It's all kinds of vehicles not just bikes, but there are I believe two events each year on the Bonneville salt flats in Utah vying for land speed records in multiple classes of vehicles that last for at least a week and draw competitors from all over the world.  In fact Burt Munro held a number of records there and he came all the way from New Zealand to do it.  They made a movie starring Anthony Hopkins about it called Worlds Fastest Indian.

The other event that comes to mind is the Pikes Peak International Hill Climb. It's been going on since 1916.  I think it lasts for 6 days.  Guy Martin competed in it this year and he did pretty well even though they couldn't get his Turbo GSXR 1100 to run properly.