I don't go by miles, depends on what the new bikes have to offer, if there are enough significant improvements, time to change, otherwise ride it until the wheels fall off.
Sorry friend. I didn't mean to mess up your otherwise scientifically accurate results. In order to restore the integrity of internet polling, I hereby promise that if I sell my Road King before 100,000 miles I will pay the mods whatever it takes to correct my vote.
I voted 100,000 out of solidarity for AtticusFinch.