Tecnifibre X-One Biphase

Tecnifibre X-One Biphase Review and Play Test

String: Tecnifibre X-One Biphase (17 1.24 mm)
Construction: Multifilament
Racket Used: Babolat Aeropro Drive 2013
Tension: 59 lbs
Cost: $21

X-One Biphase – What You Need to Know

I used the 17 gauge version and that only lasted me about 3 hours. Now I’m guessing there is a large market of players that would benefit from a string like X-One Biphase but compared to the versatility of NRG I think it’s a much more specific type of player. Specifically players looking for the strings to do most of the work. It’s a powerful string in the sense that the ball really pockets and releases in more of a trampoline fashion. For older players going to larger head size rackets that can’t take those big swings this is a good multifilament string to try.

X-One Biphase – What I Loved

It’s all about the power of this string along with a nice bonus that the strings don’t really move around too much. With a lot of “power” strings that can be a big and annoying issue. I enjoyed the string for flat serves and also the feel and control on volleys. Good string with doubles only players that like being at the net.

X-One Biphase – What I Hated

For anyone hitting with even small amounts of topspin durability is going to be a major issue. It’s a multifilament so you’ll see the string fray and break. The feel off the string bed is pretty generic so don’t expect a ton of great pop or crisp when you’re hitting the ball.


Like NRG this is a string that claims to be the most technologically advanced thing out there so you pay a premium whether or not that’s true or even beneficial to the playability of the string is another matter. Biphase is arm friendly and offers tons of power, plus tecnifibre has a lot of sales throughout the year, so it’s definitely on the pricier side but worth it if it’s the right string for you.

Who this string IS for

Players that take smaller slower swings that need a string to add a little extra power and depth to their shots. Specifically I’m thinking of players that use oversized rackets that tend to hit flat or with backspin.

Who this string is NOT for

For most players the string is too powerful and not durable enough to justify the price tag and constant restringing. I think if you’re having arm problems and you like playing from the baseline NRG is the smarter option of the two strings.

Final Verdict

Tecnifibre’s X-One Biphase is fine and essentially does what it’s supposed to do. It’s powerful, it’s arm friendly, the strings don’t annoyingly move around on you but for most players it’s probably not the best string option out there. Specifically for players with arm problems that take smaller slower swings this is one to try and see if it fits your needs. For everyone else I’d say you can pass on it until you reach that stage with your game and swing.