Originally Posted by
FBinNY
It's hard to predict when an axle will break, but once they do, you'll get what sounds like a bottom bracket creak when you pedal hard.
Sometimes they remain dead quiet even after breaking. A friend's late 80's Trek with a 6-speed freewheel broke the rear axle on a Maillard hub and we never discovered it until he had a flat tire and we removed the wheel to repair it. The drive-side axle stub was obviously very loose so we fixed the flat and very carefully reinstalled the wheel just to get us home. No prior warning at all.