When stringing Ovals versus Isos, are there differences in tensions on the cross and mains. It seems that the crosses are strung at higher tensions by a couple of pounds (according to other posters). But does the shape of the racquet affect the tension difference between the cross and mains. Just wondering.
Seems that u already perfromed a "search". Personally, I think the "difference" in cross vs main is mainly because of the machine u using, rather than the head shape. 2 pt system generally only have support on main, therefore, u might need 1-2 lb more on cross to maintain the final shape. However, 4 or 6 point system already have extra support to "lock" the shape, and extra force on cross might not be necessary. All the above are for "2 pieces / 4 knots" method. If using "1 piece / 2 knots" method, then main and cross will end up with the same lb anyway, since it's still a whole piece. Personally, I think "2 pieces / 4 knots" method is much more suitable for 2-pt, drop weight type of machines.
reply The difference in cross and main tensions is to do with the way rackets are strung, and has nothing to do with the head shape. You will ALWAYS need a 10% difference between the cross and main string tensions (the average tension is taken by Yonex to be 20 lbs, so the most common difference is 2 lbs, but the 10% figure is more reliable). Oval heads are stronger, but unless your racket actually cracks under high tension, or much more likely, under uneven tensions of a poor stringing job, then it doesn't matter whether you have an iso head or oval head. Beware of stringers with six-point machines who tell you that they always do their rackets without the 10% tension differential. Although the racket looks like it's kept its shape after stringing (because it's been fixed in place at six points), there is uneven pressure on the frame, even if you can't see it. A hard off-center shot and crack! there goes your racket. It depends on the racket of course. I used to play with lots of rackets strung 24x24lb and they didn't break because they were 2U. But I've seen a lot of other players with 3U and 4U rackets that broke easily even though they were only a few months old. These were all expensive top range Yonex rackets. Now I always have my rackets strung 23x25lb by a certified stringer.
Re: reply 1. The 10% is actually depend on how u mount ur racket. On my 2-pt machine, if I mount it with a little bit extra force against the pole, then, I just need about 1.5 lb difference for 22*24. It's kinda very hard to draw the line sometimes. If the racket comes out to be a little bit wider or narrower (say, measure in mm), it's fine. In general, I don't think even the professional stringers can eliminate all the possible factors. Therefore, a little bit off from the orginal shape is acceptable. Actually, some expereinced players actually telling me they know some others on purpose to string different rackets to be either a little bit wider or narrower, to gain better performance. Not sure whether that's true or not, and I am not brave enough to ever try. If the difference is way too obvious, say, in several cms, then, cut the string asap. 2. Can't really understand about the 2nd case. If the racket is in shape (after dis-mount), how could there be uneven pressure? Won't the string just pull all to even after a little bit "break in" period?
err It depends on the racket of course. I used to play with lots of rackets strung 24x24lb and they didn't break because they were 2U. But I've seen a lot of other players with 3U and 4U rackets that broke easily even though they were only a few months old. These were all expensive top range Yonex rackets. Now I always have my rackets strung 23x25lb by a certified stringer. I think the above statements are a bit grossly off base. - stringing 24x24 lb will not harm racquet if done correctly. 24lbs is not high tension especially for top end yonex rackets. If i'm wrong, are you saying 20x20, 18x18 would wreck rackets too? - from my memory, all top end yonex 3U and 4U rackets are somewhat head heavy varieties - meaning the rackets are light overall but not the frame. Top end 3U and 4U rackets with heavy head will be just as strong as a regular 2U racket head of equivalent price range. Look at AT500/700, it has higher recommended tension than 2U OVALs. (except cab22/20 power). Therefore, you can't blame racket failure on the 24x24lbs method. By your reasoning and referencing to one brand(constant), are you saying a low end 2U frame yonex racket is stronger than a 3U mp100/99 or AT/700/500?? Hmm, i should like to see the shape of a low end 2U strung to 28+ lbs. - certified stringer is trained for tennis and squash racket stringing. I wouldn't place much importance of certification when it come to badminton stringing.
Beware of stringers with six-point machines who tell you that they always do their rackets without the 10% tension differential I havent seen any scientific data supporting the 10% is the magic differential tension. Why not 5% or 15% or 20%?? I'm not saying 10% is bad but it is commonly used because 99.99% stringers out there string racket the same robotic way without asking why 10%.
Cooler, I agree have always strung my racquets at 24x24, other racquets at 18x18, 20x20 and 21x21 depend on age and materials, only strung one racquet greater than 24, that was a 28x28, see no problems over the years. Had Swingpower 900 and Ti10 for a long time, and always strung 24x24. Regards Stuart
reply Cooler - I'm only talking from personal experience of what I've seen. I have a 2U Ti-10 that's been strung up to 26x26lb without any problems, usually at 24x24lb, I used it until the string broke from wearing out. I've had that racket for over four years and it's still fine. Whereas I've seen friends with 3U and 4U rackets (SwingPower SA) strung by the same stringer that broke very easily. One guy broke his frame only 2 weeks after buying it from a Yonex dealer. Another guy bought four SwingPowers at the same time I bought my Ti-10, and he broke the last one over a year ago. As for the 10% difference, it's determined by the fact that you have 22 main and 22 cross strings on a racket. You can't arbitrarily change the number. When you've strung the mains, the strings are dead straight and the only tension comes from the frame. When you then string the cross strings, these cross strings distort each main string into a slight zig-zag path, thereby increasing the tension on each main string. The percentage by which 22 cross strings will increase the tension of the main strings is about 10%. Therefore, when you string 22lb main, and then 24 cross, you end up with a balanced racket which as an actual tension of 24x24lb, because the 22lb main strings have been increased to 24 by the cross strings. And this racket has a balanced frame with less overall torque on it.
