An engineer once told me that bicycles are designed to withstand some enormous number of vibration cycles before failure, with each cycle being the equivalent of riding over a cobble.  Something like a half million or a million cycles.  The engineer then told me that the design spec amounted to about 25km of cobbles. 

Paris-Roubaix has 53km of cobblestones.

Not surprising, then, that the Queen of the Classics played host to the strangest mechanical ever---Hincapie's broken steerer tube.  And we can pretty much count on one contender being taken out by a mechanical Sunday.  So I've created a poll so that the Cafe can weigh in on what will happen this year, with parenthetical examples of memorable mechanicals from the past.