To get closest to how the tension feels to play with, shouldn't the standard be the average of the tensions used? A 25/27 stringbed will feel tighter than a 25/25. A 23/25 will feel looser than a 25/25. Shouldn't 25/27 therefore be classified as 26. Shouldn't 23/25 therefore be classified as 24? Here we are, united in our desire for a universal standard, but divided on what that standard should be.
This is a tough question to answer. Even the definition itself is not very well defined. What tension are we talking about? tension of the string? or tension as pulled by the machine? Tension of the string: There are a lot of variables and external factors. First, friction is everywhere. the grommet, the main string can reduce tension by a fair amount. We measured before that once we pulled a string via a grommet, 5+lbs is loss. Even worse is cross strings, each main string contact result in tension loss. Furthermore, even if we pull the main string at say, 20lbs, after we weave and tension the cross string, the main string has been stretched (from straight to zig-zag), and as we know that will increase tension of the main string. So to get to the true tension of the string itself, it is not that easy! Tension as pulled: you can probably do that, and most of the time, that's what we are doing as we are just reading off the tensioner setting, but that's not close to reality. After pondering about that, then we can start thinking about main vs cross string tension.
I don't think 24/26 would average out to 25/25, and here's why: as crosses are pulled, the mains go from being straight to being "zigzagged" because they have to run over and under the crosses. Thus, the mains tension increases but, assuming the crosses are massaged to get rid of friction, the cross tension will not. "24/26" would then end up more like 26/26. Back when I used to string I would interpret "give me x pounds" as x on the crosses and or x - 2 for the mains.
That is exactly the problem. We use the tension pulled by the machine simply because it's the easiest value to understand, control and to setup. A really comparable value, almost independent from machine types, tension ratios and even string thickness would be to measure the stringbed stiffness. I've discussed that with @Alex82 a while ago, and this is fairly common in tennis but it seems to be a bit more difficult to get proper results with badminton rackets. The downside is, that you need to spend some serious money to get the needed measuring equipment - like this one: https://www.stringway-stringing-mac...-stringlab-2-stringbed-test-badminton-tennis/ Even if you have the machine, you need to first of all figure out for yourself the right relation between machine settings and the resulting stringbed stiffness - not even mentioning having to teach your clients what stringbed stiffness is. It's the same with racket specs, where it is far easier to measure and understand the balance point compared to the swing weight - even if the swing weight is hands down the far more telling value. So even there was some standard in terms of tension ratios, the result on the racket would still vary a lot due to the different tensioners, pre-stretch and pre-weave preferences, knot quality etc. etc., so there is no reason to even define a standard.
Agree, the stiffness part is what you feel as tension. It also differs per string. A friend of mine has this apparatus, it's useful sometimes, but you have to know how to translate it back to a stringing recipe for it to help you nail the goal (target hardness = support stiffness + racket variations + string hardness + tension mechanism + stringer consistency). To answer the original question; the +2lbs (or 10% according to Yonex) is also not ideal. If we assume the racket shape unstrung is the ideal shape, for the racket to perform its best, +10% makes for a really egg-shaped racket. For us, 25x25 with 6 o'clock adjustment after putting tension on first main (when it is only tensioned through the top grommets, not bottom), or alternatively +10% for bottom half crosses and +0% for top half reached the closest results to the original shape. This also resulted (in our opinion) in the more 'alive' stringbed. Read more about our experiment in racket head shape retention, can be found here: https://badmintoncentral.com/forums...nging-through-science-fun-with-charts.188282/
But if you would actually string 26/26, wouldn't the same thing happen as well? So 24/26 feels like 26/26? but 26/26 wouldn't feel like 26/26? It becomes pretty arbitrary and up to personal interpretation what each should feel like on a racket. (although it could be why some of the players I string for tell me that my 'x' lbs is tighter than their previous stringer's 'x' lbs, since I string square tensions). And how do we know how much of a difference the zigzagging makes? I have a hard time imagining it to be 2 full pounds.
