Pro wrestler Buff Bagwell made a valiant effort to start up a motorcycle chariot racing league a few years ago, building this amazing prototype inspired by rigs from the 1920s.
Bagwell has moved on to the gigolo game following a serious 2012 accident (not involving the motorcycle chariot), and his dreams of a league seem to have faded into the sport's near-century of history.
The first iteration of the fad most likely emerged following the release of the 1925 silent film Ben-Hur. These rigs had riders on the bikes and in the chariots. Later versions got more adventurous, allowing the charioteer to control the bike from the chariot. Then they started adding bikes; first two:
Then four. Gasoline culture blog Silodrome unearthed this 1938 article:
Benjamin Starr at Visual News has a great write-up with more photos.