The Honda Z-Series refers to the lineage of mini bikes manufactured by Honda Motorcycles. Though Honda's official model designations are typically Z50A, Z50J, Z50M, Z50R and ZB50, they are more commonly referred to as the "Monkey" or "Gorilla" because of the way people are said to look when riding one of such bikes. Sales of the bike began in March 1964 with the Z50M model.