Tuesday, August 2, 2011

String Tension Loss

Strings start losing tension as soon as the machine stops its pull. "Creep", or tension loss resulting from the string's continuing elongation, can be measured in all cases: all you need is the proper equipment. Once you know what youu're losing, you can get a good handle on when to restring your racquet.
Why to Care
As strings lose tension, the launch angle of your shots changes: the ball stays on the strings longer, and comes off at a different spot in your swing. This affects how high and how far the ball flies. In other words, it affects your ability to control the location of your shots.
Everyone can absorb a certain amount of tension loss without a dramatic effect on ball control. Top players (top high school, college and pro players, along with high-level club players) will probably start noticing the diffreence at about a 10-15% loss in original string bed stiffness. Good recreational players and high schoolers will probably be OK in the 15-20% range. Lower-level recreational players, while they may not know it, will be affected at 20-25% lossses in tension.
Once you notice that your shots are flying a little long, it would be wise to have your string tension checked. A good stringer will have some way to determine string tension loss over time ("pinging" the racquet by their ear is NOT one), so he/she can better advise you on your options.
Whether they use a Stringmeter, Beers ert300, Stringway Stringlab, or Babolat RDC (the best, in my opinion), a quality racquet technician will be able to look in his records, tell you the original string bed stiffness, and see how much you have lost since the racquet was first strung. Many times, however, knowing how our strings react to tension will help us know before it's too late.
Different Strings, Different Losses
Below is a list of data I've taken on about 90 string jobs I've done recently, using different racquet and string combinations. From these jobs, the average tension loss in the first 24 hours was 8.95% (this is why many pros string their racquets every day). The best and worst strings at holding tension are in ALL CAPS. While there are a few surprises, a general consensus was found: natural gut strings generally provide the best tension maintenance (this makes them a better value than their price might suggest), while polyester-based strings (with a couple of exceptions) tended to lose their tension faster (a couple of polys showed low tension loss after 24 hours, but this is probably due to a loss of resilience). Solid-core and multifilament synthetics were mostly in the middle.
Brand Model String Tension RDC SBS 24 hrs Diff % Loss
Babolat P/D Cortex Gosen Micro 16 56 66 62 4 6.1
Babolat P/D Roddick Tecnifibre Biphase 16 60 70 63 7 10
Babolat P/S Tour Babolat Addiction 16 58 74 68 6 8.1
Dunlop 300G Tecnifibre NRG2 16 52 60 56 4 6.7
Dunlop 300G Tecnifibre Biphase 16 53 62 58 4 6.5
Dunlop C-Max 108 Prince Syngut DF 17 64 80 75 5 6.3
Dunlop Max OS 115 Gamma TNT2 16 57 71 65 6 8.5
Fischer M Motion Tecnifibre NRG2 16 55 65 59 6 9.2
Fischer Pro No. 1 Tecnifibre NRG2 17 56 63 57 6 9.5
Fischer XLite 98 Prince Lightning XX 16 58 69 64 5 7.3
Gamma Tour 330X Gamma Zo Verve 17 41 46 41 5 10.9
Gamma Tour 330X Head Sonic Pro 17 38 35 32 3 8.6
Head Airflow 1 Alpha Prodigy 16 48 48 41 7 14.6
Head Airflow 1 Wilson NXT 16 48 49 46 3 6.1
Head Airflow 3 Prince Lightning XX 17 48 50 44 6 12
Head F/P Rad MP VS TEAM 15L/MICRO 16 55 76 72 4 5.3
Head M/G Extreme Head C3 Rocket 16 53 61 55 6 9.8
Head M/G Extreme T/S Cyclone Tri/NRG2 16 55/58 65 59 6 9.2
Head M/G Ext Pro TECNIFIBRE BIPHASE 17 55 61 58 3 4.9
Head M/G Mojo Head C3 Rocket 17 55 63 56 7 11.1
Head M/G Monster Head FXP Power 16 55 63 56 7 11.1
Head M/G PresPro Wilson NXT Max 16 57 70 65 5 7.1
