String tension

[Steved]

I have read the article on stringing with interest. Basically it says that the softer you string the racquet the harder you will smash! (within reason of course) It's called the trampoline effect. There is no reference to any studies on this. Can anyone point to any research on this subject because I for one, find it hard to accept! It would be interesting to find out what tension Simon Archer uses in his racquet at he holds the world record at 260kph.

[Jonathan Phillips]

The basic equations are these:

Higher Tension = More Control
Lower Tension = More Power

Strings at low tension stretch more when they contact the shuttlecock, and then quickly snap back to their initial length. This “trampoline effect” (also known as resilience, or rebound) adds power to the shot: it’s sort of like putting a spitball in a rubber band, pulling back, and then releasing it. If the racket is strung at a higher tension, there’s less stretch left in the string to provide trampoline effect.

On the other hand, tighter strings remain flatter, so it’s easier to control the direction of the shuttlecock. Bear in mind these limits, however: excessive string tension leads to frame or string breakage, and too-low tension means a total loss of both control and power.

Source: Ashaway Strings (Ashaway Line & Twine Mfg. Co.)
http://www.ashawayusa.com/pages/BadTip2.html

[sholden]

In my own experience (for what its worth) when my racket has been strung tightly I have more power overhead, but much less control over the shuttle around the net.

[Jonathan Phillips]

Still looking for something scientific...but have found this for the moment. There is a difference of opinion by Pat Davis, but no science to back it up. This is in contrast to the physics behind the trampoline effect.

Here goes...

Looser gives more power:

U.S.Racket Stringers Association Digest

'The 1996-1997 U.S.R.S.A. stringers digest manual points out these "Basic Facts About Frames & Strings."

1. Lower string tensions generate more power (providing string movement does not occur).

2. Higher string tensions generate more ball control (for experienced players)...."

Changes in String Tension Affect Racket Performance.

Article from Badminton USA by vice president of sales and marketing at Ashaway Racket Strings, Steve Crandall.

'Strings at low tension stretch more when they contact the shuttlecock, and then quickly snap back to their initial length. This "trampoline effect" (also known as resilience, or rebound) adds power to the shot'.

Tension Contentions by Crawford Lindsey from Stringer's Assistant, March 1998 a publication of the United States Racquet Stringers Association (Reprinted on the Harvard Badminton Club website).

This is a detailed and quite technical article . 'At medium-high tensions (increasing from 20lb to 25lb) you seem to get less power as you increase tension. However, this might reverse when you get to very high tensions of >30lb'.

Tighter gives more power:

Two references Notes from Randy Yeung summarizing two references which are as follows:

1. Pat Davis in Complete Badminton (1979) summarizes the following argument.

In contrast to tennis it is generally recognized in badminton that lower tensions optimises control while higher tensions provide more power (shuttle velocity).

2. Chea Swee Ming 'Shuttle Velocity and Control in Badminton Strokes'. (Article in British Journal of Physical Education No.12 Winter 1992).

'Ming's study set out to quantify Davis' observations and tended to confirm those observations, but he also concluded that although a higher tension may be prefered for power, a skilled player can adapt to a lower tension and yield similar results after some adjustment.

An interesting note though, that in his study, at string tensions greater than 20 lbs the string bed approaches an unresponsive stage commonly refered to as 'dead tension'.

[MarkAllen]

Just a few points, regrettably mostly anecdotal. Science is a bit thin on the ground here.

I've been playing, administrating & umpiring badminton for some time now. I have also been stringing for over 10 years now & experiment with strings, patterns & tensions as a matter of course.

First, re the assertion that lower tension equals greater power. The only research that addresses this that I've ever seen is concerned with tennis. The effect of a comparatively massive tennis ball travelling at high speed onto the larger bed of a tennis racquet is an obviously different case to what we're talking about. The power shots in badminton are mostly played by a transfer of the player's body weight through a slow-moving object of very low mass. To maximise the power transferred to the shuttlecock, what is required is a very stiff racquet, and a very stiff string bed. Any slackness in the strings absorbs some of the power into the strings & racquet frame. This is why carbon-fibre is the material of choice for racquets, and why string tensions at all levels of the sport are rising all the time.

When you buy a racquet, it's generally strung at about 15lb tension. I string at 20lb as a matter of course as optimal for most players and also giving a measure of durability. At increasing tensions over 20lb you are swapping marginal extra power for vastly lowered durability. Elite players who may not have to care about durability have been stringing at 30lb for years, and some are now using 40lb -- ie more than is normal for a squash racquet!

Finally, as regards the dead feel when playing net shots. This is a trade-off you can't avoid. You just have to learn to stroke the shuttle rather than bouncing it.

Anybody care to talk about strings? Without being slanderous of course.

[Kelvin]

This is the most concise info. I've heard for this issue, and it's great to hear from an umpire, and fellow stringer on the issue. Most players who dont train regularly dont realize, that you have to stroke the shuttle, not let it bounce off your strings in order to obtain "better control"
I wouldn't mind discussion about certain strings, as I will be trying out different badminton strings soon, other than the Yonex line, also any new additional info from a more experienced stringer is definitely welcome.

