Types of Frames Generally, there are a few main types of bicycle frames that are available in both men's and women's sizes. The most common frame types are the road frame and the mountain bike frame. Generally, these frames appear similar across genders on modern bicycles, but bicycles designed specifically for women will feature shorter top tubes, shorter stems and narrower handlebars. Women-specific bicycles will usually come available in smaller sizes than men's bikes as well. To accommodate wider female hips, a wider seat is usually preferable, although seats vary drastically from rider to rider and need to be measured separately from the rest of the bike for optimal comfort. Mixte and Step-Through Bicycles The Mixte or Step-Through bicycle frame, which does not feature a top tube, has historically been referred to as a women's or girl's bicycle frame. These frames were popular among female riders for the ability to bike while wearing a skirt or dress, and the typical top-tube diamond frame style was referred to as a men's frame style. Today, these frames are used by both genders for anyone who needs to quickly mount or dismount a bicycle easily, but are generally designed for casual riding and not for competition. Benefits of a Properly Sized Bicycle Frame A frame size that is designed specifically for your dimensions, regardless of gender, will be more comfortable and more efficient in the long run. Properly sized frames make your pedaling stroke more efficient by placing the rider in the ideal position to transfer power to the drivetrain, and a properly sized top tube and stem will ensure that the rider distributes the forces of bumps and vibrations equally between their hands and rear end. Having the bicycle frame specifically designed for men and women increases the options available to an individual, so that a perfect fit can be found using seat tubes and stems to perfect a given frame size.