I get a metallic creaking/pinging sound in my bar/stem when out of the saddle. It sounds like someone is tapping on the bar with their wedding rign or something. It seems to coincide with times when I am pulling on the bars. Is this normal or is it a sign that the bars or stem needs to be changed? Never crashed on this setup. It has about 7000 miles on it. They are Ritchey WCS 4-axis and Ritchey WCS bar.