This work studies propagation of different SH-SAWs treating various configurations using the cubic crystals Bi12SiO20 and Bi12GeO20, which possess strong piezoelectric effect. Possible cuts for the wave propagation are treated when an even-order symmetry axis of a crystal is perpendicular to the sagittal plane, and when some analytical solutions can be obtained studying propagation direction  in the crystals. Calculations of the phase velocity and the CEMC versus the layer thickness were carried out. Numerical results on propagation of the seven-partial Love type waves were also introduced for different electrical boundary conditions: metallized and non-metallized surfaces. Also, new dispersive SAW possessing single mode was discovered concerning direction  in various layered systems consisting of the cubic crystals. It is thought that the obtained results can be also useful in the application of inter-digital transducers for excitation of different SAWs in structural health monitoring. In addition, a theoretical study of three-layer structures consisting of widely-used weak piezoelectrics (GaAs/GaP/GaAs and GaAs/GaP/ZnTe) was also carried out.