Source = Armin König
"It is worth noting that the friction wheel has 3 longitudinal grooves, but no trace of the usual transverse grooves. This functional specificity could previously only be observed in Suhl pistols from the last production phase before 1634. The advantage of this design is that the relatively soft pyrite (pyrite) is subjected to significantly less stress and breaks less easily than if it is exposed to the considerable shear forces and impact points caused by transverse grooves. As the experimental test proves, the spark generation of the wheel is enormous despite the lack of cross grooves. However, the prerequisite for the perfect functioning of such a design is an extremely strong contact pressure of the cock spring and a rapid acceleration of the friction wheel caused by a very strong wheel spring. Both features that are not guaranteed with less high-quality and sophisticated locks."
Note - Brian Anderson says it was common on the larger wheellocks not to have many cross-grooves just due to the sheer power of the dog spring
"It is worth noting that the friction wheel has 3 longitudinal grooves, but no trace of the usual transverse grooves. This functional specificity could previously only be observed in Suhl pistols from the last production phase before 1634. The advantage of this design is that the relatively soft pyrite (pyrite) is subjected to significantly less stress and breaks less easily than if it is exposed to the considerable shear forces and impact points caused by transverse grooves. As the experimental test proves, the spark generation of the wheel is enormous despite the lack of cross grooves. However, the prerequisite for the perfect functioning of such a design is an extremely strong contact pressure of the cock spring and a rapid acceleration of the friction wheel caused by a very strong wheel spring. Both features that are not guaranteed with less high-quality and sophisticated locks."
Note - Brian Anderson says it was common on the larger wheellocks not to have many cross-grooves just due to the sheer power of the dog spring
