Holes are drilled to enable {HEAD ~ the selective coupling} of a ball mount and {TAIL ~ a lynchpin} to a drop bar 
of
Holes are drilled to enable { HEAD ~ the selective coupling } of a ball mount and { TAIL ~ a lynchpin } to a drop bar
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH