It has only been in the Olympic games since Sydney in 2000 and the keirin track cycling is amusing everybody.
A pace-setting motorised bike - called a derny - leads the cyclists around the track, starting at 15 mph and reaching 30 mph before exiting the race with just over two laps to go.
Then it all goes crazy. The cyclists begin sprinting (and often crashing) to the finish line.
Great Britain's Becky James secured her place in the final of the women's keirin but the event has got lots of new fans.
Viewers particualrly love the derny.
How do we get that job?
Hilarious but also dangerous. There seems to always be a crash.