Swingweight Question - MgR/I

Discussion in 'Racquets' started by normrose, Feb 4, 2011.

  1. normrose

    normrose Rookie

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    I have read threads by Travlejam and Corners on the subject of lead placement at 7 inches from the butt in order to bring the head of the racquet around more quickly.

    I gained the impression from different threads it was the forehand stroke that was the main beneficary. Does the one handed backhand, volley and serve also benefit from this type of lead placement?
     
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  2. whomad15

    whomad15 Semi-Pro

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    I would assume so, racquet mobility would be a general thing, so if you're having trouble getting the racquet around that sounds like it should help.
     
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  3. user92626

    user92626 Legend

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    I think if you can get the racket head going around quicker for FH, it stands to reason that it's also applicable for other strokes, assuming the weight hasn't past the threadhold of your strength.

    Anyway, if you want even quicker racket head speed, try placing lead at 12 instead of the 7" from buttcap. You could even use less lead, resulting in less static weight, thus less tiring.
     
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  4. cellofaan

    cellofaan Semi-Pro

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    MgR/I is supposed to work for at least forehands and backhands. I don't recall travler saying much about MgR/I in relation to the serve, though he has posted theories on optimizing serve speed in earlier SW2 threads. I do recall travler posting that he usually starts optimizng MgR/I for his forehand, and then adjusts it for his 2 handed backhand (axis of rotation at a different spot) by placing lead at the buttcap, which doesn't affect MgR/I for the forehand.

    For a onehanded backhand I suppose MgR/I should work the same as a forehand.

    This is actually almost opposite of what MgR/I would suggest. A higher SW lowers MgR/I, while a higher static weight raises MgR/I, and a higher value means faster natural swing speed of the racquet.
    MgR/I is meant to make the swing feel more natural, making it more repeatable, rather than less tiring.
     
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  5. normrose

    normrose Rookie

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    Thanks Cellofaan for the clarification.

    One other point - would it be right to assume the more weight added 7 inches from the butt, provided it is comfortable, would make the frame swing speed faster?
     
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  6. corners

    corners Legend

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    I think that higher MgR/ for a given mass and swingweight won't really result in faster swingspeed. Rather, the tip will move faster in relation to the hand/handle - so it's more about timing than absolute speed.
     
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  7. normrose

    normrose Rookie

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    Thanks Corners for your comment - I shall start to experiment.
     
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  8. Nor'easter

    Nor'easter New User

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    Can anyone tell whether I've achieved the optimal MgR/I for my racquet? I'm sorry, but I'm not sure how to compute it exactly.

    Stock racquet:

    static weight 320 gm
    4pt HL
    SW 328

    I've added 10gm lead tape to handle 8.5" above butt cap. I tried it for the first time today and noticed I had better timing on forehands (improved moment of inertia?), but felt as though I had less plowthru. Also, have I effected the sweetspot any by adding the lead?


    Thanks for your input.
     
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  9. psycho0

    psycho0 Rookie

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    The equation: Swingweight+(20*Mass*Balance)-(100*Mass)=I
    MgR/I=

    4pts HL = 33.02cm balance

    328+(20*0.32*33.02)-(100*0.32)= 507.33
    MgR/I = (0.32*980.5*33.02)/507.33
    MgR/I = 20.4

    Hopefully that made sense to you. Btw, all units are in metric values. Mass in kilograms and balance in centimeters
     
    Last edited: Feb 7, 2011
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  10. Nor'easter

    Nor'easter New User

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    Thanks for the quick response. I am assuming that is the MgR/I value is for the stock raquet. How do I calculate in the 10gm lead at 8.5" above the butt cap for a new MgR/I value? I read somewhere in this forum that a MgR/I value of 21.0 is ideal. How do I get there?

    Also, do you know what the new balance point of the racquet is with the lead tape I've added?

    Thanks again for your help!
     
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  11. Don't Let It Bounce

    Don't Let It Bounce Hall of Fame

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    I haven't done this sort of experimentation, and I don't even have an opinion on how helpful it is, but from what I've read of Travlerajm's very interesting posts on the topic, no one can tell you if your balance is optimized.

    I believe the idea is to calculate the above ratio and then to test for yourself what minor adjustments, if any, make the swing feel effortless. Once you've found that feeling, you note what the ratio is (it might be 21.0, but it might be a little different, and I think Travlerajm has suggested it varies based on arm length) and use that to customize other racquets that have difference specs.

