Years ago a friend got a brand new road bike from a LBS. When he rode it, it had a click only when pedaling. It happened in every gear, mostly at higher exertion, sometime while pedaling easily. Took it back to LBS. They put it on the work stand, made some adjustments, but never heard any click when rotating the cranks. Friend took the bike home, rode it, and again the clicking. Back to the LBS. Eventually the LBS wrench took the bike for a ride and heard the clicking. What he discovered was that his shoe was hitting the loner-than-usual excess from the front derailleur sticking out, and when it flipped back it would hit the frame and make the “click.”
Dan