I don't keep any one 'bike' for any length of time... all the parts that make up my fleet will inevitably be re-purposed into some other configuration when the need arises. The longest serving parts I have are a set of Shimano 105 hubs from 1992. The longest serving frame I have was made in 2001. I have several other frames and incomplete bikes that may or may not be built into full bikes over the next couple months.