A magnetic pulse generator for measuring wheel revolutions of bicycles includes a magnet and an attachment device for attaching the magnet to a component (or spoke) of a wheel. Damage to the component to which attachment is to take place is to be prevented, and the installation expenditure during attachment is to be reduced. Furthermore, the magnetic pulse generator known from practical application is to be improved in that it is applicable to components of various geometric shapes, in particular to round components of various diameters and to flat components spokes of various widths. This object is met with an attachment device that includes a housing that encompasses the component, and that is formed as a longitudinally slit tubular piece. Ends of the housing forming the longitudinal slit can be connected to each other in a positive-locking and/or non-positive manner, and a spacing (A) therebetween is variable.