We decided to make a ring to center the sprocket. First we
machined the inside of the sprocket ring round again, as it
had little bumps where the rivets had been. Then we machined
the outside of the brakedrum in the area we would be centering
on. Finally we made a ring to fill up the gap and TIG welded
that to the sprocket ring with bronze filler. Then we machined
the inside of the ring that was welded into the sprocket to
a super tight fit on the brakedrum.