There was a mysterious tick-tick-tick sound coming from my drivetrain, and it drove me nuts trying to locate the source.
Wasn't sure if it was the chain, rear wheel or BB bearings, the rear derailer. Home remedies and adjusting didn't help.
So I took it to a local bike shop. The mechanic there immediately suspected spoke threads frozen in the nipple. He loosened every spoke, squirted in some secret sauce on the threads, then retightened and trued the wheel. Problem solved. It could be that I live 3 miles from a beach.
If that can be considered a handicap.
Gary in Santa Monica