Dark Riders (Earth-90: Pre-Crisis)

The Dark Riders was a gang that terrorized Central City until the Flash dismantled it.

Lead by Nicholas Pike
At some point, Nicholas Pike became the leader of the gang.

Attack on Central City
In 1990, the Dark Riders gang caused chaos in Central City with their fabricated weapon called "Bio bomb". Due to their frequent attack at night, the police tried to create a squad that could take them down. At some point, Rick a gang member stole some money from Pike in order to leave the city with Lila, but she betrayed him revealing his loyalty to pike causing the gang to execute him. The night the police tried to promote their new motorcycle squad, the gang attack them and threw a territory mark on the station to humiliate them. The following night, the gang ambushed the new motorcycle squad and Pike killed his former partner as a revenge for betraying him. The next day, the gang was attacked by a red phantom that took them out in "a Flash" while they were robing chemicals for their Bio bomb. Lila who was one of the members was arrested and sent to prison. Pike would eventually try to cause a breakout but failed due to the intervention of "The Flash" demon causing his arrest and the arrest of most of the gang.

Trial of Nicholas Pike
In 1991, members of the gang were celebrating the release of their leader in from of the tribunal after he has been cleared due to a technicality regarding the murder weapon used on Jay Allen.

Trivia

 * It's the first antagonist organization on The Flash.