NRG2 17 is one of Tecnifibre's "thinnest and most powerful string." It's constructed of 1,120 individual fibers bonded with polyurethane "to reduce shock during ball impact." Silicon Pyrogene Lubritec (SPL) is added to reduce elongation and improve durability "by 40%." Its Lubritec coating is designed to improve stringability. Available in 39' coils in natural color.
The two coils tested measured 39'6". Diameter ranged from 1.20 mm to 1.22 mm. Stringbed stiffness of 74 RDC units was recorded immediately after stringing at 60 pounds in a Wilson Pro Staff 6.1 95 (16 x 18 pattern) on a continuous pull machine. After 24 hours (no playing), stringbed stiffness measured 68 units, representing an 8% tension loss. Our control string, Prince Synthetic Gut Original Gold 16, measured 80 RDC units immediately after stringing and 73 RDC units after 24 hours, representing an 8.75% tension loss.
Tested for five weeks by 21 USRSA playtesters with NTRP ratings from 4.0 to 6.0.
NRG2 17 strings up easily. Its thin gauge and SPL coating combine to make cross string weaving painless. The SPL coating has improved the stringing ease of all Tecnifibre strings. As with most multifilament strings, clamps tend to discolor string slightly, but these "bite marks" fade and aren't severe unless clamps are adjusted too tightly. Unlike other Tecnifibre strings (except their TR line), pre-stretching is not recommended for NRG2. We concur. It has minimal recoil which allows the string to flow through grommets easily. Also, tension maintenance is normal without pre-stretching. Knots cinch up nicely and don't slip.
NRG2 17 provides exceptional feel and damping with above average power. Its thin gauge allows for good spin. Touch shots are impressively responsive and off-center hits are more forgiving than with most synthetic strings. Fraying does occur after several hours, like other multifilaments, but no more than usual. String movement and durability were average for a 17 gauge string. Five players reported breakage; 3 after 5 hours and 1 each after 16 and 25 hours of play. We recorded average tension loss 19% after 2 weeks and 12 hours of play.
NRG2 17 is ideal for players seeking superior playability, softness and spin. It's a premium quality (and priced) string, but its thin gauge keeps it from appealing to string breakers. Only one other playtest string has scored as high as NRG2 17 in overall playability (3.7), and no other synthetic string has yet come as close in feel (3.8). Tecnifibre has succeeded in making a soft, playable string without the usual tension loss associated with their products. Our playtesters obviously think Tecnifibre is on to something with NRG2.
(The string most commonly used is in parentheses.)
'This string plays great! The playability and power are good selling points." 5.0 all-court player using a Dunlop Revelation Tour +1.00
strung at 53 lbs. (Dunlop Max Comfort 17)
"This string started out playing and feeling good. It did seem to have a
greater initial loss of tension than my normal string. After
approximately 5 hours of play I noticed the string began to fray." 4.5
all-court player using a Pro Kennex Kinetic 15G MP strung at 63 lbs.
(Gosen OG Sheep Micro Jim Courier)
"I liked this string. Lots of playability!" 5.5 all-court player using a Prince Graphite II strung at 62 lbs.
(Gamma Infinity 18)
"I felt the string had very little 'pop' on ground strokes. I had to
work much harder to obtain power." 4.5 baseline player with moderate
spin using a Head Radical Tour MP strung at 55 lbs. (Prince DNA Helix
"Nice string overall. Held tension well." 4.5 touch player using a
Prince Precision 730 strung at 60 lbs. (Gamma TNT 16)
"Loved the feel of this string. Great touch and control. I felt
confident playing with this string. It was easy on the arm." 5.0
baseline player with heavy spin using a Prince Precision Response 660
strung at 58 lbs. (Dunlop Max Comfort 16)
"I liked the feel and control of this string. It felt good on off-center
hits, had little string movement, but lacked power." 4.0 all-court
player using a Yonex Cyborg 2700 strung at 55 lbs. (Gosen Super Tec Gut
"Good feel at first but lost some control due to the tension loss." 6.0
all-court player using a Prince ThunderBolt MS strung at 65 lbs. (Prince
Original Syn Gut 16)
"A good string for widebody racquets. Above average power, control and
overall playability characteristics." 4.0 all-court player using a
Cayman Pro Talis 110 strung at 55 lbs. (Cayman Spintex 16)
"Great feeling string and easy on the arm. Made me feel like John
McEnroe on the touch shots." 5.0 all-court player using a Prince
ThunderStick OS strung at 63 lbs. (Prince Syn Gut 17)
"This string had a nice feel, even after tension loss." 4.5 all-court
player using a Head Pure 110 strung at 63 lbs. (Prince Syn Gut 18)
"This is one of the best strings that I have used in both playability
and feel. I certainly intend to stock and recommend the string." 4.0
baseline player with moderate spin using a Yonex Superlong RQ-500 strung
at 56 lbs. (Velociti 17)