Step-through frame
A step-through frame (also known as open frame, drop frame, or low-step frame) is a type of bicycle frame, often used for utility bicycles, with a low or absent top tube or cross-bar. Traditionally, bicycles with a step-through frame were known as "Ladies, "Women's", or "Girls, mainly for their advantage to riders wearing skirts or dresses. Bicycles with a high top tube (cross-bar), known as a diamond frame, were known as "Men's", "Gents, or "Boys. As a result of changing clothing styles since the late 20th century, descriptions that describe  the frame style, rather than the presumed gender of the rider, are becoming increasingly common. Variations. Mixte. One particular type of step-through frame is called a mixte. In a mixte frame, the top tube of the traditional diamond frame is replaced with a pair of smaller tubes ("lateral tubes", or "lats") running from the top of the head tube all the way back to the rear axle, connecting at the seat tube on the way. The normal seat stays and chain stays are retained. This provides the lower standover height of a step-through frame bicycle with a strong  diamond-frame geometry. "Mixte" (pronounced ) is a direct appropriation of the French word meaning "mixed" or "unisex". The usual North American bicycle industry pronunciation of this loan word is . A variant on the mixte uses a single, full sized top tube running from the upper head tube to the seat tube, but retains the middle set of stays. The FNCRM (Fédération Nationale du Commerce et de la Réparation du Cycle et du Motocycle) calls this style a "sport". Other named French styles of step-through frames, in addition to "mixte" and "sport", include "berceau", "Anglais", "jumele", "col de cygne" and  double col de cygne. Cross. Another type of step-through frame is called a "cross". The cross frame consists mainly of two tubes that form a cross: a seat tube from the bottom bracket to the saddle, and a backbone from the head tube to the rear hub.