    If I've misunderstood the general idea, someone please correct me.
     
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  12. psycho0

    psycho0 Rookie

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    Go to this website: http://twu.tennis-warehouse.com/learning_center/customizationReverse.php

    Enter your current racquet specs and then make modifications accordingly. After it gives you the modified specs, use the MgR/I formula to calculate your value. Find the weight that will produce an MgR/I value of 21.. it takes a few trials. Btw, the best place to increase MgR/I is 7" from the buttcap, 8.5" might be a little too high.
     
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  13. cellofaan

    cellofaan Semi-Pro

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    That's correct. The ideal value will change between different players, but is expected to be somewhere in the neighbourhood of 21, which would therefore be a good starting point.

    I think he also mentioned that grip (eastern (semi)western) can be of influence, since optimal contact point is different depending on your grip.


    Essentially, there are all those little things that make one player different from an other, and optimum MgR/I is one of them. And they all influence each other.
     
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  14. Sreeram

    Sreeram Professional

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    My backhand struggles a lot with a racquet that is more than 8 pts HL. I play double handed BH. I think it is about getting used to them. But forehand and serve are good with the wip effect.
     
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  15. floydcouncil

    floydcouncil Semi-Pro

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    So... you're going to add weight ABOVE your hand to make the head of the racquet swing FASTER?

    Crazyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy!
    If this isn't a contradiction to all laws of physics, I don't know what is.
     
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  16. Nor'easter

    Nor'easter New User

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    Thanks again. After using the TW customization tool and the MgR/I equation, I came up with 18 gm lead tape at 7" from butt cap will give me 20.9. Swingweight becomes 329, balance point 32.21cm=6.6 pts HL.

    I will give this a go.
     
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  17. psycho0

    psycho0 Rookie

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    Sounds good. Let us know how it plays!
     
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  18. TaihtDuhShaat

    TaihtDuhShaat Semi-Pro

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    Got Curious

    Well I've been adding weight inside the buttcap, and the more I add the weaker the racket head has been feeling thru the ball. From trial and error without know about the equation my setup was 346g, 329 sw, and 31.5cm balance which gave me a value of about 20.86.

    So I added the weight to 7" from the buttcap.

    Now it's 346g,330sw, and 32cm which gave me a MgR/I of about 21.

    Dry swinging around the house it feels much lighter and effortless.

    I'll report back with results, but is this something the racquet companies use in their frames?
     
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  19. cellofaan

    cellofaan Semi-Pro

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    Perpetuum mobiles are.

    Actually, if you do the swingweight measurement from TWU, you'll see that a racquet with 330grams static weight, 32cm balance and 300 SW has a shorter swingtime than a 330 grams 31cm 300SW racquet.

    So yes, adding lead at 7.9inch will make it swing faster than adding it at the buttcap.


    Crazy huh, physics?
     
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  20. olliess

    olliess Semi-Pro

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    Yeah but that's because the 31 cm (more headlight) racquet needs to be more polarized (more weight away from the balance point) to achieve the same swingweight as the 32 cm racquet, right?

    Crazy indeed. ;)
     
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  21. cellofaan

    cellofaan Semi-Pro

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    Usually yes, but you seemed to imply that adding weight below your hand (to the butt) would result in a faster head speed compared to adding it on top of the grip, above your hand. And that's not true.

    If you start with two of the same racquets, adding lead to the butt will always make it more polarized than adding it on the top of the handle, and the one with lead at the top of the handle will 'always' swing faster (at least for all the combinations I tried on the calc).
     
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  22. olliess

    olliess Semi-Pro

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    No implication was implied, I was only replying to your specific example.

    Let me understand this correctly: are you saying that, when you suspend the racquet from the upper strings as described on the TWU swingweight calc page, adding a weight higher on the handle (closer to the pivot) rather than lower (further from the pivot) makes the swing period shorter ("swings faster")?
     
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  23. cellofaan

    cellofaan Semi-Pro

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    Yes.
    But only if static weight and SW are comparable between the two.
    For example placing lead at 0" and at 8", the 8" version will have a shorter swing period.

    However, if you would compare adding lead at 0" versus 13", the SW of the second will be higher, and in that case, swing period could be faster for the 0" version, as that one will have a lower swingweight.
     
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  24. olliess

    olliess Semi-Pro

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    I must just not be "getting" what you are describing.

