"Rick" wrote in message
hlink.net...

that was it's resonant frequency. So I filled the bars with sand. They
are
heavy, but the noise is gone.

You probably don't need to fill the entire bar. I'd probably try caulking
the ends first and see if that works. Jam some paper in about 3-4 inches
and
fill the end of the bar with caulk. Over the years, I've lost end caps and
rather than replace them, this worked pretty nicely (and there is always
extra caulk around).

My bar still had end caps. The noise was due to the resonant frequency of
the bar as a big chunk of metal, not as an organ pipe. So just plugging the
ends would do nothing. I agree though that I probably didn't need to
totally fill them to eliminate the noise. I'd worry though about the sand
mass slamming into & removing an endcap when I do my normal abrupt turns.

If the noise persists, I would think that the bar/mount attachment isn't
tight enough. It it is, there should be no vibration along the length of
the
bar (hence, no noise).

It's tight. Or at least as tight as plastic towers allow. I like thumping
things to hear or feel them resonate & have found some solidly welded masses
that can vibrate for a long time. The big ones are at a frequency below
hearing.

Lloyd