A catheter, comprising: an elongated catheter body comprising a first tubular structure having first central lumen, a distal end and a proximal end; a deflectable section having a second tubular structure having a second central lumen, and a proximal end that is distal of the proximal end of the catheter body; a flat beam having first and second opposing surfaces (FA; FB), the flat beam extending through at least the second central lumen of the deflectable section, the flat beam defining a first sub-lumen and a second sub-lumen (19A; 19B); a puller wire configured with first and second segments (28A;28B) and a U-bend segment therebetween, the U-bend segment anchored to the distal end of the flat beam, the first segment extending through the first sub-lumen and through the first central lumen of the catheter body, the second segment extending through the second sub-lumen and through the first central lumen of the catheter body; a first compression coil surrounding a portion of the first segment extending through the catheter body, a second compression coil surrounding a portion of the second segment extending through the catheter body; a pair of first and second half-cylindrical brackets (66A; 66B), the first bracket being mounted on the first surface of the beam, the second bracket mounted on the second surface of the beam, the first and second brackets forming a hollow cylindrical body generally surrounding the beam at or near a junction between the catheter body and the deflectable section, wherein a distal end of the first tubular body covers a proximal portion of the hollow cylindrical body and a proximal end of the second tubular body covers a distal portion of the hollow cylindrical body, wherein the beam has longitudinal side edges with friction-inducing surfaces (E1; E2). an elongated catheter body comprising a first tubular structure having first central lumen, a distal end and a proximal end; a deflectable section having a second tubular structure having a second central lumen, and a proximal end that is distal of the proximal end of the catheter body; a flat beam having first and second opposing surfaces (FA; FB), the flat beam extending through at least the second central lumen of the deflectable section, the flat beam defining a first sub-lumen and a second sub-lumen (19A; 19B); a puller wire configured with first and second segments (28A;28B) and a U-bend segment therebetween, the U-bend segment anchored to the distal end of the flat beam, the first segment extending through the first sub-lumen and through the first central lumen of the catheter body, the second segment extending through the second sub-lumen and through the first central lumen of the catheter body; a first compression coil surrounding a portion of the first segment extending through the catheter body, a second compression coil surrounding a portion of the second segment extending through the catheter body; a pair of first and second half-cylindrical brackets (66A; 66B), the first bracket being mounted on the first surface of the beam, the second bracket mounted on the second surface of the beam, the first and second brackets forming a hollow cylindrical body generally surrounding the beam at or near a junction between the catheter body and the deflectable section, wherein a distal end of the first tubular body covers a proximal portion of the hollow cylindrical body and a proximal end of the second tubular body covers a distal portion of the hollow cylindrical body, wherein the beam has longitudinal side edges with friction-inducing surfaces (E1; E2).