Hmmm... as I understand, the foam is placed inside the T joint, not throughout the whole frame, right? I don't think I've ever seen any foam in the frame in any of the broken rackets post mortem photos.
http://bbs.badmintoncn.com/thread-196139-1-1.html not quite sure exactly where they put it since I haven't looked at the whole thread and haven't translated what he says. Doesn't seem to be in the whole frame though. Could still have an impact on frequency though, I think.
If anybody hasn't got an iPhone - I can't be the only one - there's a free program called PitchPerfect that does exactly the same thing on a PC. All you need is a microphone of some kind. Just tested a couple of strings against generated tones, and they sound spot on. Now I've got some kind of objective measure of tension loss, but this means I'm probably going to re-test everything. Thanks, OCD!
Interesting to see how much tension is lost early on... just tested the Adidas Power Tour 66, and it's gone from 1277 Hz to 1228 Hz in 12 hrs before it's even hit a shuttle! 3.8%, IOW. Looking forward to seeing the "fresh" frequency of Zymax 62 at 30x31...
Mark, did you ever get a reading for ZM62 @ 30x31 ? Contribution: ZM65 @ 26x28 on NR700RP using crank machine tension tested with scales immediately before 0hrs = 1189 Hz
Your original post lists these results: So, 100 Hz lost in 3 weeks??!!! Kwun's chart and results suggests approx 26lbs as well, and that's with ZM62 being used. Were they measured on the same make and string pattern of racquet? Just seems too high. I would expect somewhere around 1140 - 1170 freshly strung looking at others' results.
Yes: fresh out of the machine... 1366 Hz. Another one for the pot: Adidas Power Hybrid: [TABLE="width: 204"] [TR] [TD]0[/TD] [TD]1284[/TD] [TD][/TD] [/TR] [TR] [TD]1[/TD] [TD]1274[/TD] [TD]0.78[/TD] [/TR] [TR] [TD]3[/TD] [TD]1263[/TD] [TD]1.64[/TD] [/TR] [TR] [TD]6[/TD] [TD]1257[/TD] [TD]2.10[/TD] [/TR] [TR] [TD]12[/TD] [TD]1249[/TD] [TD]2.73[/TD] [/TR] [TR] [TD]24[/TD] [TD]1241[/TD] [TD]3.35[/TD] [/TR] [TR] [TD]48[/TD] [TD]1234[/TD] [TD]3.89[/TD] [/TR] [TR] [TD]72[/TD] [TD]1230[/TD] [TD]4.21[/TD] [/TR] [TR] [TD]1st session[/TD] [TD]1210[/TD] [TD]5.76 [/TD] [/TR] [/TABLE]
Of those rackets with zm62 @22x23 lbs in my op, they were strung by stringer A. Iirc at 0h they were around 1180 Hz.
The *stabilized* stringbed frequencies I get do match perfectly with kwun's graph on page 1 for a single string of zm62. Note stabilized after a few days, not immediately off the machine. So I'd expect Mark's 31 lbs to stabilize around 1300.
Your power hybrid frequencies are pretty much what I also get. I strung my MXJJS and SW35 at 30 lbs and theyre staying at 1200 after about 3 sessions
Well... [TABLE="width: 142"] [TR] [TD]0[/TD] [TD]1366[/TD] [/TR] [TR] [TD]1[/TD] [TD]1352[/TD] [/TR] [TR] [TD]3[/TD] [TD]1343[/TD] [/TR] [TR] [TD]6[/TD] [TD]1334[/TD] [/TR] [TR] [TD]12[/TD] [TD]1322[/TD] [/TR] [TR] [TD]24[/TD] [TD]1313[/TD] [/TR] [TR] [TD]48[/TD] [TD]BROKE [/TD] [/TR] [/TABLE] Yep - it broke before I even got the chance to play with it. I suspect two things: 1. It was Z62 Mk1 - I was after Mk2, 2. There was a nick in the string - it's happened before, especially with Ashaway. I don't know how or why it lasted two days, though.
Hmm it seems as if powerhybrid has good tension retention up until you play with it. Dropped all the way down to 1170 hz. But then again, when I string ZM70 in the low 30's, I really don't see the tension retention everyone talks about as it seems to drop a lot. I guess it's something you have to live with when you string it over 28 lbs? Makes me want to try thinner strings at lower tensions
Update of my most recent zm62 @ 22x23 lbs: 1212Hz 0h 1180 24h rest 1155 6h play 1145 8h play 1135 10h play
The percentage of tension loss seems to be the constant, so those of us who use 30+ are going to feel 3+ lb more than the low 20's crew feels 2 lb... I really think rougher strings suffer from this sudden drop in play more than smooth ones do, though, and the Mk1 Z70 was pretty rough.
Another one for the pot: NS30 (white) 30x32, Rev. [TABLE="width: 234"] [TR] [TD]hrs[/TD] [TD]pitch (Hz)[/TD] [TD]total % loss[/TD] [/TR] [TR] [TD]0[/TD] [TD]1320[/TD] [TD][/TD] [/TR] [TR] [TD]1[/TD] [TD]1308[/TD] [TD]0.91[/TD] [/TR] [TR] [TD]3[/TD] [TD]1294[/TD] [TD]1.97[/TD] [/TR] [TR] [TD]6[/TD] [TD]1283[/TD] [TD]2.80[/TD] [/TR] [TR] [TD]12[/TD] [TD]1273[/TD] [TD]3.56[/TD] [/TR] [TR] [TD]24[/TD] [TD]1262[/TD] [TD]4.39[/TD] [/TR] [TR] [TD]48[/TD] [TD]1246[/TD] [TD]5.61[/TD] [/TR] [TR] [TD]72[/TD] [TD]N/A[/TD] [TD]N/A[/TD] [/TR] [TR] [TD]1st session[/TD] [TD]1232[/TD] [TD]6.67[/TD] [/TR] [TR] [TD]2nd session[/TD] [TD]1206[/TD] [TD]8.64[/TD] [/TR] [/TABLE] 8.6% loss after two sessions... not brilliant.