[stringerengland]

I have played badminton for over 35 years and have been stringing racquets for the past 15 years. I would agree with the comments in general with string tension. Personally I find a tension of 20 lbs is too high for me, I prefer 18lbs. There are are number of points which have not been discussed with regards to stringing. I use a constant tension string machine compared to the normal lockout type. These machines apply a brake when the reference tension has been reached. My tests have proven that depending how fast you wind the handle has a cosiderable affect on the applied tension. This problem does not occur on constent tension machines hence racquets strung on these machines have more consistent tension from one racquet to another.A topic not raised is the calibration accuracy of string machines. They need to be checked aginst a calibrated tension gauge on a regular basis to ensure that the tension head is pulling to the expected force.Both string clamps and the jaws of the tension mechanism likewise need to be cleaned with a suitable solvent on a regular basis to ensure accuracy.
Most strings are coated with a lubricant to aid stringing and this can affect the final tension of the string job if allowed to build up on string clamps and tension head jaws. Also jaws need to be adjusted to avoid slippage of the string, but not too tight to avoid crushing the strings. In servicing racquets over many years I have seen many racquets which have been strung by amateurs who clearly do not know what they are doing. I have seen racquets where the frame is distorted because the string tension is not consistent across the face of the racquet. When the strings were removed, the racquet returned back to its original shape. Choose who strings your racquets carefully. Racquets which are strung at high tensions are under great stress. racquets with cracks in the frame will not survive. Please be careful to avoid hitting your racquets on the floor or colleagues racquets. Remember modern badminton racquets are very light and will suffer if abused.

[Michael Banks]

Can anyone suggest the best string tension to have when balancing power and longevity of strings?

Also - does anyone have advice on the best strings to buy now. I rememeber the old Ashaway XT21 strings, and cat gut!

[BadmintonsBest]

Just to let you know in response to Archer's string tension etc. Here are a few top players, their string make and their string tension if you are interesed at all.



Archer - Flex 21 micro - 24lb
Vaughan - Microlegend XL - 27lb
Emms - Rally 22 Ti - 25lb
Hunt - Micropower - 27lb

These are all Ashaway string makes and can be found at www.ashaway.co.uk if your interested. Notice though that even Archer who has the record smash does not go above 25lb. I feel 22-25lb is about right, i feel above this will not be any good and there will be no ''give'' in the strings.

[MarkAllen]

Just a couple of thoughts on strings to use; I've already stated my position re tensions.

Gut -- forget it! Low durability, low tension, murder to string, heavy, thick. Need I say more?

I've tried most Ashaway & Yonex strings myself at one time or another & can recommend Ashaway MicroLegend and Yonex BG80 or BG68Ti. Availability of BG80 is a problem though.

Strings of Kevlar or Zyex don't seem to be anything special.

If you have a choice, thinner gauge strings should always be preferred. They're lighter and have to offer less aerodynamic drag, both attributes which should lead to greater racquet head speed and/or lower effort.

[stringerengland]

In reply to Mathew Ross. Mathew please see my previous posting on string tensions and stringing machine calibration. One thing you have not considered Mathew is the tension recommended by the manufactures of badminton racquets. The vast majority of racquet manufacturers do not recommended a tension above 22Lbs max. They will not guarantee their racquet at the tension ranges you mention. Have you tried playing with a rcquet strung at a tension of 27Lbs. It will play like a board. There will be no give in the string at all. Unless you are used to this tension you will find it very difficult to serve because there is no feel to the strings, hence no feedback. If you have a clash with another players racquet, kiss the racquet goodbye the frame will explode. Trust me. I've been there and it did happen. Likewise if you hit the racquet on the floor, desperate to get that shot the racquet will go. Dont try to get a replacement from the manufactures, they wont entertain.

My reccommended strings are :

Yonex BG80. Saddly no longer availble.
Ashaway Micropower. Lots of people like this string and it is durable.

[Stevenio]

Where are you from Keith?

[Stevenio]

--apologies for double posting

[stringerengland]

In respone to Steven williams. I live in Wood Green, North London.

[stringerengland]

Mark Allen. From you comments I take it that you string racquets. Your comments on Gut string are not valid. Gut string is made in a number of gauges. In fact some gut string is made in a thinner gauge than Ashaway MicroLegend XL which is 0.69mm. You need to learn how to string gut string correctly. With modern coatings it is not as bad as you are trying to make out. Regarding your comments on tension. Again you are talking out of your hat. Gut holds it tension very well after the initial tension loss. Avoid extremes of temperature and treat the Gut to a mixture of Castor Oil and Methylated spirits to nourish the string.

Calibration of stringing machines. My favourite topic. Most people use tension calibrators manufactured by eagnas and their ilks. These have divisions marked out at 5lbs intervals. These are a waste of space when calibrating a machine for badminton racquets. I use a hanging balance which has 2oz divisions. This scale is accurate to plus or minus one division and I have the scale calibrated once a year against known test weights which are traceable to the weights used by the national Physical Laboratory to ensure the accuracy of my readings. I contend that the vast majority of racquets which have been supposedly strung at tensions above 20 lbs are not. The reference tension of the machine is way out. As for machines with a hand crank, they are a joke. My tests have proven that you get a different tension on the string dependant upon how fast you wind the handle.

