  We compute various (generalized) isovector charges of the octet baryons.
These include $g_A$, $g_T$ and $g_S$ as well as the unpolarized, polarized and
transversity parton distribution function (PDF) momentum fractions $\langle
x\rangle_{u^+-d^+}$, $\langle x\rangle_{\Delta u^--\Delta d^-}$ and $\langle
x\rangle_{\delta u^+-\delta ^+}$. The simulations are carried out on a subset
of the (isospin symmetric) $N_f=2+1$ flavour Coordinated Lattice Simulations
(CLS) gauge ensembles with lattice spacings ranging from $a\approx 0.086\,$fm
down to $a\approx 0.050\,$fm. First results on the breaking of flavour symmetry
and the low energy constants $F$ and $D$ are presented. While SU(3) flavour
symmetry violations are found to be sizeable for $g_A=\langle 1\rangle_{\Delta
u^+-\Delta d^+}$, these are quite small for $g_T=\langle 1\rangle_{\delta
u^--\delta d^-}$ and $\langle x\rangle_{u^+-d^+}$.
