A deflectable catheter with biased deflection characteristics has an elongated catheter body having a micro-injection molded spine that is configured with a center core, outwardly extending opposing struts, and one or more sets of longitudinally-aligned and discrete fins, wherein the struts resist deflection of the spine in a first plane and bias deflection of the spine in a second plane, wherein parameters of the discrete fins define deflection characteristics of the spine in the second plane.