reply Lazybuddy - the friction between the strings will keep the head shape constant. The friction will vary between between different types of strings of course, but most strings will keep the head shape the same when it's been mounted on a six point machine. You can experiment by stringing the same racket 22x24lbs, 24x24lbs and even 24x22lbs. When you take it off and play with it, the racket head keeps its shape, but the racket feels totally different. With the reversed 24x22lbs, it's useless, you can't play with it at all. Also, if you've ever hand-strung a racket (that is, without any supports or mounts) you'll have seen that, even at low tensions, a racket head is very flexible and will distort huge amounts depending on the tension. Most people feel their rackets unstrung and think of their rackets as being very stiff, but at 20lbs or over, the graphite bends like soft plastic, which is why it's important to have a balanced tension. I've seen a racket head made into a perfect circle before snapping at the 3 and 9 o'clock positions and others rackets stretched into long ovals before snapping at the 12 o'clock position. You can't underestimate the stress strings put on frames. On the point about certified stringers, surely Yonex certified stringers will have relevant knowledge about badminton rackets. I can't believe Yonex would certify stringers who didn't know something badminton. My regular stringer is certified by a tennis association, but he spends most of his time doing badminton rackets and I think he does a great job.
reply Aren't there any Yonex certified stringers on this forum? Or any professional stringers? I'd like to hear what they have to say about this. The stringer I use is quite well-known in London. He used to do Pete Sampras' tennis rackets for Wimbledon and does badminton rackets for some English and Danish national team players when they're here for championships. I don't think he has a Yonex certification (though he does have a photo of himself with Mr YoneYama). He's about 55 years old and has been a stringer all his life so anything he tells me about stringing I will take as the bible.
well, i have seen result from stringers who have done stringing for yonex tournaments (i don't know if they were yonex certified) and i can borrow a quote from shania twain ' that don't impressed me much'. They still string rackets one way for all type of tensions and racket heads. About your 55 year old friend. What he learned decades ago maybe be out of date. Today technologies have change from wood, guts, grommetless to graphite, vectran, nylon, titanium, mp bumps, etc. Passed over techniques never been questioned nor refined. It still works but it may NOT be the best technique for today equips. for an analogy: kung fu had been around for centuries through handover from generation to generation. Then a young lad name bruce lee comes along and refined the techniques, junking some of the old kung fu strokes as useless, invented some new ones as well as adopting some techniques from west. How can bruce lee be the best if he is better than the instructors that taught him eventually? Same logic applies to professional anything.
Re: reply The customer is always right. Unless otherwise specified, the stringer reserves the right to string to the requested tension using the method of the stringer's discretion. If the customer chooses to request a different tension between main and cross, then the stringer should honor the customer's request. A common misconception about the 6 point suspension method is that it will prevent the racquet head from distortion after stringing. The 6 point suspension will only hold the shape of the racquet for the duration that the racquet is on the machine. The suspension system will ensure extra support when pulling to reduce stress and distortion on the racquet head during the pull. At the completion of the string job, when the racquet is removed, the head shape will equalize based on the tensions put on it by all the strings - mains and cross.
Another guy bought four SwingPowers at the same time I bought my Ti-10, and he broke the last one over a year ago. just curious, were those 4 swingpowers SP version?
reply Badminton stringer to kung fu master? A bit of a stretch, even as an analogy and if you knew what my stringer looked like (old, bald, fat) you'd laugh too. I know stringing is a craftsman's skill but not the kind of thing that takes a lifetime to master. More like driving a car - it takes you a few weeks or months to learn it and get good at it, but a lifetime of experience makes you safer and more competent. The SwingPowers were all bought in London and had UK serial numbers. Why, are SP rackets especially fragile?
Re: reply Sigh. Just because someone does an unique routine for decades doesnt make him a master of it - his scope of knowledge would still be limited. Take your car driving skill example, if you learned and drove an automatic honda civic coupe in your hometown for 50 years, you might think you a guru master in driving skill - SO WRONG. If given different parameters and environment, you would not be proficient at all. Some variables are: - manual shifting - rear wheel drive vehicle - a larger vehicle - a truck, 4x2, 4x4, awd, with/without limited slip - a semi pulling a trailer - driving in bombay or shanghai - driving in bonn, or route 66 in usa - driving in uk/aus/nz where the lanes are reversed. - etc I bet you that anyone who had driven in condition of above (less than 50 years) would out drive you (with 50 years driving experience) if you're put in their situation/environment. Same goes for a stringer. He/she string racket the same way using same machine for 50 years, he/she is just average or above average, definitely not a master.
