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#1 |
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Hall Of Fame
Join Date: Sep 2007
Location: 香格里拉
Posts: 2,062
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I noticed some of my racquets head are shortened by a couple of mm longitudinally after strung. When I string I make sure racquet is mounted properly, and I dont have too much of a tension difference in mains/crosses - e.g. M:gut54/X:poly50. What else could contribute to the head compression? Thanks.
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| Shangri La |
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#2 |
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Legend
Join Date: Feb 2004
Posts: 6,961
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Cheap machine that isn't that sturdy. If it's a Head racket, you may want to try stringing the crosses a little tighter than the mains.
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| Steve Huff |
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#3 | |
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Professional
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Quote:
Not a problem. But if you're curious, you can decrease main tensions and/or increase cross tensions to even them out.
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"Physics is like sex: sure, it may give some practical results, but that's not why we do it." -- Richard P. Feynman |
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#4 |
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Legend
Join Date: Mar 2007
Location: Marietta, Ga
Posts: 7,053
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The mutual forces of action and reaction between two bodies are equal, opposite and collinear.
When you string a racket on a two point stringer the two points support the racket from bending inward. Many inexpensive two point machine do not hold well. When you string a racket on a six point stringer the two points at the top and bottom support the racket from bending inward. As the frame tries to bend inwards from the top and bottom the sides try to bend outward. The four supports on the sides of a six point support the racket from bending outward and help prevent the frame from bending inward from the top and bottom. If your racket is shorter it is wider too or more circular. This causes the racket to be under stress while you are playing with it because the strings are what is keeping the racket deformed. Therefore, there is more tension on your main strings that you have on the crosses because the frame is trying to return back to it normal state. Irvin
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Irvin - I wish Facebook would notify me when people delete me so I can 'Like it' |
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#5 |
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Professional
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I don't believe it's due to the mounting.
I believe it is a simple fact that, it is nearly impossible to find the perfectly equalizing tension, such that the compressing force from the mains cancels out exactly the elongating force from the crosses.
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"Physics is like sex: sure, it may give some practical results, but that's not why we do it." -- Richard P. Feynman |
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#6 |
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Legend
Join Date: Mar 2007
Location: Marietta, Ga
Posts: 7,053
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^^If that were true since there are more crosses than mains the greater force would be on the sides and you would have a longer racket.
Irvin
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Irvin - I wish Facebook would notify me when people delete me so I can 'Like it' |
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#7 |
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Professional
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Due to the substantial amount of friction caused by the mains when a cross is strung, the tension actually "felt" by the cross string and the racquet is less than the force that you're pulling it.
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"Physics is like sex: sure, it may give some practical results, but that's not why we do it." -- Richard P. Feynman |
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#8 |
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Legend
Join Date: Mar 2007
Location: Marietta, Ga
Posts: 7,053
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This may help you if it is not a mounting issue. Some people seem to really like it.
http://tt.tennis-warehouse.com/showt...13#post5868113 Irvin
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Irvin - I wish Facebook would notify me when people delete me so I can 'Like it' Last edited by Irvin : 07-30-2011 at 03:25 AM. |
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#9 |
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Hall Of Fame
Join Date: Jan 2009
Posts: 1,845
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Irvin is correct, it's all about the mounting. I've restored more than a few shortened/deformed frames, mostly Head frames, back to original by simply 'stretching' the frame by the exact measurement. Btw I use a 6-pointer and I'm not sure if it'd work with a 2-pointer. So for example if it's 2mm short, just stretch the frame by 2mm with the 12 o'clock mount the next time you string it and it will come out perfect, trust me. Also it depends on your machine. On certain 6-pointers, there is more flex than usual and the frame needs to be stretched a few mm's for every stringjob to ensure it comes out the same.
Regarding the tension for mains and crosses, it's not really an issue if the difference is not too big. Even with Head frames I've done the crosses 3-4 lbs lower than the mains in a full-bed setup before (same string both mains and crosses) and with the correct mounting it always comes out perfect. I'd imagine the frame would start to deform if the difference is like 8 lbs in a full-bed setup.
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Head PT630/280. Last edited by MarrratSafin : 07-30-2011 at 02:25 AM. |
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#10 | |
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Hall Of Fame
Join Date: Feb 2004
Posts: 4,348
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Quote:
In most cases it is due to a certain type of frame (some of the Heads) and a poor mounting/support system.. or just bad mounting by the user. If you are using a Klippermate or one of lower end 2-point systems.. there is your problem. You will indeed need to stretch the frame when mounting. The question has been asked many.. many times. All the Klippermate users will swear it never happens to them. Do a Head Radical on a Klippermate and you will get compression unless you stretch the frame when mounting. I moved from a Klippermate to a 6-point Alpha and have never seen the problem since. Not once.. |
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#11 |
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Hall Of Fame
Join Date: Sep 2007
Location: 香格里拉
Posts: 2,062
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Thanks for all the advice guys. I have a Silent partner swing, which is basically a 2-point system. I don't want to string cross tighter because of the string bed feel. I have this shortening problem with a HEAD prestige youteck and POG OS, but not on Boris Becker London. And I *think* the HEAD and POG, when previously strung by pro/TW, didnt have this problem.
