  We investigate the axial-vector nucleon-to-delta transition form factors in
the framework of relativistic baryon chiral perturbation theory at the one-loop
order using the complex-mass renormalization scheme. We determine the available
six free parameters by fitting to an empirical parametrization of the form
factors obtained from the BNL neutrino bubble chamber experiments. A unique
feature of our calculation is the prediction of a non-vanishing form factor
$C_3^A(Q^2)$. Moreover, our results show a surprising sensitivity to the
coupling constant $\texttt{g}_1$ of the leading-order Lagrangian ${\cal
L}^{(1)}_{\pi \Delta}$.