    The swingweight (RDC) and the pendulum period (per the TWU method) are measured from the opposite ends of the racquet. Adding the same lead at 0" instead of 13" makes for a "longer" pendulum, so I can't understand why it would it also shorten the swing period!
     
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  25. cellofaan

    cellofaan Semi-Pro

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    I think you can't really simplify it to a regular pendulum, as a regular pendulum has all its mass focused at 1 point, while a racquet has weight distributed throughout the entire frame. Inertia (SW) is then not a direct function of the balance point and static weight.

    So while you are correct that the 'length' of the pendulum is shorter for lead at 13" compared to 0", the increase in SW will be larger for the lead 13".
    So then you'd be comparing a longer pendulum with lower inertia, to a shorter pendulum with a higher inertia.
    Making the pendulum longer slows down the swing for the first racquet, but the larger increase in swingweight for the second racquet also makes its swing slower.
    So somewhere there is a break-even point for which the increase in SW has more effect than the lowering of the balance point, or vice-versa.

    I honestly can't explain it much better than this, as I'm not that much into pendulums and stuff. Maybe corners can chime in on the subject?



    Oh and about measuring from the opposite sides. You could suspend the racquet from the 10cm axis instead of the top cross string, and still use the TWU method.
    The SW value will then come out negative since one part of the formula becomes negative (as they calculate the distance between the balance point and the axis of rotation by substracting them from each other without checking which one is the higher value, and it thus results in a negative distance, while distance should always be positive).
    Even then, a lower balance point results in a slower swing, even though the pendulum is shorter.
     
    Last edited: Feb 9, 2011
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  26. i suck at tennis

    i suck at tennis Rookie

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    Will a racquet for which MgR/I of 21 is attained by adding weight at 12 and toward the bottom of the handle have the same attributes (not sure if that is the exact word I should use) as the same racquet for which MgR/I = 21 is attained by adding lead 7 inches up the handle??

    Ex., I was playing around with the formula in an Excel sheet and using the specs I came up with, the TW customization tool told me to add weight at 12 and towards the bottom of the handle. The racquet I was using as a base was the YT Prestige MP. The sheet is on my computer at work so I don't have the exact figures with me at the moment.
     
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  27. TaihtDuhShaat

    TaihtDuhShaat Semi-Pro

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    Whoa!


    Wow! It was better at volleys, and came around more easily on groundstrokes, all with LESS of a headlight balance. The racket feels much more dialed in and easier on the body than the way I had it with 10g in the buttcap. I wonder if the racket companies add weight in the 7" region when they design headlight sticks.
     
    #27
  28. CCH4TENNIS

    CCH4TENNIS New User

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    Hi

    Where does the 980.5 in the formula MgR/I = (0.32*980.5*33.02)/507.33 come from ?

    Thanks
     
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  29. Shroud

    Shroud Hall of Fame

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    #29
  30. Shroud

    Shroud Hall of Fame

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    2 questions:

    1. Can someone check my math?

    Mass: .3671kg
    SW: 330
    Balance: 28.99 cm

    I: 330+ (20*.367*28.99)-(100*.3671)= 506.13

    MgR=(0.3671*980.5*28.99)= 10,434.7

    10,434.7/ 506.13= 20.6


    2. If I put say 12-15g at 7" from the buttcap would that make it 21? And should I slowly do this or jump to 21?

    3. And doesnt arm length need to be taken into account along with sweatbands? What if you are wearing sweats, etc.
     
    Last edited: Apr 23, 2014
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  31. morten

    morten Hall of Fame

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    I often put a coin at 7'.. And the racket feels so much more like an extension of my arm, more connected in a way. And after the forehand takeback, as i push hand foreward, the extra weight at 7' slows down the hand, so that the head will not come around sluggish and feel more head heavy. I also read this trick in an old tennis book. So few people know about this, it can really change a racket for the better.
     
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  32. newyorkstadium

    newyorkstadium Semi-Pro

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    You need this

    https://docs.google.com/spreadsheet/ccc?key=0AgowZT0_5hPGdHhfMTd5d1FXTHJHNWZYZ251b04ydWc#gid=0

    Then this

    http://twu.tennis-warehouse.com/learning_center/customizationReverse.php

    It is established that all of those affect MgR/I, as well as forehand grip and possibly swingweight.

