This is actually a rather difficult question to answer. It goes beyond what you want your bike for and tackles a rather controversial issue of determining the average statistical anatomical differences between men and women. So I'll tackle the less controversial questions first, and then we'll get into the meat of the issue. A classic woman's bike has a cushier seat, a shorter top tube, longer head tube, and narrower handlebars. Also, depending on the purpose of the bicycle (mountain bike, road bike, hybrid, etc.), the top tube can be dropped lower down, to accommodate for a more graceful mount and dismount. If you're looking for a comfier, more luxurious ride, then a women's bike is the ideal option for you. Any casual commuters or riders should opt for a less expensive, generally aesthetically prettier, and more comfortable bike, which completely describes the classic women's bicycle. The higher handlebars mean your back is not strained, your joints are more comfortable, and your hips are under less pressure. The shorter top tube means your body is not uncomfortably stretched out. Now, for the more serious riders, deciding where you stand on the women's bikes versus unisex bike issue, seems to be a matter of opinion. The essential argument behind having a bicycle line specifically geared to women is that proportionally, women and men are different. More specifically, a woman's center of gravity is lower, her legs are longer proportionally to her body, and her upper body tends to be narrower. Leading bike companies like Trek and Specialize jumped on the women's bicycle train in the early 2000s, then began fazing them out in favor of the unisex bikes in the last 10 years, specifically in the competitive biking areas. On the flipside, GIANT has fully embraced this style and started the Liv line, completely dedicated to building women-specific competitive bicycles. If anyone here has heard of the Dreyfuss Human Scale, then kudos. For the rest of you, don't worry, neither had I. The Dreyfuss Human Scale was around as early as the 1960s and was developed through the years as a reference point for industries and companies to understand how both male and female bodies interact with the world around them. Anything from tractors to a desk is going to take into account how male and female bodies fit in and interact with their environment. The Dreyfuss Human Scale findings indicate that there are no statistically significant proportional differences between men and women, instead indicating that as long as the height is the same, the rest of the body is proportioned very similarly between the sexes. The US Military found similar results from a survey of over 4,000 participants. Ultimately, everyone's body is different, and it comes down to what you're looking for. Female biking athletes fall on both sides of this issue. Some swearing by the best bikes for women, and some preferring unisex options. At the end of the day, it's most important that the bike feels right for you. If you're committed to speed and competition, consult an expert who can guide you towards the bike that is best suited for your body type.