I just spent 3 hours chasing a clicking noise in my Domane. I pulled the seat post, pedals, checked the stem, fork, pulled the crank, check the bolts; and then discovered I had a bad drive side bearing, so I ended up replacing them. If it had a way to attached to the bike, I checked it. I was completely frustrated, and then while sitting there looking at the bike, I noticed 2 small bolts used to allow adjustment of the rear IsoSpeed, then realized I did not check those, and would you know it, that was the cause. I will say, everything has been cleaned and greased, torqued and riding very smooth.

My advice, check everything