    Travlerajm estimated the effects of wristband, forehand grip and arm length, on MgR/I, from the differences between pro's racket specs. Though, I don't think you can extrapolate the effects of a single factor like wristband, based on differences in the pro's MgR/I. The pro's in the no wristband group and pro wristband group could also have different arm length and forehand grips, which also affect MgR/I. You would need to actually know how these factors affect MgR/I, then input it into the data. Experimenting by wall-testing would be far more accurate. I tried, but got nowhere.

    Anyway, here are travlerajm's estimates, which I think I have proved to be inaccurate.

    Single-Wide Wristband - lowers 0.1
    Double Wide Wristband - lowers 0.2
    Going from eastern grip to SW grip - lowers 0.2
    Going from SW grip to W grip - lowers 0.2
    Any impact of swingweight is currently unknown.

    I would love it if travlerajm replied to rebuke this, but he is impossible to get hold of. At present, the only way to find out your personal MgR/I is to experiment against a wall - http://tt.tennis-warehouse.com/showpost.php?p=5859118&postcount=17
     
    Last edited: Sep 5, 2014
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  33. Shroud

    Shroud Hall of Fame

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    Thanks alot this was helpful and looks like my math was right.

    I did see trav on the string section the other day so maybe he will see this.

    Also if I understand things then I actually need to shoot for higher than 21 to take into account my wristband, etc. Or should I just hit against the wall and slowly add weight till it clicks?
     
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  34. corners

    corners Legend

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    I think Mr. Stadium has the sign backwards on those factors. Wearing a wristband increases MgR/I. So if your stick is 21.0 it will effectively be 21.2 when you wear a wristband. Not sure what the sign should be for the grip adjustments, etc.
     
    #34
  35. corners

    corners Legend

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    Yeah, I also use coins and get the same feeling as a result that you describe. Lately, I've switched from coins to bluetak. You can pinch off a 5g or 10g chunk of bluetack, stretch and flatten it into a band and wrap it around the top of the grip. Advantage is that you don't need tape to fix it to the handle and so you can quickly remove, add, adjust, etc.

    I think this is a great and easy way for people who have been curious about Trav's MgR/I stuff, but put off by the math or whatever, to try it out. Just 5-10 grams added at the top of the grip noticeably changes the way a racquet feels to swing. The same amount added to the butt does not have the same effect, not at all.

    Interesting. Do you think you could recall what book you read it in? There was an infamous but quite interesting poster on these boards some years back, John Cauthen, who was a strong advocate/evangelist for adding weight at the 7" point. He was all about cutting lead sheet metal into 40-50 gram pieces and taping it to the top of the grip. I wonder if he first got the idea from the same book(s) that you saw the coin trick in.
     
    Last edited: Apr 24, 2014
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  36. avince

    avince Rookie

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    Could you explain the difference in feel between lead at the top of the grip and added to the buttcap ?
     
    #36
  37. corners

    corners Legend

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    As morgen described a couple posts up, weight at the top of the grip seems to make the head of the racquet "come through" the swing quicker. Another way to say this is that the head seems quicker in relation to the hand. The opposite feel from this for me is adding weight to the tip of the racquet. That way, the head feels slower through contact in relation to the hand. There is a sense that the head is lagging far behind the swing, even if I'm not trying to create that with the way I'm swinging. Adding mass at the top of the grip quickens the head. So if I add a couple grams to the tip to increase swingweight and plow through, I'll add about double that amount to the top of the grip to keep the timing of the swing the same.

    Adding mass to the buttcap does not have this effect for me. In fact, adding mass to the buttcap gives me a feeling that the entire racquet slows down, just a tad. Keep in mind that this is all about rotational swings. For volleys, where the racquet is not really swung in an arc, but rather punches or pushed in a more linear stroke, weight in the buttcap makes it feel more maneuverable, for sure.

    But try it yourself. Get yourself some bluetack:

    1. Add 5-10 grams at the top of the grip and see how it affects your swing. Does it feel quicker or easier to swing? Does this seem to complement your swing style and timing?

    2. Then take it off and see how it feels.

    3. Then add a little ribbon of bluetack to the tip, wrapped around the frame between the center mains. How does that feel?

    4. Then add about twice that amount to the top of the handle. Does it now feel easier to swing again, as though the mass added to the tip has been "neutralized"?


