If you’ve been playing badminton for a while, then you’ve likely heard players talking about what string tensions they use on all of their rackets. Some may use 20 pounds (9.1 kg) and others may use something even past 30 pounds (13.6 kg)! But which one is best for you? We’ll dive into this question in this post and answer what, and perhaps more importantly, why a particular tension is best for you. We won’t be talking much about different strings themselves, but you can find all of our comprehensive guides on strings (and more!) in our Badminton Equipment page.
Beginner badminton players should use a string tension between 18 and 22 lbs (8.2 and 10 kg). Intermediate badminton players should use a string tension between 22 and 26 lbs (10 and 11.8 kg). Advanced and professional players should use a string tension higher than 25 pounds (11.3 kg) or whatever they feel most comfortable with. Note that using a string tension that is outside the range of a racket’s recommended string tension – which advanced and professional players often do – will void the manufacturer’s warranty, so do so at your own risk.
What is String Tension?
String tension in badminton is a measure of how much force is used to stretch the strings across the racket. The higher the force, the tighter the strings are. You can think of tension as the opposite of compression – which, in contrast, is the measure of force when pushing something inwards rather than outwards.
String tension is typically measured in pounds (lbs) or kilograms (kg). As noted above, badminton rackets are usually strung between 18 and 27 lbs (8.2 and 12.2 kg), with beginners preferring their strings to be less tight and advanced players preferring them to be more tight. To understand why, read the sections below.
Some of you may think it strange to use pounds or kilograms to measure string tension since those measurements are typically used to measure weight, not force! However, they can actually be used to measure force, as you can see in these 2 Wikipedia articles: Pound (force) and Kilogram-force. Simply imagine a string hanging from a ceiling with a weight attached to the end of it. The amount of force the string experiences due to the weight is the string tension.
If you’re curious, you can convert between pounds (lb), kilograms (kg) and Newtons (N, the International System of Units’ measure of force) by following these conversion rates: 1 kg = 2.205 lb = 9.8 N, 1 lb = 4.444 N.
Why is String Tension Important in Badminton?
String tension is important for all badminton players to consider because it affects many aspects of your game play, equipment, and even health. Let’s take a look at them more closely:
- Sweet Spot – The sweet spot is the area where you can generate the most power on your racket. Lower string tension creates a larger sweet spot while higher string tension creates a smaller sweet spot.
- String Durability – The higher the tension in your string, the less durable it is. This is because a higher tension increases friction among the strings when they move as the pressure against the strings is higher. Moreover, since higher tensions create smaller sweet spots, it makes it much easier to mishit. Mishits increase the chance of breaking strings because areas outside the sweet spot cannot stretch as much which makes it easier to snap. This is especially true near the racket frame.
- Power – In general, lower string tension increases power while higher string tension decreases power, according to a study on The Effect of String Tension on Shuttlecock Velocity done at Mahidol University. This is because lower string tension allows the string to bend inwards more, making it easier to create a trampoline effect, and therefore more power.
- Control – Lower string tension decreases control. Since lower string tension allows the string to bend inwards more, the contact time is increased (also known as dwell time) and the shuttlecock is affected by the racket’s rotation more. This makes it so you have less refined control over the shuttlecock, making it easier for the shuttlecock to deviate from the desired path.
- Energy – According to a study done at the University of Wyoming, expert level badminton players are able to produce shots of similar quality with rackets of different string tensions. However, these experts prefer higher string tensions because they are able to save more energy in their strokes as lower string tensions require them to “alter their striking motion and increase the flexion of [their] wrist and fingers during impact”. Note that this study was only done on expert badminton players and does not apply to beginner or recreational players.
- Injuries – Playing with too high of a string tension for your level will make you more prone to injuries. Since it is more difficult to get power with higher string tension (as noted above), players who use string tension that is higher than what their skill level can handle may try to add additional power by straining their arms and elbows in a way that compromises their form. Bad form combined with added strain is a recipe for an injury, especially with repetition. So make sure you go up in string tension gradually and stay within an appropriate tension range where you do not need to compromise form to get the desired power. And make sure to read our post on the 5 Most Common Badminton Injuries and How to Prevent Them – it can save you from a lot of pain and prevention is always better than having to go through treatment.
For more information, check out Yumo’s post about How to choose a Badminton String and String Tension. Yumo is a store in Richmond, Canada that specializes in badminton and ships products to many places around the world. They have their own blog and YouTube channel where they teach badminton enthusiasts about the various products that are available.
Why is the Recommended String Tension Different for Each Skill Level?
The recommended string tension is based off of skill level because the properties, as noted above, change as tension changes and each skill group gets the most benefits from the recommended string tensions. Let’s go over why in each group:
Beginners (17 – 21 lbs, 7.7 – 9.5 kg)
Beginners are recommended to use a low string tension because it creates a large sweet spot and helps generate power more easily. A large sweet spot is especially beneficial for beginners because beginners have not had much practice in hitting the shuttlecock at a precise location on the racket. It takes lots of practice to be able to consistently hit in the same spot, so having a large sweet spot gives a needed margin of error for beginners. Furthermore, beginners tend to have trouble producing power in their shots because it takes time to develop the correct form and swing to produce power easily. The lower tension helps to produce power more easily and gives beginners an extra boost.
Intermediate (22 – 26 lbs, 10 – 11.8 kg)
Intermediate players are expected to have their basic form down and to be able to perform all of the basic badminton shots. As an intermediate player, power and sweet spot size is less of an issue but control becomes more important. Hitting the shuttlecock an inch or two higher or further can make a big difference so control becomes a higher priority. However, we don’t recommend intermediate players to go past 26 lbs (11.8 kg) because most are not strong enough to maintain power past this point and performance may actually become worse.
Advanced and Professionals (25+ lbs, 11.3+ kg)
Advanced and professional players probably already know what they are doing at this point, so they know what tension they feel most comfortable with already. As a general guideline, we suggest a string tension of at least 25 lbs (11.3 kg) because advanced players don’t have problems with small sweet spots, require extremely precise control, and are still able to generate a similar amount of power even with high tensions. Also, as mentioned earlier, a study done at the University of Wyoming has shown that advanced players can actually save energy from higher string tensions.
While our recommendation is at least 25 lbs (11.3 kg), most top badminton players actually use string tensions ranging from 29 to 35 lbs (13.1 to 15.9 kg)! These players have trained all their lives so they know how to fully utilize the high string tension while retaining a lot of power. Don’t try this string tension unless you really know what you’re doing!
Does My Racket Affect Which String Tension I Should Use?
Each racket has different recommended string tension ranges (which can also be based on your racket’s weight, which you can read about in any of our racket guides) so you should be aware of what yours is when getting your racket strung. You can find this information pretty easily online with a quick search, on the company’s catalog, and usually on the racket itself. For the most part, it shouldn’t be an issue unless you are stringing at a really high tension that is past the racket’s recommended tension range – in which case your warranty will be voided.
How Long Does String Tension Last?
String tension decreases over time, especially with usage as the strings get stretched. Within the first 24 hours of a racket being strung, the tension can decrease by 10%. In a month, string tension can drop by up to 20% but usually does not drop much further.
If you want to find out your string tension, there are devices that can help you do that, like the Tourna String Meter String Tension Tester. Another method is to use the Stringster App app that attempts to measure the frequency of the strings as you tap on them since string frequency changes as the tension on it changes. You can see a demo of it over here:
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