Definition of riders:
(n) :
A mounted person.
(n) :
An old Dutch gold coin with the figure of a man on horseback stamped upon it.
(n) :
(generally) Someone who rides a horse or (later) a bicycle, motorcycle etc.
(n) :
(now chiefly US) Someone riding in a vehicle; a passenger on public transport.
(n) :
(sports) A boarder, a person who rides a board in boardsports.
(n) :
(sports) A skateboarder