I've thought about but am hesitant to stretch the frame longitudinally when mounting, because I think it will completely screw up the tensions. What I'm thinking of doing are - Not increasing the tensions of the last mains when tie off. I always increase 10 lbs to compensate for tension loss but I dont think last main tension matters to performance. - Increasing the first and last 2 or 3 crosses tension by 1 to 2 pounds. By doing so I will reduce the longitudinal tension by about 25 lbs which should help. |
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| Shangri La |
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#12 |
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Rookie
Join Date: Apr 2011
Posts: 101
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I just finished stringing my head youtek radical pro. the frame is now wider. Can you please explain the stretching of the head process. I am using a gamma x-2
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Head Youtek Radical Pro Gamma x-2 machine |
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#13 | |
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Talk Tennis Guru
Join Date: Jul 2007
Location: San Diego, CA
Posts: 29,087
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Quote:
Next time, string the crosses 10 lbs. higher and the frame won't round out or shorten by a couple mm. |
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#14 | |
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Rookie
Join Date: May 2010
Posts: 235
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Quote:
It's one thing when a company is known for poor quality and bad service. Klipper is not one of those companies. |
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#15 |
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G.O.A.T.
Join Date: Feb 2004
Location: at the bottom of every hill I come to
Posts: 11,150
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I really can't believe some of what I'm reading. I string on a Neos and have never had a Head racquet "compress", or any other kind of racquet. Stringing 10 pounds higher to compensate? What of the end result?
Guys, short of it is, anytime a racquet compresses or shifts or the shape is different, then it is NOT a good thing. It's hard enough on a frame just stringing it normally, but all these suggested "fixes" are just plain scary. The problem here is either the mounting system used, or the way in which the frame was mounted.
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Wilson Steam 99S poly Luxilon 4G 1.25 @ 45 |
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#16 | |
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Legend
Join Date: Mar 2007
Location: Marietta, Ga
Posts: 7,053
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Quote:
Irvin
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Irvin - I wish Facebook would notify me when people delete me so I can 'Like it' |
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#17 |
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Rookie
Join Date: May 2010
Posts: 235
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Sorry but that's complete BS. I've strung plenty of Radicals with no problem whatsoever. I simply mount the frame firmly, make sure it's secure and string the racquet. I've never purposely "stretched" a frame. Obviously, you didn't use the mounting on the KM well.
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#18 | |
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Hall Of Fame
Join Date: Apr 2011
Location: The Desert
Posts: 3,008
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Quote:
10lbs is a lot. I rarely do more than 5 and then only on hybrids where I'm stringing the crosses higher anyway.
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Neos 1000, Eagnas Combo 810 Member USRSA |
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| fortun8son |
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#19 | ||
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Talk Tennis Guru
Join Date: Jul 2007
Location: San Diego, CA
Posts: 29,087
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Quote:
Quote:
It's nothing new and the subject has been raised numerous times. So, please don't act like a know-it-all and state it should never happen or it's an issue with the mounting system or the operator. It DOES happen and I've never noticed it apart from Head frames. The Prestige, Radical and PT 280/630 are infamous for rounding and shortening. Just because you two have never noticed it doesn't mean it doesn't occur. How often do you measure the racquet's length when you finish stringing Head frames, BTW? Last edited by Bud : 08-09-2011 at 10:21 PM. |
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#20 | |
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G.O.A.T.
Join Date: Feb 2004
Location: at the bottom of every hill I come to
Posts: 11,150
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Quote:
And, I also don't randomly add 10 pounds tension to crosses to compensate which screws up a string job just to make the frame look right. Have you ever played with a frame strung with a 10 pound difference between the mains and crosses? That is totally hosed, and IMO, terrible advice. I'm not being a "know-it-all" when I validly criticize that advice. It's terrible advice, it's not solving the original problem, it ruins the feel of a string job, and it results in a terrible end product for whoever was unlucky enough to pay for that string job. Let me ask you, if you took your frame to someone to be strung say at 60 pounds, would you want them to add 10 pounds on the crosses to "striaghten it out"? How do you think a string job at 60 on the mains and 70 on the crosses would play? Hell, even 55 on the mains and 65 on the crosses? Again, I simply cannot believe some of the "advice" that is being handed out. I don't think the issue is a couple of millimeters as much as it is telling someone to 'add 10 pounds' or stretch a frame by applying force to it. And FYI, I've strung plenty of Head frames and never seen any noticeable difference in the head shape after stringing.
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Wilson Steam 99S poly Luxilon 4G 1.25 @ 45 Last edited by Rabbit : 08-10-2011 at 03:47 AM. |
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