A catheter (10) shaft (12) is produced by forming a first polymeric layer (42) onto a flexible inner core (34) while maintaining the inner core in a solid state, and solidifying the first polymeric layer (42), wherein the solidified first polymeric layer (42) fails to bond with the inner core (34) and is slidable thereon upon flexion of the shaft (12). A second polymeric layer (40) may be formed over the first polymeric layer (42), and is slidable thereon when the shaft (12) bends.