    The poster travlerajm developed his MgR/I hypothesis by viewing groundstrokes as a double pendulum system. Adding mass to the top of the grip increases the natural frequency of the hand/racquet part of this system (the lower pendulum). So if his hypothesis is correct, it explains my perception of how mass at this location affects my swing. But just because it works for me doesn't mean the hypothesis is correct. You might have a different experience. And even if you do have a similar experience there are other ways to explain these results. I happen to favor his hypothesis, but the more "data" we get on this from players, the better. Please share your results if you decide to play around these ideas.
     
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  38. Irvin

    Irvin G.O.A.T.

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    When measuring swing weight the standards are to measure the swing weight at either 4" or 10 cm from the butt cap but swing weight could be measured from any point. The farther out or above the pivot point the more force is required to move or swing that weight. The more weight below the pivot point the less force is required to swing the weight. You still have the weight to contend with but the ability to rotate the weight around the pivot point depends a lot on where it is located.

    Most people though probably will not a notice the difference between small amounts of weight either a few inches above or below your pivot point.
     
    #38
  39. BlueB

    BlueB Hall of Fame

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    Corners, interesting, my experience is exactely opposite... Higher MgR/I number equaled slower head speed. I used the weight between grip and lower hoop to make racquet more controlled, whipping slower through the contact zone. Isn't a more polarised frame whippier?
     
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  40. newyorkstadium

    newyorkstadium Semi-Pro

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    Wristbands do lower MgR/I according to travlerajm, Shroud. I would paste the link, but I can't do that on the device I'm using.

    21 is just the number that worked for travlerajm. Everyone has different equipment factors like wristbands, swingweight, choking up the handle and forehand grip. No-one knows how these influence MgR/I. Travlerajm estimated some from the MgR/I data of the pro's. I proved these estimates to be innacurate in my post above. In fact one of the MgR/I detractors kaiser said of travlerajm's Pro spec analysis, that he was "torturing the data till it agreed with you". I would agree with this. Shroud, there is link to instructions on how to wall tune in my post above.

    I completely agree with corners. What we need is data from people who have succesfully tuned their MgR/I. I tried this in my "questions for travlerajm", but got nowhere. I will post the data if anyone is interested.

    Does anyone know where I can get accurate pro players specs? I wouldn't mind trying to draw something from the pro specs. As mentioned above though, the best and most accurate way to find out how the different equipment factors affect MgR/I would be to experiment with wall tuning. I tried and got nowhere.
     
    Last edited: Sep 5, 2014
    #40
  41. Shroud

    Shroud Hall of Fame

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    Man I used to be good at math.

    So I added 14g at 7". Recalculated the SW and somehow its LOWER now by 10pts.

    I thought that was impossible so I must have screwed up. Any thoughts on how.

    New values are:

    Mass: 381.4
    Balance point: 28.57 cm
    Distance to hang string 25"
    10 swing avg: 14.06

    Though now the mgr/I is 21.38 :)

    It was really strange. Shadow swinging adding the weight seemed to make the racket a bit tougher to get started but the swing seemed a bit more fluid and it was like there was a force PUSHING the racket head forward right before contact.

    Must hit and see.
     
    #41
  42. travlerajm

    travlerajm Hall of Fame

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    It's actually possible to tune your MgR/I value by shadow swinging with a pendulum sweep type swing (high-to-low-to-high with a relaxed wrist).

    If you feel the racquet applying a torque that pulls your hand forward through the contact zone (as you are describing), that's an indication that the MgR/I is too high (which is supported by your measurements). A racquet with MgR/I that is too high is very difficult to play with because it's not natural to pull back with the wrist muscles to compensate while swinging forward toward the ball.

    If MgR/I is too low, you will feel a torque pushing back on your hand as the racquet lags through the contact zone. Most stock racquets are set up this way, forcing the user to apply a torque from the wrist muscles to compensate.

    If MgR/I is tuned perfectly, you should feel a net zero torque transmitted from the racquet to the hand as you come through the hitting zone. When this is the case, you don't need to use your wrist muscles to control your racquetface, and controlling your shot becomes much easier and more natural. Accuracy will be better, and your arm will not get tired because you can relax the wrist muscles through the swing and let the larger muscles of your body, along with gravity, do the work.
     