A reason for a standard is to make a window of results for clients who change stringers as small as possible. You discuss how close or not close a standard would come, which is IMO a nerd topic and not the problem which clients and customers face. IMO it should be clear that the standard should be defined under constant pull and with fixed clamps. A standard can't count in any failure or sloppy craftmanship. So IMO there is no point to discuss how close anybody clamp or how bad a knot is. The aim is to have the smallest possible window of results under the claim that any stringer do a mediocre to reasonable job. If I were a client of myself and request 26lbs, I would get 25/26. If I go to @s_mair or @Mark A or @kakinami or @DinkAlot I guess I will get a 26/26 job. If I would go to @j4ckie who argue with physics and talks about a real real 26lbs job I would maybe get 27/29 or 26/28, right? If I go to @DarthHowie I would get a 26/28.6 job? IMO there is nothing wrong when I hand out a 26lbs request as 25/26 and it would be also as a player okay for me to get 26/26 or 24/26 or even 23.5/26. All stringbed would playable and enjoyable for my strength and would not harm my game. If I get tighter jobs than my prefered string tension I would not be okay with and it will affect my game in a bad manner due slightly more mishits, less poweful smashs and maybe pain in arm and shoulder, short length under pressure. From my perspective a standard should be something which aim the benefits for customers and clients and which is also done by most stringers who also don't know this standard than fighting if it is 26lbs right off the machine, if any string segment has 26lbs, if the customer have 26lbs on string bed when he hits the first time and so on. Focus on the client and keep the window of results so small as possible.
Why makes life so much difficult even if you are pro player. Just string your racket with your regular number (whatever it mean). Then adjust it +1 or -1 for each restring. It just takes 3-5 times at most to get your best fit tension for your preference.
I don't know about feel, but 26/26 set might end up as 26/28 result. That can be calculated fairly easily - each main moves up, then down, by half the thickness of the string (the cross moving the other half). Compare the straight line with the zig-zagged line.
You would have got 25/26 from me - I always took single-number tensions to be the cross tension, then knocked off one pound for the mains up to 30, and two pounds for mains over 30. (My personal jobs were 33/34 because that's what came out of the machine easiest.)
So it changed. Different machine? I had this post in my mind: https://www.badmintoncentral.com/fo...-and-recommended-tension.173089/#post-2577286
I think the standard should be whatever the stringer does is your standard. If you want consistency you use same stringer, same machine. Then you tweak your tension from there. If you string at a shop with different stringers, you should pick a stringer and stay with that stringer, unless you can compare string jobs it is hard to compensate to equal the other stringer. When I did ATP and WTA tournaments we tested on each machine and used an ERT tennis computer. We try to keep each pro with same stringer and same machine but sometimes emergencies come up and someone has to fill in for someone else. Knowing our ERT numbers on each machine we can compensate if we need to switch stringers. My friend usually has a higher ERT number than me, it has happened before, I was doing a racket and a player needed asap, so we had to switch stringers and machines, knowing our ERT numbers we can compensate to try and equal each other. If you want a standard use the same stringer and make sure he uses the same machine. Most people are not going to equal each other and I am sure most stringers are using different machines, so your standard is not going to equal mine even if we are doing same tension, same machine, same string pattern, same string, we live in different countries so my humidity is going to differ from yours and that is also going to effect strings. Who ever is stringing for you is the pro (meaning profession, because he is probably getting money from you, = Profession, Professional) so who ever the stringer is makes up his own standard. If you don't like it, find another stringer. I think I have had plenty of satisfied customers, but I am sure I have had a few who think I am garbage. If you don't like my work you are free to dind another stringer, and people are free to come and use my stringing abilities. Who ever is stringing on a machine, he/she/they are the king of their own castle. They make their own rules. If it ain't broke then don't fix it. If your happy and you know it clap your hands. The standard is your standard. Smell what the Rock is cookin? Sent from my LG-US998 using Tapatalk
Yes - one machine needed a bit more differential to get the rackets out with the minimum 12/6 distortion.
