The 4 knots stringing is a classic now considered a standard and widespread throughout the world.
The tension applied to the vertical strings in this case is the same as that applied to the horizontal strings starting from the consideration that during the assembly of the horizontal strings, the presence of the pre-installed vertical strings implies a friction that will return an effective tension lower than the nominal one.
In essence, applying 24kg on vertical strings and 24kg on horizontal string will result in a differentiation of tensions due to the presence of friction during assembly and traction of “cross strings”.
The difference in effective tension between mains and crosses will be the greater the higher the coefficient of friction between the strings installed and the greater the higher the applied tension.
What do we expect from this kind of stringing?
From a 4 knot string with uniform tensions we expect a behaviour like a “race ready” racket.
A preferred choice for many professionals who want the ultimate in control and are not looking for a little help in terms of spin grip, thrust, tolerance and playing comfort.
|Racket used||Babolat Pure Drive 2018|
|String used||Signum Pro Poly Plasma 1.23|
|Tensions||24 / 24 kg|
|Real tension of the stringbed detected with pro-t-one chromatic S.T.D.||24 kg|
|Waiting time||4 hours|
|Real tension of the stringbed detected with pro-t-one chromatic S.T.D.||23.2kg ⇨ loss of tension -0.8kg|
|Rated dynamic stiffness of the top of the platter||38.3 DT-CH ⇨ the middle part of the plate: 34.5 DT-CH|
The stringing made with a 4 knot system “from top to bottom”, according to the rules now widespread at the level of major tournaments and without differentiation of tensions between vertical and horizontal ropes has returned a flat ropes with effective homogeneous tension equal to 24kg.
What is evident from the analysis of the rigidity detected in the various areas of the oval is the distribution that sees the concentration of the greatest rigidity in the upper part of the stringbed; area where the agonists love to hit in search of maximum control.
The difference in terms of stiffness is 28%, a significant amount especially in relation to the stiffness of the central part, the lateral parts and the lower parts of the stringing plane.
Laterally, the deflection stiffnesses are lower than the central stiffness, as well as that of the lower part, which are obviously influenced during the stringing phase by the friction between the vertical and horizontal parts.