Bikes for Women: the Frame
Looking at some basic bicycle designs as they apply to female riders
The frame is the core of every bike. This article looks at four basic frame designs: the diamond, 'lady's', mixte and compact, focusing on the needs of girls and women.
Women are put together differently from men. That’s not in dispute. It follows logically that bikes for women may well need to be put together differently too. However the traditional (I almost said old-fashioned) ‘lady’s’ bicycle is not the only, and often not the best, solution.
The frame is the core of every bike; if the frame isn’t right, then no amount of tinkering with other components is going to make the bike right. So let’s look at a few basic types of frame. It will really help here to look at the diagrams attached to this article. If you can get your browser software to display them in separate windows, so much the better.
In all these diagrams the main parts of the frame are shown in red, the fork in purple and other bits in grey. At the moment the red parts, the frame itself, are all that we’re concerned with.
The classic frame design, which some people may still refer to as a man’s frame, is shown in diagram 1. This may also be referred to as a diamond or twin-triangle frame, for reasons which should be self-evident. This basic design has been around for well over a century, in innumerable subtle variants, and is still going strong. It’s success is rooted in one simple fact: as any engineer will tell you, the triangle is one of the strongest structures there is.
The traditional lady’s frame is seen in diagram 2. This too has been around for a long time, originating in Victorian ladies’ need to reconcile their desire to go cycling with the dictates of convention that they wear long skirts. As such it played a vital part in the emancipation of women. However, it’s an innately weak and inefficient design compared to the classic diamond frame, because of the way the top tube joins the seat tube far below the seat stays. It’s inherently ’floppy’ by comparison and, other things being equal, requires greater effort from the rider for the same speed. However, for casual riding and commuting, its ‘step-through’ ease of mounting may still have an appeal. And it is still convenient if you do regularly ride in skirts.
One attempt to address these limitations was the mixte frame (diagram 3), where the top tube is effectively replaced by two extended seat stays. Although an improvement on the traditional lady’s frame in its handling and pedalling qualities, it is rarely seen on new bikes today.
A modern solution is the compact frame (diagram 4). Its sloping top tube means that both front and rear triangles are made smaller and therefore potentially both stiffer and lighter. While the sloping top tube first became popular in the early development of the mountain bike, it soon spread to road bikes too, and it’s now a common sight in the professional peloton - men’s as well as women’s. It has been a particular benefit for smaller riders, which includes many women.
For any woman who wants to ride far, or fast, or simply ride more easily, the compact frame is certainly worth considering. However, there are many more subtle variations in bicycle frames beyond these basic design, and this is going to take us into the realms of what is usually called bicycle geometry.
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