The invention relates to a securing device for head tube bearings of two-wheel vehicles, e.g. bicycles. The head tube bearing comprises a top and a bottom bearing unit, with the aid of which a tubular shaft of the fork of the two-wheel vehicle can be rotatably connected to a head tube of the frame of the two-wheel vehicle. The inventive securing device is composed of a thrust bearing which can be locked onto the tubular shaft above the top bearing unit and is effectively connected to a mechanism applying an axial pressure to the top bearing unit, henceforth referred to as an axial pressure mechanism. This has the advantage that securing the clearance of the head tube bearing is entirely independent of the handlebar fixture. The thrust bearing is locked in relation to the tubular shaft once the disclosed thrust bearing comprising the axial pressure mechanism has been placed on the tubular shaft and has been slid onto the top bearing unit until reaching the stop. The axial pressure is then applied to the top bearing unit by means of said mechanism.