Inertia X1

Accurately measure your racket's swingweight

Swingweight is the parameter that more than any other determines how a racquet swings and hits the ball

With Inertia X1, you can measure it quickly, accurately, and repeatably

Inertia X1 is the Italian instrument for measuring the swingweight of a tennis racket, with a dedicated app for iOS and Android. Designed for passionate tennis players, stringers, and specialty shops who want to measure, compare, and customize their frames with professional precision.

Discover Inertia X1
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“Roger is incredibly sensitive, he can feel a difference of just 1-2 points in swingweight.

When we moved to the bigger frame, the job was to balance the mass in the head to give him that extra push on the backhand without losing the speed of execution that distinguishes him.”

Ron Yu, Roger Federer's historic stringer
Fast and accurate swingweight measurement

Main features:

  • Fast and accurate swingweight measurement
  • Essential for matching and customizing rackets
  • Job archive
Targeted at tennis shops and stringers

Who is it dedicated to:

  • Tennis shop and stringers

Offer a professional matching and customization service.

  • Passionate tennis players like us

To deeply understand how our racket works

Try Inertia Racket Tuner, the professional software for customizing and matching tennis rackets.

Calculate weight distribution to the millimeter and customize your frame.

Free, online and without registration

Go to the Inertia RT page

Client Reviews

For those who love having everything under control

Over the years I have come to realise how important details are in tennis: in technique, tactics, physical preparation and nutrition, but also in equipment.

I consider it essential to be aware of the equipment you are using. Knowing the weight and balance of your racket is definitely the first step, but it is not enough: in fact, for identical values, the swingweight can vary significantly and can also deviate quite a bit from the one declared by the manufacturer.

Being able to measure it precisely becomes even more important when you want to customise the racquet, to make it more suited and performant in relation to your own game, or when you want to match multiple frames to achieve as uniform characteristics as possible.

The programme is also very useful for this purpose Inertia Racket Tuner, which allows for precise work on the customisation and alignment of frames.

For those who love having everything under control, perhaps already own a stringing machine and dabble in weights, balances and measurements, this is a tool that cannot be missing.

Tommaso

Tennis enthusiast, former 3.1 - Padua

I was really impressed!

Hi Paolo, amidst a thousand commitments I've only managed to use this tool now, but I must say I'm really impressed!
I own 8 rackets and before buying this device I had the balance of 6 of my rackets checked by my trusted professional stringer using his electronic machine, a tool that costs a couple of thousand euros, and your device gave the exact same results!
I thoroughly recommend it! 👍👍

Eoin Gleeson

Amateur tennis player, Ireland

Exceptional value for money

I am getting more and more seriously into the magical world of racquet stringing and customisation, I believe it is important to know and keep track of the modifications I make, and the Inertia X1 tool that I recently purchased seems to fit the bill. My experience with this tool and the supplied software was very intuitive; once the initial wizard procedures were completed, I was able to be ready for my first measurements in just a few minutes. The app is well-made and simple to use, plus the tutorials on the website are a valuable help. I believe an outstanding job has been done by the developers and that the equipment has exceptional value for money.

Matteo Compri

ERSA Stringer, Bovolone, Verona

Essential for every stringer

The Inertia X1, the fruit of great passion, dedication and expertise, proves to be a truly indispensable tool for every stringer and all industry professionals.
The after-sales service is also excellent: availability, professionalism and attention to the customer's needs translate into prompt, high-quality support.

Daniele

Stringer, Emilia Romagna

Extremely satisfied, exactly what I was looking for

Finally with Inertia X1 I have found a way to get precise and reliable numerical feedback for the many customisation tests on my rackets, without having to invest a fortune in professional tools, which is out of the question for amateur use like mine. Warning: despite the affordable price, the precision of the instrument is incredible and by no means inferior to that of other tools. Last but not least, Paolo is a very knowledgeable and helpful person; I had the chance to have long chats with him on technical aspects not even directly related to the tool and he was able to explain physical concepts, which were very complex for me, in a clear and simple way.

Highly recommended

Dario Belperio

Amateur tennis player, Naples

Accurate and reliable

An excellent tool for both professionals and tech enthusiasts. Small, reliable, precise and affordable.

Essential for knowing the swingweight of your equipment, knowing what you are playing with, and eventually matching two or more rackets.

Racquet Passion

FITP Equipment Technician, Tivoli (Rome)

Red circle!

I am satisfied with the tool, so simple to use and paired with effective software.
An even better aftermarket service.
Undoubtedly a positive 5-star review with a red circle around it

Suwatchai Woonkon

Tennis coach, Brussels

Top

Before discovering Inertia X1 I used the traditional formula to calculate inertia based on the standard coefficient, weight and balance.

The result was obviously very, very rough due to the weight distribution along the racket.

Now I'm going straight for a sure thing and the Inertia X1 is super comfortable to take straight onto the pitch.

Paolo is always available, I'd say TOP.

Andrea

ERsa Stringer, Matching & Custom, Trento

“Novak treats his racket like a scalpel. He's obsessed with weight and balance. We spent hours discussing how even half a gram of lead at 12 o'clock could change his ability to return serves.”

Andre Agassi

Rafa never wants his racket to feel different. His swingweight is tuned to generate that extreme topspin. If the racket is even slightly lighter in the head, the ball won't bite the court the way he wants. His racket is weighted with lead strips under the grommet precisely to achieve that specific swingweight.

Xavi Segura

“My racket is strange, I know. It's long and has a balance that many would find unmanageable. But for my flat, defensive style of play, that extra momentum allows me to hit very heavy balls even when I'm at full extension.”

Daniil Medvedev