12 March 2020

We try the plucky apps that test your racket tension!

Did you know that you can use your smartphone to check your string tension? When during our tournament trip to the Rafa Nadal Academy one of our players started hitting his racket strings with a butter knife we wondered what was going on... The answer turned out to be much more interesting than we had expected.

Over the fresh fruit, yoghurt, nuts, coffee and eggs (and much besides) that you get for breakfast at the Rafa Nadal Academy by Movistar, Adam was testing his strings. He was hitting the strings with a knife, and seeing what number registered on his mobile phone.


TennisTension iphone ($6.99), android (£7.99) Claims to be "the first working mobile app that instantly measures the momentous string tension with extreme consistency and accuracy (the error is less than 0.2 kg)... analyses the ringing sound heard from the strings when they are hit anywhere with any stiff object (pen, pencil, another racquet, fingernails, etc.)"

RaquetTune iphone ($2.99), android (£1.40) Claims to be "simple and straightforward to use, the app uses the sound generated by tapping the strings to calculate the tension with high accuracy. In addition, the interactive swingweight calculator aids in customising your racquet to fit your own stroke pattern, while the stiffness calculator allows you to simulate different racquet configurations."

He said was using an app called RacquetTune but said Brian, another Local Tennis League player, he knew about a much better app - TennisTension. So we went in search of Brian, who plays in the Kennington & Brockwells Parks League in London, to see what the story was. Here's his story:

When I first came to the Rafa Nadal Academy in 2017 I played so much tennis, by the end of the week, by elbow was nearly falling off. It was so bad, I thought I might have to give up tennis. I knew it wasn’t my racket because it’s the most arm-friendly racket you can get. My technique is ok too so the only other thing it could be was the strings.  

Turned out, the tennis elbow was a result of playing with the string the pros use – they all play with polyester because they give you a ludicrous amount of top spin. Roger Federer uses gut strings going one way, and Alu Power (polyester strings) going the other way, and I thought if it’s good enough for Roger, it’s good enough for me and for 3 or 4 matches it was. It wasn't.

Polyester strings lose tension very quickly so the pros change their rackets every six games. What the amateur player doesn’t realise is that when the strings lose tension, that shreds your elbow. But I wanted polyester strings because the top spin is so great. So what was the solution?

I tried a whole range of different polyester strings, re-stringing my racket every time, but at £30 a go, it got very expensive. Eventually, I decided to buy my own stringing machine so I could mess around with different string and see what worked. I got totally obsessed!

I found some German strings called Weiss Cannon. They gave plenty of top spin and didn’t shred my elbow but I needed to know if the tension I had set the strings was the tension I was actually getting because different strings and different tensions totally change the feel of the racket.

This is where the app came in. I went on YouTube and found that with the app, you tap the strings and it makes a noise and by the pitch and tone of the sound, you can work out the tension of your strings.

When you use a stringing machine you use grippers to grip the strings to hold the tension and if it slips a little, you lose tension and that was my problem. I had not set the gripper correctly. I knew I had to adjust the grippers to the point where I was getting tension I wanted for my racket and now I am happy. 


It must have worked because Brian was one of the tournament winners!

Brian's Guide to stringing

Brian uses a full bed (ie the same strings going in each direction) of Weiss Cannon strings. He strings at 22kg which he says is low, but they will last for 10 matches and he re-strings his racket before every game.

If the weather is hotter, as it is in Mallorca, the balls fly faster through the air, which means you want to the strings to be tighter.

Think of strings like a trampoline: the looser they are, the more power you have, but the less control. The tighter they are, the less power there will be, but the control is greater.

You can set a different number of strings in each direction which will give different results. For example, 16 by 19 will give you more top spin whereas 18 by 20 will give you more control