I think
that's unlikely. There is a tunnel erase head which essentially
wipes out any old data that might be picked up by the read head.
You mean that the
erased trace is guaranteed to be broader than the area that
can be sensed by the read head?
Almost.
Unless you switch drives.
The erased trace is "guaranteed" (designed) to be broader than the area
that was written by the write head.
Remember that the ORIGINAL 48tpi 5.25" floppies had "data" about 1/3 mm
wide in the middle of a space about 1/2 mm wide.
But, 96tpi had "data" about 1/6 mm wide in the middle of a space about 1/4
mm wide.
I think that later 48tpi drives may have mucked about with (narrowed)
their track width to try to reduce the problems created by 96tpi drives
tunnel erasing only 1/4 mm of a 1/3 mm track. (If the 48tpi were made
with 1/6 mm wide "data" in their 1/2 mm wide space, then the interchage
problems would be reduced)