Free shipping from 129 €
Free shipping from 129 €
Returns in 30 days
Returns in 30 days
Over 17,000 products
Over 17,000 products

Tennis String Iso-Speed Black Fire (200 m)


Recommended retail price

127.90€ Save 12 %
Buy and save with
Loyalty Program
We ship in 48h
Quantity Unit price
From 2 pcs. 118.90€
127.90€ * Iso-Speed Black Fire (200 m)
Featured products
Tennis String Iso-Speed V18 (200 m)

Tennis String
Iso-Speed V18 (200 m)

Save 5%
Tennis String Iso-Speed Control (200 m)

Tennis String
Iso-Speed Control (200 m)

Save 7%
Tennis String Iso-Speed Pulse (200 m) - white

Tennis String
Iso-Speed Pulse (200 m) - white

Save 7%
Tennis String Iso-Speed Energetic (200 m)
Tennis String Iso-Speed Energetic (200 m)

Tennis String
Iso-Speed Energetic (200 m)

Save 5%
Tennis String Iso-Speed Energetic Plus (200 m)
Tennis String Iso-Speed Energetic Plus (200 m)

Tennis String
Iso-Speed Energetic Plus (200 m)

Save 6%
Iso-Speed Black Fire (200m) The Iso-Speed Black Fire is specifically engineered to cater to... more

Iso-Speed Black Fire (200m)

The Iso-Speed Black Fire is specifically engineered to cater to the needs of aggressive, hard-hitting tennis players. Renowned for its exceptional control and acceleration, this monofilament string truly sets the bar for tennis equipment.

Main Features

The Iso-Speed Black Fire is available in an intimidating jet-black colour, giving it a stylish and cutting-edge look that matches its top-of-the-line performance. The 1.25 mm size ensures durability and optimal rebound speed, making sure you do not lose your tempo mid-game. Crafted from a unique blend of co-polyesters, the robust structure promises enhanced feeling, phenomenal control, dynamism, and longevity.

Furthermore, the smooth profile of the string compliments the player's swift movements by minimizing the drag, thereby offering a seamless swing. Moreover, with a generous length of 200 meters, this string is all set to meet your professional demands, ensuring there is always enough string available no matter how many racquets you need to string.

The Perfect Match for Your Tennis Racquet

Seeking the maximum performance from your racquet has never been easier with the Iso-Speed Black Fire String. Thanks to its state-of-the-art technology, it offers an optimum amount of power and control, making it a top choice among competitive players. In terms of impact, this exceptional string provides a solid feel upon ball contact, and its enhanced durability ensures it's resistant to wear-and-tear, even during the most demanding matches.

Product number: ST14743.1
String length (m): 200
String profile: soft
Structure: monofilament
Material: co-polyester
Properties: control dynamic feel strength
Main color: black
How to choose a tennis string? Tennis racket’s motor is its string – at least that’s how we... more
How to choose a tennis string?

How to choose a tennis string?

Tennis racket’s motor is its string – at least that’s how we say. And it’s true. Quality of the game depends heavily on the type of the string and on its string tension (measured in kilograms, between 20 and 30 kg). These days there are more and more new rackets on the market without strings. It results from the fact that every tennis player should choose string and its tension according to his/her own preferences. It is very often recommended to change the basic string (if a racket has it) after the purchase and make a new one. Tension which was used in the factory to make a string and time which has passed since that can lead to poor game quality despite the fact that a good racket has been chosen. While choosing a string you should take into consideration its flexibility and size. Tension with which string should be made is usually given by the producer and it depends mostly on durability of the frame. Strings have one essential disadvantage – they have to be changed regularly. Frequency of string changing depends mainly on strength of player’s strokes, frequency of game, string size, type of balls (heavy balls cause the string to break quicker), randomness (impure stroke at frame), string moistness (natural strings made of animal guts use to break especially often). It is recommended to change string at least once a year even if it didn’t break. It results from the fact that string loses some of its features over time, particularly flexibility because of temperature changes and tension which is reduced while playing. We don’t adjust string to the racket. We choose string considering game style and own preferences.

Types of strings

There are a lot of types of tennis strings considering the material they are made of and their construction. Regarding used materials we can distinguish: the least comfortable (‘wire’), more comfortable strings, soft (polyester strings), synthetic, the most comfortable, but also very expensive natural strings, which are the least durable. Considering structure we can distinguish monofilament and multifilament strings – very comfortable with a good combination of playability and endurance. There are variations in between these extremes: from core with single rim, with many rims, with extra outside rim (e.g cube cross section shape), till the use of different materials in the same string.

String tension

String tension is very important for control and strength of the shot, flexibility and durability of the string. Reducing string tension makes string more comfortable (better reduces vibrations) and elastic. The ‘trampoline efect’ appears which causes that power is increasing and control is decreasing. Higher string tension makes opposite reactions.


The size of the string especially affects durability and flexibility. The size of the string is specified in millimeters between 1.1-1.4mm. The smaller the size of the string, the higher the flexibility. The higher the flexibility, the bigger ‘trampoline effect’ and the faster the ball, however in the same time the more the flexibility the better reduction of vibrations (higher comfort). Bigger size of the string means harder string – worse reduction of vibrations – less comfort. Players that are using a lot of spin should choose a thinner string, because it helps to generate spin. But the thinner the string, the less durability. In addition size of the string depends on string pattern. Thinner size of the string should be chosen to close string pattern.

Playability and durability of the string

A lot of brands use designation „playability” and „durability”. Unfortunately the more playable string, the less its durability. The highest durability have thick monofilament strings while thin multifilament and natural strings offer the best playability. All strings currently available on the market are a combination of these two details and also a compromise between playability and durability. There is no string that will guarantee both of this parameters.
Rules worth to follow when changing the string

- thinner strings are better for generate more spin

- softer strings are reducing vibrations better then harder one

- thinner or more flexible strings allow to hit the ball faster

- thinner strings should be chosen for rackets with close string pattern and smaller headsize

- for rackets with high stiffness you shouldn't use very hard and thick strings

- stiff, monofilament strings are more durable

- multifilament strings are more comfortable, but less durable

- flexible strings give better acceleration then stiff one

- close string pattern (e.g. 18/20) gives better control, but less power and spin
- open string pattern (e.g. 16/19) increase power and spin while control is worse

- rackets with bigger headsize give better dynamic and spin but decrease control

- harder string tension gives more control but decrease power and spin

- soft string tension gives better dynamic and spin (“shots go more inside the racket”), but control and durability are wrose

- thinner strings are healthier and more playable but less durable

-thicker strings offer better durability

-flexible strings offer better comfort, especially for players with tennis elbow. At the same time it gives more spin and power while durability decreases

-stiff strings offer better durability, however comfort of the game and power are smaller


You are placing an order on behalf of a company registered in the EU, so the prices for your order are displayed in our store without VAT. After placing your order, you will receive a 0% VAT invoice along with your goods.