Isospeed Control Classic Review

by GP

Ferenc Ferdinand Weisz is back with a string review. This time he writes about the Isospeed Control Classic string.

Isospeed is the tennis brand of the Austrian sports manufacturer called Isosport. They are manufacturing nice co-poly strings like Black Fire or Baseline range, which I reviewed earlier, but I think the main strength of Isospeed is the multifilament. They are producing many multifilaments: Professional, Control, Professional Classic, Control Classic, Energetic, Energetic Plus, RIP Control, and Velocity MLT. Yes, the last two are Head strings but made by Isospeed, and these are all fine multifilaments.

Control or Professional, classic, or new line?

The concept is the same: producing this type of tennis string that imitates natural gut strings in the best possible way and protects the arm. The main difference is the gauge: Professional is 1.20 mm, Control is 1.30 mm, like in the new and classic collection, and I don’t know any other differences. The classic range was still available in the early ’90s and developed for smaller head sizes, tighter patterns, and tensioned higher. It looks glassy, and the whole string is pre-stretched. The new ones adapted are adapted to the modern game: more open string pattern, bigger head size, and lower tension. They’re not transparent, and only the core of the string is pre-stretched.

Why are classic ones still on the market?

Because these are known and liked strings. I offer five different strings in my stock, including one multifilament, because here the only players using multifilament strings are players with arm issues. I started working with new Control, but I got a request for the classic version. Then another customer who earlier played with the new version, tried the classic version and wanted to stay with that one – so I decided I will offer this classic version. A friend of mine who is a pretty good amateur player, playing Lynx/Control classic hybrid, used the new Control for the crosses before and changed it because he preferred the durability of that hybrid.

Classic meets classic

I’m not a multifilament fan. I earlier used the new Control after my (non-tennis) wrist injury. But I have a beloved Head Ti.Radical Mid Plus, and I thought this classic string would be nice in this classic racquet. I’m sure Control Classic was on the market when this racquet was released in 1999.

It is not easy to string. I decided on two-piece stringing despite being a big around-the-world pattern fan. People who have tried it, they know: weaving crosses is heavier in one direction, and with the 18×20 pattern and high-friction multifilament, this is too much for a comfortable string job. Tension recommendation is +10% (compared to co-polys) and also recommended a higher tension, but I went for 22 kgs (48 lbs). The reason is: I play around 24 kg with my spin machine, and I don’t want a stiff stringbed.

On the court: power, control, spin

The first hits were impressive. The response is very dampened but really exact. I think the dampened feel provides excellent arm protection, which eliminates harmful vibrations. I don’t remember the last time I met such an accurate stringbed response. The sweetspot of this 95 sq inch racquet is not large, and this string doesn’t extend it, but this doesn’t mean that outside hits are painful.

The thing that I don’t feel with poly strings is how I can hit with nice depth without much self-generated power, but I never felt how the ball is flying away from the stringbed. The topspin is much better than I expected, the launch angle is pretty nice.

Tension maintenance and durability

Factory pre-stretch is a really nice addition, because stretching during stringing is normal, like in a non-pre stretched co-poly. This definitely helps the tension maintenance.

This string is moving like other multifilaments. After some time, the friction of the strings wear the surface and start to wear the inner ribbons. With more topspin and a more open string pattern, this will cause fast breakage, particularly compared with any poly. If you hit mainly flat shots in a tighter stringbed, it will offer much better durability.

For example, a middle-aged, recreational customer of mine in a HEAD MXG 3 with 16×18 pattern, plays with this string for two months (weekly two doubles and sometimes singles and not any hard-hitting). A friend who is using this in hybrid reported 4-5 hours of durability in open pattern MXG 5. But not any risk of tennis elbow.


This playtest was a really nice experience. I can definitely recommend this string to players looking for a multifilament string and to anyone with arm issues. It works well in a full bed and a hybrid. I would echo one of the marketing lines from Isospeed: “Natural gut without having to pay for natural gut.”

Buy Isospeed Control Classic

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1 comment

Henrik Wallensten June 24, 2020 - 14:11

Nice review! I used Isospeed back in 2002-2003 and really liked it. I find it to be, without any doubt, the mult-string that is most similar to natural gut! Love it!


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