Annoying creaking handlebar

[lawyering]

I have had some trouble with my handlebars slipping (rotating down) and I took them off, put a single layer of electrical tape around them at the spot where the stem attaches and tightened them up real tight. No more slipping.

Now when I put alot of pressure on them mashing up a hill or sprinting, I get an annoying creaking.

They are EMS Carbon Pro.

I am concerned I may have damaged them by tightening too tight.

There is no perceptible flex.

What say you all?

[ClemmonsHoo]

Mine were doing that after I put on a new Cinelli stem myself. The guy at my LBS that always works on my bike removed the screws from the stem and lubricated them before putting them back in. He told me to ALWAYS lubricate those screws. That worked for my problem, no more creaking.