[Frodo]

my 2 pence worth ... I have just had my racquet restrung to 24 lbs, from 22 and I do find there is more power but not as much as I initially expected. It also feels better and am happy with the level of control I can generate.

The advantages are mainly that it is easier to deep clear and less effort is required to generate controlled smashes ... less effort implies more control and fewer unforced errors.

I have heard it mentioned by a professional stringer for the champs .. that over 25 does not make much difference, especially at club level.

Also having watched fellow club members play with racquets strung at 25+, I see very few touch shots, but lots of crash bang wallop ;-)

[MarkAllen]

More on stringing with gut.
My opinion of gut is based on long experience of having to string with it to keep some customers of mine (who won't change) happy. I've tried all the brands of gut I can get hold of & currently favour Babolat VS, which, at 0.70mm, is the thinnest I've come across. It also seems to suit my customers as it has some measure of durability as well as the playability they swear by. But .....
Low tension -- I dare not string it at much more than 16lb, it's simply too fragile. I've had it break during stringing more than a few times too, no matter how much care you take with it.
Murder to string -- uncurling, pre-stretching, oiling, varnishing -- who needs it?
Sorry, if it's any good, why is it so little used?

[Frodo]

for all you stringing experts, a question:

are thin strings better, what is the difference ?

[Martin Dew-Hattens]

I am surprised at some of the comments here. I suppose there are some very good articles on the matter but my own experience tells me otherwise.

a) The tighter the string then the harder the smash - but you have to hit the middle of the racket.
b) If the string is slack then you get more control. This is simply because the shuttle spends more time in contact with the string. More contact time means more control.
c) With very tight rackets you should paint some form of emblem on the strings. This will recover a little of the grip to the shuttle as opposed to slippery strings.

I was first explained this by Rudi Hartono and over 20 years of experience I have never found this to be wrong!

Rudi always used to have quite loosly strung rackets.

[MarkAllen]

Martin..... Nice to hear from such a player on this rather dry thread.
But you didn't say what your own preference was. Would you care to share what your racquet/string/tension combination is?

[Martin Dew-Hattens]

I used to string my own rackets at about 25lbs. I think this is about average for many players. This was with a CAB 8 which I still use !!!!!!

The modern rackets begin to moan and creak at this level and probably should not be strung over about 22 lbs if you want them to last.

Of course at 25lbs the strings may only last one match or less so I had to go stringing 6 new rackets every event.

Even if the strings looked ok they could not be trusted for an important match and maybe at a critical shot!!

Also I plastered the yonex emblem on the strings to retain some grip.

Its all very well having control but if you can't get the shuttle on the floor then some Indonesian player is going to have real fun with you stuck up on the back line. You have got to get some umph
into that smash!!!

"String it hard , and hit it hard"

[SJCorbett]

Martin Dew-Hattens.

At last - someone who knows what he's on about!
I started reading these comments with horror until I read yours!

I used to play a lot of tennis and found the softer the strings the more power, the tighter the strings the more control.

You're right - Badminton is absolutely different. The tighter the strings, the more power, the softer the strings, the more control. A shuttle is a lot different from a tennis ball - even if you only look at the weight factors.

Research? Why not use common sense! try it yourself and see! I've tried loads of different tensions over the years (and strings - by the way - you can still get hold of bg-80, and bg-66 - just not in the UK!)

Those of you who normally play at low 20s: try your next re-string at something substantially higher - if your racket can take it. Try at least 25 or 26lbs. once you've got used to the extra rebound power you'll regain your level of control even at the net. Your clears fore and back hand will be easier, and you'll notice how much more powerful you smash is. Notably, you'll obviously have to keep to the sweet spot. I prefer isometric heads now I play at high tensions.

Lastly - the All Englands this year - I didn't know of too many players with less than 30lbs in their rackets.

[coops241180]

hmmm, some intersesting ones here. Scientifically speaking you would expect loose strings to provide more power due to the "trampoline effect" the problem is that this effect is caused by the stretching of the strings not just their movement. This is why this theory works better in tennis since the ball carries more momentum due to it's weight. In order to acheive a similar effect in badminton the string have to be strung to a relatively high tension - from what i've have read, my own experience and word of mounth ths optimal tension range seems to be 23-30. i would imagine that the tighter you string your racquet the harder you have to hit the shuttle to obtain the extra power from the string. the 23-30 range will simply be the varying strengths of the players involved. of course if your going for a control game ur best going for the tightest strings possible. This will reduce the bounce of the strings and lower the difference between the middle of the racquet and the edges.

Hope this helps

Neil

[Frodo]

the tighter you string your rackets the quicker the strings break :-(

you cant have everything

[thgoh]

Out of curiousity, would there be any problem in stringing the racquet with two different tensions? I've heard a stringer suggesting that I should string the mains 0.5 or 1 lbs less than the cross. E.g. if the required tension is 24, the mains would be strung at 23.5 or 23 while the cross is 24. Thanks in advance for your information.