I live on a typical dutch canal, which somehow ends up full of bikes. Mainly bikes like this. I regularly see bikes getting dredged all caked in the dreadful sludge, and amazingly, they still run! If you keep the chaincase closed they practically last forever. The bike I ride when I'm over at my parent's place was bought new by my granddad in the sixties and still runs without a creak, the only thing that was replaced are the tires.