The ornamental design for a securingdevice for a generator fixed by a slideway on seat-stays of a bicycle, as shown and described.
FIG. 1 is a front, right perspective view of the securing device for a
generator fixed by a slideway on seat-stays of a bicycle showing my new
design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is an exploded perspective view thereof, the broken line showing of
a portion of a generator support being shown for illustrative purposes
only.