Assuming like everyone else that it might be the headset... let me give you some other things to think about. How old is your R5000?

It could also be noise coming from the stem/handlebar area...that area takes ona lot of stress from all sorts of things.... road shock, we pull on the handlebars quite a bit when riding hard, and simply a portion of our weight over them all the time. That is why I asked you how old you bike was.. someting else to rule out. You might also check your housing where it feeds into the frame... that can also make quite a bit of noise.

If you aren't able to isolate the problem,: I would definitely have your LBS take a look at it.