I have a similar problem on my 5200. They (LBS) have dissassembled everything, checked, lubed etc... and the only thing that hasn't been replaced is the bottom bracket assembly itself. I still have the tick/creak. It drives me nuts!! I'm having a new BB put on the bike and hopefully that will do it. Everything else has been done. I even swapped both wheels from my 500 and the dam tick was still there!! Very frustrating.