First, the fibers are selected to provide the best
stiffness and strength beside cost consideration. It
is misunderstood that carbon fiber shafts are ‘‘too
stiff”. Indeed, what we meant by too stiff, it is
regarding the torsional stiffness rather than the
flexural stiffness. It is a best choice to use carbon
fibers in all layers. Since the fiber orientation angle,
that offers the maximum bending stiffness which
leads to the maximum bending natural frequency,
is to place the fibers longitudinally at zero angle
from the shaft axis. On the other hand, the angle of
±45º orientation realizes the maximum shear