Why are male and female model bicycles different in the between-legs part?

Question

Female bike:

Male bike:

Other than the basket in front, the only difference is that the female version is far more convenient to get up on and get back down from. And you never accidentally crush your "package" (as a male) when using the female model.

So why does the male version have that bar going straight from the front to under the saddle? I've wondered about this since I was a kid. It almost seems like it should be the other way around: the females don't have a "package" to accidentally and painfully crush.

I don't understand why either model would have the bar so inconveniently placed as in the male version.

There must be some benefit to this design which I don't realize. But what is that?

Answer 1

A triangle (i.e. a frame with a real top tube) is much stronger. As far as I’m aware the reason for women’s bikes is historical: Dresses and skirts.

If you can, get a “men’s” bike with a real top tube. It will be lighter, stronger and easier to carry over your shoulder. “Women” frames often also lack bottle cage mounting points.

There are some bike makers who no longer offer dedicated men and women bikes.

I see no way for a man to hit their testicles on a properly sized frame, unless in a crash.

Answer 2

Hmm, no responses from women who have actually owned a girl's/women's bike. As other answers have noted, the lowered top tube is to accommodate a skirt, and it's not because it's less revealing, it's because the design dates back to Victorian times. So you have to imagine what it's like getting on and off a bicycle wearing an ankle-length skirt with petticoats. Trousers were unusual for women, even for recreational wear, until the middle of the 20th century.

As another historical note, a major reason that late-Victorian women started wearing pants was as "rational dress" for cycling.

Answer 3

You are mostly looking at it the wrong the way round. The "male" frame geometry does not have an "inconvenient" top tube added. Rather, the "female" frame geometry has the top tube removed. (Or typically, at least lowered.)

The "male" geometry is the default form. As mentioned in other answers, a triangle is a very strong form that can absorb shocks in many directions well, for a relatively small amount of material / mass. Hence why the traditional diamond frame geometry is composed of triangles.

Nowadays, the strict division into "male" and "female" frame geometries is more and more broken up, because the thing that makes the step-through frame convenient for women wearing skirts actually makes it just as convenient for men with limited mobility or wearing heavy shoes or tight jeans or what have you. And conversely, not all women wear skirts today, so they can just as well use "male" frames.

Apart from cases where the extra strength of a triangle shape is needed (racing / off-roading), it is more a style choice nowadays. Racing bikes still have the traditional shape because a) the same strength with a different shape would need more material and thus more mass, and b) the UCI has essentially "fixed" the allowed shape of a racing bike to roughly a racing bike from 1950.

Answer 4

Just an opinion here. I always assumed this has nothing to do with bashing of sensitive parts against the frame as mentioned in some comments above. It has more to do with getting off and on the bike. If we are talking about casual city cycling and using bike as a primary means of transportation in town then women are more likely to wear skirts and dresses than men. With a classic frame design that has a near horisontal top tube, rider needs to raise the leg rather high to get on and off the bike. This would be inconvenient while wearing a skirt.

Addressing the second part of your question the top tube is there in a 'male' version of the bike because this is the most effective way to make the frame stiff and light. Female versions of the city bikes are often heavier as having no top tube requires additional reinforcements in bottom bracket area and some clever design decisions to make sure the bike does not fold in half under the riders weight.

Answer 5

Someone opined that skirts might get caught in the rear wheel. Yes, and in the days of my youth in the 1940's USofA, "girl's bikes" typically came with a net or pierced metal guard covering the upper and forward portions of the rear wheel to prevent just that.

Example:

edit: It is not a frame tube, but it is something "between the legs" and a difference between bikes for different genders.

Answer 6

ANSWER: the "low bar" shape was invented to allow women with long dresses and skirts to ride a bike more easily and to mount it without "being indecent". This also agrees with what I was taught as a child.

However no one has provided any links to these explanations, yet. I'll fill the gap by providing some useful links to the history of the bicycle that cover the OP question.

Evidence:

• Why are Men’s and Women’s Bikes Shaped Differently?

• Why Do Women’s Bikes Have Different Frames?

• Pedaling the Path to Freedom

• How the 19th-century bicycle craze empowered women and changed fashion

These article all confirm what I and other have said about the origin of the different shape, but also point out that this allowed a real costume revolution at the turn of 20th century, empowering women to become more independent.

Answer 7

The reason for the different frame types is historical; they were first produced with the horizontal bar as this was the most obvious and strongest form for the frame, but once cycling had become popular more and more women were keen to cycle. Unfortunately the ladies of that era typically wore large skirts which could not conveniently fit over the bar of the frame so manufacturers invented the strengthened open frame now associated with ladies bicycles. Later folding bicycles were also created which used the open frame in order to facilitate ease of production.

Answer 8

I have been riding bikes all my life, (at least since I was 7) and have been wearing skirts on most of them. All sit-up bikes where the rear wheel was near the seat had a kind of skirt guard. In Dutch called coat guard and added to all city bikes, whether with a top bar or with a step through frame.
Fully enclosed chain guards were the norm but half chain guards, only top and front, on others.

On all sit-up bikes I have used, I have ridden with skirts. All of those are step through frames or folding bikes.

Now I ride recumbents.
Recumbent bikes do not come in a male and female versions. But riding them in skirts is not easy, not because getting on and off, not because the skirt might get in the wheels or chain, but because of the position of the legs, them sticking out forward and even up makes it hard to keep the skirts in place.

I do not ride diamond frames, not because it is 'not done' but because I do not like the idea to lift my leg over the back of the bike. And even mixte bikes are uncomfortable to get onto and off, especially when you wear tight fitting trousers.