Stringinging techniques: 4 knots with differentiated tension

Incordatura 4 nodi differenziata

The 4-knots pattern, which provides differentiated tensions between vertical and horizontal, is a widely used solution.

The maximum recommended tension difference between “mains” and “crosses” should be contained within 2kg of difference in order to avoid deformation and permanent damage to the frame structure.

The solution analyzed in this case has provided for the installation of 24kg vertical and 22kg horizontal to highlight the effects of differentiation of the load applied in the traction phase.

What do we expect from this kind of stringing?

The 4 knots stringing at different tensions is a variant of the solution with uniform tensions between vertical and horizontal strings, aimed at a search for greater grip of the rotations, power, tolerance and comfort of play.

The differentiation of the tensions, which can reach 2kg but not more so as not to compromise the frame structurally, has as its declared objective the enlargement of the sweetspot, a greater sinking of the sphere in the impact phase and a greater general tolerance on off-centre blows.

Advantages Disadvantages
  • greater power ⇨ greater output angle
  • optimum performance on topspin shots ⇨ less friction between ropes ⇨ maximum snap-back
  • increased comfort
  • greater tolerance in the game phase
  • less control
  • shorter duration of the equipment used

Sweetspot analysis

Racket used Babolat Pure Drive 2018
String used Signum Pro Poly Plasma 1.23
Schema 4 knots
Tensions 24 / 22 kg
Knot overtension +10%
Real tension of the stringbed detected with pro-t-one chromatic S.T.D. 23 kg
Vibration frequency 602Hz
Waiting time 4 hours
Real tension of the stringbed detected with pro-t-one chromatic S.T.D. 22.2kg ⇨ loss of tension -0.8kg
Vibration frequency 582Hz
Rated dynamic stiffness of the top of the platter 37.3 DT-CH ⇨ the middle part of the plate: 33.6 DT-CH

The differentiation of tensions involves a physiological softening of the racket’s stringbed, which has as its direct effect a greater feeling of comfort during the execution of shots in the field.

The homogeneous effective tension detected when the racket was just strung was found to be 23kg.

Compared to the 4 knots stringing pattern with uniform tension, the tension distribution is more uniform, as for the upper part of the plate as well as for the lateral and lower parts of the oval.

Logically, the upper part of the oval is once again more rigid than the central part to guarantee dry impacts that give a feeling of great control accompanied by an excellent tolerance guaranteed by the rigidity of the plate in the lateral areas.

In short, therefore, more comfort, more tolerance, more spin than a set-up with constant tension.