Head M/G Radical Prince Lightning XX 16 55 62 56 6 9.7
Head Ti.Rad OS Tecnifibre Biphase 18 59 69 63 6 8.7
Head Ti.S6 Gosen Micro 16 56/53 64 58 6 9.4
Prince S/P Black Alpha Firecable 16 55 60 55 5 8.3
Prince S/P Black Tecnifibre TGV 16 57 60 56 4 6.7
Prince S/P Blue Alpha Firecable 16 57 62 58 4 6.5
Prince S/P Blue BOW BRAND PRO/NRG 16 53 49 47 2 4.1
Prince S/P Red Tecnifibre Multifeel 16 60 64 59 5 7.8
Prince NXGrap MP LUXILON ALU POWER 47 52 44 8 15.4
Prince TT Hornet OS Gamma Syngut 15L 68 80 75 5 6.3
Prince Warrior MP Prince Syngut 16 DF 50 55 50 5 9.1
PKennex Ionic Ki-30 Gamma TNT2 17 58 67 62 5 7.5
Topspin Xtreme 100 AG 17 55 65 58 7 10.8
Topspin Xtreme 100 Prince Lightning XX 16 55 66 60 6 9.1
Volkl DNX V1 MP Tecnifibre Biphase 16 53 70 65 5 7.1
Volkl Tour 8 MP RAB Sensorfibre 16 53 66 60 6 9.1
Wilson BLX Pro Tour ASHAWAY COMPOSITE XT PRO 58 74 70 4 5.4
Wilson BLX 6.1/95 18x20 Alpha Firecable 16 54 61 56 5 8.2
Wilson BLX 6.1/95 18x20 Prince Nat Gut 16 42 51 45 6 11.8
Wilson BLX 6.1/95 18x20 Wilson Gut 17/Micro 16 42 52 46 6 11.5
Wilson HTour 95 Alpha Comfort Plus 16 55 66 60 6 9.1
Wilson HTour 95 ALPHA ELEMENT 16 55 65 57 8 12.3
Wilson HTour 95 Alpha Firecable 16 55 63 56 7 11.1
Wilson HTour 95 Alpha Gut 2000 17 55 67 61 6 9
Wilson HTour 95 ALPHA PRODIGY 16 55 65 57 8 12.3
Wilson HTour 95 Alpha Sphere 16 55 71 64 7 9.9
Wilson HTour 95 ASHAWAY COMPOSITE XL PRO 55 60 57 3 5
Wilson HTour 95 Ashaway Dynamite Soft 17 55 61 56 5 8.2
Wilson HTour 95 BABOLAT N.VY 16 55 68 59 9 13.2
Wilson HTour 95 Babolat RPM Blast 130 55 62 57 5 8.1
Wilson HTour 95 Babolat VF Int.Tour 18 55 71 63 8 11.3
Wilson HTour 95 Gamma Asterisk 17 55 67 61 6 9
Wilson HTour 95 Gamma Challenger SG 16 55 69 61 8 11.6
Wilson HTour 95 Gamma Live Wire Pro 16 55 65 59 6 9.2
Wilson HTour 95 Gamma TNT2 17 55 69 61 8 11.6
Wilson HTour 95 Gamma TNT2 Tour 16 55 66 59 7 10.6
Wilson HTour 95 GAMMA ZO VERVE 17 55 65 62 3 4.6
Wilson HTour 95 Genesis Heptonic 17 55 61 57 4 6.6
Wilson HTour 95 Gosen Powermaster II Spin 55 65 58 7 10.8
Wilson HTour 95 Head FXP 16 55 69 63 6 8.7
Wilson HTour 95 HEAD SONIC PRO 17 55 59 56 3 5.1
Wilson HTour 95 Iso-Speed Energetic 16 55 59 52 7 11.7
Wilson HTour 95 Kirschbaum P2 16L 55 62 57 52 5 9.1
Wilson HTour 95 Kirschbaum Pro Line I 18 55 64 58 6 9.4
Wilson HTour 95 Kirschbaum Spiky Shark 16L 55 58 54 4 6.9
Wilson HTour 95 Luxilon AluPower 55 61 56 5 8.2
Wilson HTour 95 Luxilon AluPower Fluoro 55 61 56 5 8.2
Wilson HTour 95 Luxilon Supersense 55 60 55 5 8.3
Wilson HTour 95 Luxilon Savage Lime 55 61 56 5 8.2
Wilson HTour 95 Prince Lightning XX 16 55 72 64 8 11.1
Wilson HTour 95 Prince Lightning XX Spin 55 66 61 5 7.6
Wilson HTour 95 Prince Premier LT 16 55 66 59 7 10.6
Wilson HTour 95 Prince Twisted 16L 55 61 56 5 8.2
Wilson HTour 95 RAB Sensorfibre 16 55 69 62 7 10.1
Wilson HTour 95 VOLKL V-ICON NAT GUT 16 55 57 55 2 3.5
Wilson HTour 95 Weiss Cannon Explosiv! 16 55 65 61 4 6.2
Wilson HTour 95 Yonex Poly Tour 16L 55 56 50 6 10.7
Wilson HTour 95 Yonex Tour Super 850 55 70 62 8 11.4
Wilson [K]sixtwo Alpha Element 16 57 62 56 6 9.7
Wilson [K]sixtwo Ashaway Comp XL Pro 60 63 59 4 6.3
Wilson [K]Zen Team RAB Sensorfibre 16 55 62 56 6 9.7
Wilson n6 MP WILSON SENSATION 16 51 55 47 8 14.6
Wilson n6.1 95 16x18 Tecnifibre Multi-Feel 16 57 63 59 4 6.3
Wilson nTour 95 Ashaway Kevlar/Gosen Micro 55 79 73 6 7.6
What this data tells me is that it's best to invest in quality stirngs for longer-lasting performance. Paying $60-plus for a set of gut may be worth it if you're not a string-breaker, as it will maintain tension and playability longer. Also, if you're wanting to switch to poly strings for more durability, remember the loss of tension and control that comes with it. You may be better off using a standard synthetic or Kevlar hybrid.

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