  We show that, in general, any type of radially-polarised paraxial twisted
optical mode carries only an axial total optical angular momentum (AM) ${\bar
{\cal J}_z}=\ell{\cal L}_0$ where $\ell$ is the winding number and ${\cal L}_0$
is a constant. This mode, however, is shown to have zero spin angular momentum
(SAM), so it is endowed only with orbital angular momentum (OAM) and no SAM.
The helicity is found to be proportional to $\ell$, hence radially-polarised
modes display chirality. When applied to a Laguerre-Gaussian (LG) mode our
treatment leads to a total helicity equal to $(\ell/|\ell|){\cal Q}$, where
${\cal Q}$ is the action constant. The factor $(\ell/|\ell|)=\pm 1$, depends on
the sign, not the magnitude of $\ell$ and so the result holds for any
radially-polarised LG mode however large the magnitude of its winding number
$\ell$ is. The magnitude of the action constant ${\cal Q}$ and hence the
helicity are diminished for all such LG modes of large beam waist $w_0$.
