  We study the one-dimensional t-J-J'-model in the limit of small hole doping
$x$ and small $J/t$, $J'/t$. Special emphasis is put on the regime $J'/J
\approx .5$ where a spin gap is present at small doping and the undoped spin
chain is strongly dimerized. Using a perturbative approach and Luttinger liquid
arguments, we demonstrate for this non-integrable class of models that the
charge degrees of freedom behave as non-interacting spinless solitons in the
dilute hole limit. Our approach is also used to evaluate the energy and mass
renormalization of a single hole. Interestingly, the corrections of these
quantities are in powers of $\sqrt{J/t}$. At $J'/J=.5$ we construct a
variational spin-polaron wave function for the hole and find good agreement
with our perturbative results.
