I agree. The "1 lb" difference is referring to the "min and max" recommend tension between different models with different "U". The "2 lb" difference that we are talking about, is the "main vs cross" for the same racket.
Hi Taneepak and LazyBuddy, You guys misunderstood me. There is a 1 pound difference between 3U and 4U rackets. But for old models, they also recommend two tensions for main and cross: For Ti 10: 3U縦17〜20ã€æ¨ª19〜22 2U縦18〜21ã€æ¨ª20〜23 For NS7000: 3U：19〜24 2U：20〜25 So for the older models, they recommended different tensions for main and cross, but this is no longer the case for the latest models... Regards, CB
There is no inconsistency. One is a brief classification of tension range, usually used in circumstances where space is limited, like on the cone of a racquet. The more detail tension range is usually indicated in Yonex's spec chart. For example, on my MP99 2U the small label on the cone of my racquet says 18-22lbs, 8-10kg, but the spec chart says Main 18-20lbs 8-9kg, Cross 20-22lbs 9-10kg. Despite its modest tension range of 18-22lbs, I string my MP99 to 27-29.5lbs.
It might depend on your source. I have the UK Yonex badminton catalog 2005 and it says NS7000 3U Main 19-22 lbs Cross 21-24 lbs NS8000 3U Main 19-22 lbs Cross 21-24 lbs AT800OF 4U Main 19-22 lbs Cross 21-24 lbs AT800DE 4U Main 19-22 lbs Cross 21-24 lbs AT500 3U Main 20-23 lbs Cross 22-25 lbs AT300 3U Main 20-23 lbs Cross 22-25 lbs MP99 3U Main 17-20 lbs Cross 19-22 lbs MP88 4U Main 16-19 lbs Cross 18-21 lbs
at first when i read this, it kinda made sense, but come to think of it, if you were to pull a rope with 200lb of strength in opposite directions as opposed to pulling the two ends with only 100lb of strength in opposite directions, the rope isn't going to stretch a whole lot more, because it is not very stretchy just my analogy.. dunno if it can apply to badminton strings
It all actually depends.. guess what.. 2 days ago i tried tensioning the other way round Main 28 Cross 26lbs.
what i meant was i dont think badminton strings are THAT elastic, far enough that tension increase will be directly proportional to length increase, if you know what i mean... so even if the string is stretched for less than 1mm, 1lb of tension increase isn't impossible (im not saying that <1mm is going to give 1lb of extra tension, just saying its not impossible)
isn't that what elastic means? real example with BG66 I took a length of BG66 and hung 24lb of weight on it and measured the increase in length. 2570mm stretched to 2795mm so a 240mm centre main would stretch to 261mm under 24lb tension so how much extra tension do you think you'll get by stretching it another 0.6mm? <edit> umm, 0.5lb+ bit less than 0.6mm using BG66 though. different strings would react differently though. The stiffer the string, the bigger the difference. So I would expect a smaller tension change with BG65 than BG66 because it is more stretchy
oh.. i didn't know string stetches that much under tension (im no stringer ) but thanks for all the measuring 2570mm (0lb) => 2795mm (24lb), so 240mm (0lb) => 261mm (24lb), so each extra pound should increase the total length by 0.875mm, so 0.6mm would make the tension go up about 0.69 pound... also, the BG 66 is probably one of the more stretchy strings, considering its only 0.66mm thick. if say BG 65 stretches less, then 0.6mm can easily equate to 1lb edit: oh is BG 65 more stretchy? then im not sure.. maybe you should measure the BG 65 lengths for us too.. that would be great thx
BG66 0.81%/kg BG70Pro 0.92%/kg BG65 1.17%/kg BG80 1.23%/kg BG68Ti 1.33%/kg the values are (change in length) / (original length) per Kilogram tension the 66 and 70pro where done quite a while ago, and I don't have any more lying around. The 65, 80 and 68Ti were done today It would be nice if someone else would have a go and see if they get anything similar.
wow thanks for measuring out all those strings!! i think it would be helpful if an experiment were conducted here at BC regarding string tension loss over say.. 1 month's time. i'll post about it (possibly in a new thread) tomorrow if im not busy meanwhile, anybody else able to try this measuring thing would be helpful cheers
http://www.badmintoncentral.com/forums/showthread.php?p=229247#post229247 as promised i hope my experiment makes sense tho
a question i've thought of If stringing at 2 lbs difference , won't the course of the shuttle differ when the shuttle hit the area where there's crosses and mains due to the fact that the amount that the string would be able to stretch differs from the different tension ?
what we're trying to say is that the 2 extra pounds are mostly made up when u string the crosses on. you would normally avoid hitting the shuttle near the edge (where there is only 1 type of string) because it isn't going to give you power (too far from sweetspot), so that should normally not be too big of a worry. hope this helps
27 lbs X 27 lbs on a MP-100 Last night I bumped into an unregistered BF lurker at VRC. He showed me his MP-100 that was outwardly round cross wise. It was initially strung at 27 lbs X 27 lbs and its shape was all right. I guess after a couple of hard sessions the cross strings relaxed more than the main strings. So, a safe bet is still to add 2 extra pounds on the cross to keep shape of the racquet. Just my two cents.
It may depend on how it was strung. Maybe it was done on a 2 point machine. My machine has side supports. I have been stringing my own racquets with the cross at lower tension than the mains since Jan 2005 and have had no problems. Mostly at 22x20, but i have had my Ti-10 and MP100 at 26x24 and 26x25 and not seen any problems with the head shape.
