Knightriders (1981)

George A. Romero doesn't direct only horror movies, but his non-horror output is little-known and hasn't exactly earned a ton of money.  This film could not be more different than his better-known ones and concerns a motley group of motorcyclists who dress as medieval knights and travel about to stage jousts on their bikes.  It's a no-name cast apart from Ed Harris as the leader or "king" of the pack and makeup guru Tom Savini as his co-lead in a challenging "black knight" role.  There is probably no way this movie could have been successful since it is way too long for the rather slim storyline, but it remains sufficiently unusual  that it deserves rediscovery by a larger audience.