When you get really angry at your bike and toss it like BjarneRiis did in the Tour de France 1997.
On the final time trial stage everything went wrong and Bjarne had enough.
See the incident on youtube by searching for "Bjarne Riis 1997 bike toss"
This term can be used around friends that either know of Bjarne Riis or are into cycling, seeing as this is a very famous moment in the history of the race.
Sean checks his facebook and sees a status update from Brian.