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Tecnifibre Black Code 4s String Review

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Construction: Extruded shaped polyester monofilament

Color: Black

Gauge: 16G, 17G, or 18G

Length: 40 feet or 660 feet (reel)


Test Racquet / Tension
Tecnifibre TFight 315 LTD 16M @ 52 lbs


Looking to bring some extra bite to their string line, Tecnifibre has debuted a new version of its popular Black Code series of polyester strings. The new Black Code 4S trades in the original pentagonal shape for a new square profile that Tecnifibre says has 20% more power than Red Code and 15% more durability than Black Code. The string also retains Tecnifibre’s Thermocore technology, a multi stage heating process designed to create more flex and a smoother response. Having enjoyed my previous experience with strings from Tecnifibre, I was eager to hit the court and see how Black Code 4S performed.


I rated Black Code 4S on the lively side of firm when it came to power. While it is not a power poly by any means, I felt it had more pop than other polys that have a similarly firm feel. The power off the ground was easier to come by compared to Red Code and I felt it was a little livelier than the original version of Black Code as well. I had no trouble hitting with pace from both wings and was able to keep the ball deep into the court. Spin production was a major highlight of the string. It produced a level of spin very similar to other square polys like Solinco’s Tour Bite. The square profile allowed the mains to slide smoothly along the crosses, producing massive topspin off both the forehand and backhand sides. I could vary the margin on my shots with ease but the string did have a little bit more trouble when I wanted to flatten the ball out. There was almost too much grip, leading to a tendency to over spin the ball on shots I wanted to flatten. Spin production was also excellent on kick serves. I was able to get my serve to jump high off the court and away from opponents, creating plenty of frustration. The control on the string was excellent in the early part of my test. The fairly low power level and easy access to spin kept the ball dropping in at the baseline and I found plenty of sharp angles. I was able to consistently play aggressive and know the string would keep the ball on target. The control dropped more noticeably later in the test but it still played with enough consistency to keep me in rallies.


Feel / Comfort
The feel on Black Code 4S was still fairly firm. I found it to have better flex and ball pocketing than Red Code but people wanting a soft, luxurious response will still want to look elsewhere. The feel on contact was crisp and had a nice connected feel. There was enough flex to the string that volleying was solid for a poly. A bit softer response would have given me more confidence to attempt and execute drop shots and touch volleys more frequently. For a firmer polyester, I found the comfort of 4S to be pretty solid. Shots on the sweet spot felt clean and smooth and the vibration increase on off center shots was minimal compared to other strings on the market. Overall it is still a fairly firm construction and players with sensitive arms would want to lower the tension or potentially pair it with a softer string in a hybrid configuration.


The durability improvement that 4S offered over Black Code was readily apparent during my time with it. In prior play time with Black Code, I usually broke it somewhere between 5-7 hours of court time. I was able to stretch 4S to about 10 hours of use before breaking it. The square shape provided a flat surface for the mains to slide on, which seemed to reduce the amount of string to string friction on impact. Less friction equals longer life and I was impressed with the durability in the 17 gauge sample I had. The strings exhibited notching after about 2-3 hours but held on until a main snapped around the 10 hour mark. The bigger issue I had with the string revolved around it playability. After about 6 hours of use, the string’s playability shifted substantially. There was a noticeable drop in tension at that point and the trampoline effect became more pronounced and the string was more challenging to control. The response was a bit more erratic and I was sending more balls long for the last few hours of use. In the future, I’d like to string a couple pounds tighter initially and see if I could stretch a bit more time out of them before the playability drops off.


Big hitting players looking to add ridiculous spin to their game will want to give this string a look. The relatively low powered response and massive spin allows players to swing aggressively. It plays with a firm yet clean response and has enough flex to be dangerous around the net. The playability duration may lend itself to restringing a bit more frequently for some players but durability is impressive for a shaped polyester string. Overall, Tecnifibre Black Code 4S is an impressive entry that boasts solid power, smooth feel and enough spin to drive any opponent off the court.


About the Reviewer: Matt Locke currently serves as the Junior Programs & Development Coordinator for USTA-Idaho and is an active USTA League and Tournament player.




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