See other failures under 000.html.
From http://www.bustedcarbon.com/2010/05/bmc-tear-machine.html as of 2011/09.
BMC carbon-fiber "Team Machine" froken at down tube and head tube to read "Tear Machine".
Frame broke after hitting a car. Although this is not a failure just from riding, it is interesting in part because metal frames in a crash typically crumple but remain a single piece.
And because of the hilarious transformation of the name.
See also FAIL-157.html.