A medical probe includes a flexible insertion tube, having a distal end for insertion into a body cavity of a patient, and a distal tip, which is disposed at the distal end of the insertion tube and is configured to be brought into contact with tissue in the body cavity. A coupling member couples the distal tip to the distal end of the insertion tube and includes a tubular piece of an elastic material having a helical cut therethrough along a portion of a length of the piece.