Re: Everything old is new again
I rode old British motorcycles as main transport for many years, and the vibration would routinely kill speedometers.
I rode a 1938 Argson tricycle across the Alps in 2011 and found the same problem - the speedo first stopped working and then dropped off altogether eventually. Minor issue though compared to the chain stretching, the idler shaft snapping halfway up a swiss mountain on a sunday etc etc.
BTW, we managed to find a garage on that mountain, open and they let us use their welding gear to fix the idler.