    #42
  43. newyorkstadium

    newyorkstadium Semi-Pro

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    Travlerajm, I don't think your estimates for the various equipment factors, like wristbands and SW grip, are accurate for the reasons quoted below. I also don't think the bar charts you used, that showed a correlation between pro ranking and MgR/I, are accurate, as you didn't factor in things like wristbands, grip size, swing-weight or choking up the handle. Do you still have the list of pro specs, perchance? I wouldn't mind trying to draw something from the data. I've found some pro specs, but most don't give the swingweight for some reason.

    As I've mentioned in the past, I would be interested in creating a spreadsheet that calculates an individuals personal MgR/I value, based on arm length and the equipment factors. I think there is the potential for MgR/I to really take off if we know these things.

     
    Last edited: Sep 5, 2014
    #43
  44. corners

    corners Legend

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    One poster, I think Fed Kennedy, once described a depolarized setup as swinging "slappy", while a polarized one swung "whippy." I'm not sure, if the swingweights are the same, that a higher or lower MgR/I ratio will result in high or lower peak swingspeed. I'm talking more about timing - the feeling of how much and/or for how long the head lags behind the handle during the swing. Since lagging the head to load the stretch-shortening mechanisms in the forearm and shoulder are so important to generating lots of RHS in the modern forehand, a low MgR/I setup might facilitate that, for some players. For me, though, too much lag is a bad thing. I actually feel such setups stress my shoulder more than a high MgR/I setup.

    But I totally accept the possibility that this might be more a matter of individual differences in anatomy and technique rather than double pendulum physics.
     
    Last edited: Apr 25, 2014
    #44
  45. travlerajm

    travlerajm Hall of Fame

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    I haven't been on a tennis court much over the past few months, but I've still been bringing my racquet to the gym to hit against the wall inside the racquet ball court.

    This has given me time to work on correcting a flaw in my forehand technique... a flaw that is deeply ingrained in my muscle memory from 30 years of hitting forehands with ill-advised form.

    My regular forehand is cramped, with the contact point closer to my body than it should be. I've been working on moving my contact point further out (about 4-6") more extended. I suppose this is closer to straight-arm technique than my habitual cramped double-bend.

    What I've found is that the straighter-arm forehand (aside from giving me more leverage and racquethead speed and feeling really sweet when I time it right), is less sensitive to MgR/I.

    With my habitual cramped double-bend form, my MgR/I needs to be 21.0 on the nose for me to feel confident in my stroke.

    With the more extended straighter arm technique that I'm trying to develop, 21.0 still works great and feels right. But it also seems to work ok for MgR/I values as low as 20.8. It does seem to tire my wrist a little at 20.8, but unlike with the cramped form, I can still feel like I can control the ball ok at that value.

    I haven't yet experimented to optimize MgR/I with the straighter arm technique. And of course, many of my forehands while I'm practicing are hit somewhere in between these two extremes (as the cramped-form habit is hard to break).
     
    #45
  46. corners

    corners Legend

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    Trav, good on ya for continuing to tweak your forehand technique. I recall that that's always been your weaker wing. I also hit a pretty strong double-bend before returning to tennis some years ago. After picking up a racquet again that cramped feeling really bothered me, especially when compared to the free and open feeling I have when hitting over the OHBH. So I totally revamped the stroke and now hit with a straighter arm, pretty much straight on high balls.

    Interesting that you found a larger range of ratios to work with your new technique. I still prefer 21.2, but have a couple new sticks that are 20.8 stock and I can still swing them OK. Some days I think, maybe, that I prefer them. But I also haven't been playing enough to really judge accurately.
     
    Last edited: Apr 25, 2014
    #46
  47. Shroud

    Shroud Hall of Fame

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    Cool thanks for the reply and good for you tweaking the forehand. I am starting a similar journey and yesterday was the first time the straight arm fh made sense.

    Anyhow sorry to ask such a simple question but does adding more weight at 7" make MgR/I go up or down??
     
    #47
  48. corners

    corners Legend

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    7" - up, tip - down, butt - no effect
     
    #48
  49. Shroud

    Shroud Hall of Fame

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    Thanks!!!

    I tried it normal, 7g at 7" and 14g at 7".

    I really can't tell much of a difference...well they feel different but I cant say which is better.

    Anyhow tips?
     
    #49
  50. corners

    corners Legend

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    Maybe we're talking from different reference frames or something. If I am using a frame at 20.8 and then put on a wristband, the effective ratio will now be 20.0, +0.2.

    http://tt.tennis-warehouse.com/showpost.php?p=7032238&postcount=254
     
    #50

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