against/over that fence (approx 210') when courts are unoccupied but I don't think thats helpful bcs the higher the launch angle is the more backspin that gets applied and then the distance doesn't necessarily correlate to serve power anymore. Maybe I need to video the flight path or have someone else check how much arc there is, not sure about this.

How would you modify my base TIS2 for max serve power if it was your project and not mine? (I know that's cheating and you prob won't/shouldn't answer)

Thanks in advance for your help/knowledge.

[travlerajm]

Originally Posted by rromeo

First off, thanks for the reply and detailed info/suggestions. As physics and physiology are my favorite topics, your posts have always been of much interest to me.

I am currently trying to develop a maximum serve power racquet by modifying an old Head TIS2 tweener that I think is a good candidate for customization. Base specs are: 102sqin, 18x19sp, 9.4oz, 312sw, 14.5in bal, 74flex, 27.5in (actually it's 27.25 but will lengthen it to ~27.75). So far I have added lead to the handle and head to bring the specs to: 12.1oz, 360sw, 13.25 bal, w/extra .5in to be added tonite. It is currently strung w/Excel Power 17 prob to be replaced soon w/full gut. This is just for testing, fun, and customizing experience so I really don't care how it performs anywhere except on flat serves. I realize I could prob buy a used or new racquet (Wilson Profile, Yamaha Secret, BabPDR+) that is already a bomb server but that would take most of the fun out of it for me, I'd still end up modding it somehow, and don't think it would end up w/much diff specs.

With regard to power testing by measuring the ball height against the fence, I'm assuming you mean on the fly; if so, what if one can already easily hit the ball over the fence and against the fence/wall in a relatively straight line?? I tried hitting across all 4 courts that I play at and against/over that fence (approx 210') when courts are unoccupied but I don't think thats helpful bcs the higher the launch angle is the more backspin that gets applied and then the distance doesn't necessarily correlate to serve power anymore. Maybe I need to video the flight path or have someone else check how much arc there is, not sure about this.

How would you modify my base TIS2 for max serve power if it was your project and not mine? (I know that's cheating and you prob won't/shouldn't answer)

Thanks in advance for your help/knowledge.

By power testing on the fence. I mean hit a serve that lands in the service box, then notice high on the fence it hits after the bounce. A standard fence is 21 ft behind the baseline, so your bounce height can be compared on different courts.

I think you're on the right track toward creating your evil serve monster.

I'm about to embark on the same project (creating the ultimate serve onster) - just picked up a new O3 Red for the purpose. First step is to extend the length out at least 1/2 in. Then lead it up into the right SW neighborhood with some counterbalance too.

[travlerajm]

Originally Posted by Chapter 24

Maybe for travlerajm who has an awesome amount of tennis knowledge ! (Thanks again for your posts if I have failed to thank you sufficiently up to this point):

I know that you there is a good chance you aren't medically qualified to provide an answer to this question (then again, I could be wrong about that too !!) but just from a tennis/physics point of view, would my wrist problem when serving/overheading that I referred to above be caused/aggravated by total weight or swingweight or perhaps both.

If this helps it hurts the area in the joint specifically on top of my wrist when I push on the front of my finger tips and try to bend my hand backwards towards the top of my forearm. When I serve/overhead I feel this exact same strain.

I don't know the answer to your question, but I believe I had that same injury. I played a 3-set tournament match after not touching a racquet all summer. Then the next day, I tried to shift my car from first to 2nd, and something popped in my wrist! I think it was your typical overuse strain - it heals with a few weeks of rest. The key is ramp up slowly and don't overdo it. I'm guessing that once it's fully healed, your racquet specs won't be the problem.

[rromeo]

Originally Posted by travlerajm

By power testing on the fence. I mean hit a serve that lands in the service box, then notice high on the fence it hits after the bounce. A standard fence is 21 ft behind the baseline, so your bounce height can be compared on different courts.

I think you're on the right track toward creating your evil serve monster.

I'm about to embark on the same project (creating the ultimate serve onster) - just picked up a new O3 Red for the purpose. First step is to extend the length out at least 1/2 in. Then lead it up into the right SW neighborhood with some counterbalance too.

Interesting, very similar specs to my TIS2 except for the RDC rating (74vs67) and string pattern.

About the ball bounce, though, I have read that it is a very inaccurate way to determine serve speed due to the additional variables mixed in like court speed, bounce location and angle. Do you disagree and what about straight against the wall/fence??

Ultimately I'm prob gonna need either an assistant w/a stopwatch or a radar gun, or a video camera.

[Chapter 24]

Originally Posted by travlerajm

I don't know the answer to your question, but I believe I had that same injury. I played a 3-set tournament match after not touching a racquet all summer. Then the next day, I tried to shift my car from first to 2nd, and something popped in my wrist! I think it was your typical overuse strain - it heals with a few weeks of rest. The key is ramp up slowly and don't overdo it. I'm guessing that once it's fully healed, your racquet specs won't be the problem.

Thanks, that sounds like a reasonable assessment !!

[Pioneer]

Originally Posted by rromeo

First off, thanks for the reply and detailed info/suggestions. As physics and physiology are my favorite topics, your posts have always been of much interest to me.

I am currently trying to develop a maximum serve power racquet by modifying an old Head TIS2 tweener that I think is a good candidate for customization. Base specs are: 102sqin, 18x19sp, 9.4oz, 312sw, 14.5in bal, 74flex, 27.5in (actually it's 27.25 but will lengthen it to ~27.75). So far I have added lead to the handle and head to bring the specs to: 12.1oz, 360sw, 13.25 bal, w/extra .5in to be added tonite. It is currently strung w/Excel Power 17 prob to be replaced soon w/full gut. This is just for testing, fun, and customizing experience so I really don't care how it performs anywhere except on flat serves. I realize I could prob buy a used or new racquet (Wilson Profile, Yamaha Secret, BabPDR+) that is already a bomb server but that would take most of the fun out of it for me, I'd still end up modding it somehow, and don't think it would end up w/much diff specs.

With regard to power testing by measuring the ball height against the fence, I'm assuming you mean on the fly; if so, what if one can already easily hit the ball over the fence and against the fence/wall in a relatively straight line?? I tried hitting across all 4 courts that I play at and against/over that fence (approx 210') when courts are unoccupied but I don't think thats helpful bcs the higher the launch angle is the more backspin that gets applied and then the distance doesn't necessarily correlate to serve power anymore. Maybe I need to video the flight path or have someone else check how much arc there is, not sure about this.

How would you modify my base TIS2 for max serve power if it was your project and not mine? (I know that's cheating and you prob won't/shouldn't answer)

Thanks in advance for your help/knowledge.

Hey, I'm trying to make a serve monster out of an old cracked and repaired Head LM Fire. It's 102sq. in. but head measures it from the outside so it's more like 98sq. in. As for weight and SW I have no Idea but it's pretty close to even balance and it's 27.25 in. but I might extend it to 27.5 in.

Please let me know how your mods go

PS: All the mods are gonna be done with duct tape for now because all the lead is on my H19

[pennc94]

Just watched Denis Kudla practice before his qualifier match at Legg Mason.

His spare racquets (Tecnifibre T-Fight 325 Vo2Max) had stickers from his customizer:

Mass: 332g, Bal: 31.4cm, SW: 298

I am not sure if those are unstrung specs.