Why do bikes designed for men have that bar in the middle of it while female bikes do not? It seems like it should be the other way around
When modern bicycles were designed (and assigned sex distinction for their users according to the different frames), girls and women wore skirts, while boys and men wore slacks. Same logic at work as to why women traditionally rode sidesaddle on horses.
Added in edit: In case it wasn’t obvious, the missing upper support bar on “girls’” bicycles was missing in order to accommodate skirts.
I have wondered this forever, especially seeing boys doing stunts and suddenly dropping hard onto that bar. The tears in their eyes makes it seem like it’s totally backwards.
ETA: Yes, but why do they still make them like that?
Thanks Polycarp. But shouldn’t they just get rid of that bar in the middle altogether?
Related question: Is a blow (heh) to the crotch as painful for females as it is for males? I get that females don’t have nuts, but surely the labia & related bits are equally sensitive to blunt trauma?
Structuralially stronger. Boys still push thier bikes much harder than girls on average. You don’t see many little girls taking thier bikes down steep ravinnes or jumping over things on a dare. The risk of getting your gonads cracked is part of the thrill; if there wasn’t some inherient danger involved it wouldn’t be macho enough to impress you peers. It’s what separates the boys from the sissy boys. 
My understanding is that the “male” version is much more efficient than the “female” version. A female bike frame will bend much more, thus using energy that would be better used propelling the bike forward.
They are sensitive but I don’t think they are nearly as sensitive as man parts. I’ve taken baseballs to the crotch and never felt like I was going to cry from the pain. Most of the important stuff is fairly tucked away and doesn’t make much of a target. Getting socked in the boobs hurts a lot more, and its much more likely as well.
And all women’s performance oriented bikes are made the same way, because it’s stronger and doesn’t flex as much under load.
Speaking as a woman, an unfortunately-aimed blow to the girly bits from your bike’s frame - I’ve had “men’s frame” bikes since late high school - is pretty damned painful, especially if you’re leaning a little bit forward and most of the impact is in that area. It probably doesn’t compare to a guy landing on the frame like that, but it is something I don’t want to repeat again.
That’s consistent with what I’ve been led to believe. The frames on girls and women’s bikes were made to allow you to ride it while wearing a skirt or dress without the hem bunching up near your crotch and making you an indecent spectacle.
A triangle is an inherently strong structure, far stronger than the u-bend in a woman’s bike. Hence a man’s bike is simpler to build and lighter, hence cheaper.
Why bikes still have gender is just social convention. A woman’s bike is just as convenient if you (as a male) happen to be wearing a pair of tight jeans as they are for a woman wearing a skirt, and enough women go mountainbiking. In general, gonadal injuries aren’t factored into the bike design very often.
Also: women feel hits to the crotch as well. Though pain between individuals is hard to compare, my empirical and anecdotal evidence suggests that the pain is not quite as severe. Men are obviously more sensitive to glancing blows though.
(I may well be wrong. More field testing is required).
Ethelbert:I don’t think there is any substantial force added to the frame by your acceleration, at least at a glance. The top bar is there to keep the steering column from bending backwards from the weight you’re putting on it.
on higher priced older female bikes there was a skirt guard (solid panels or holes to lace cord or leather through) on the front part of the rear wheel, to keep skirt from entangling in spokes. having the skirt ripped off the rider into the spokes was another indecent spectacle.
in modern times i did see a convertible bike, the top bar could be bolted on/off. with the play in that fastening it probably did nothing but be cosmetic.
if a girl bike was ridden hard and abusively, like a boy would on theirs, it would crack the welds sooner or later.
My sister’s girlfriend had a nasty wipeout while we were mountain biking once. She has foam padding on her crossbar and part of her handle bars now, so yeah it hurts. Quick Google says, the clitoris has several thousands of nerve endings, but it hurts the way it would hurt if someone slammed the tip of your wee-wee.
When we get whacked in the gnads, the general effect is more like a labor contraction for women when it comes to comparable abdominal pain. My fiancee had an ovarian cyst rupture, and the doctor said the pain was probably comparable to a pointy-toed-shoe kick to my scrotum.
Commuter bikes for women may still have the lower crossbar (to accommodate commuting in a dress). Specific sports bikes (like mountain bikes and downhill bikes) will have the crossbars in the same place as the men’s bikes, but there may be other slight differences in geometry.
My mom had a bike with the girls’/womens’ style crossbar and metal guards around the wheels. When I was a child, I suppose I thought that the guards were just a fancy style feature, but in real life they were probably the skirt guards you mentioned. That bike was probably circa 1970.
Now, I don’t think I ever actually saw her wear a skirt or dress while riding, but she did say that girls bikes and boys bikes just looked different, and didn’t really go into the reason, leaving me to figure it out as I got older. It didn’t help that by the 1980’s girls didn’t always have to wear skirts or dresses and the only way I could see a girl riding in a dress was on TV.
The trend for performance mountain bikes these days is to have a sloping top tube (example). That’s mostly to accommodate suspension, but it also helps save your bits in a wipeout situation.
The thing is, I do ride my bike a fair bit - no rough trails - and I can’t see me ever riding a skirt. A long one would just get tangled up in everything, and a short one would just hike up to the point where I might as well just flash my panties to everyone and cut to the chase.
I have dropped onto that bar, and I really can’t say it’s anywhere near as painful as a guy. Painful, sure, but not to the point where guys go.
I asked this question of the couple who ran my local bike shop, being puzzled by the continued popularity of these frames when female cyclists generally don’t wear skirts. I was told it was to maintain decorum whilst mounting and dismounting, which is the only thing that makes sense.
That said, the standard lady’s frame is the most godawful piece of junk. They’re heavy, bendy and weak, and are best avoided. If you really must go for a female-specific frame then a better design is the Mixte (SheldonBrown.com, scroll down a screen).
True performance road and moutain bikes are the same for men and women. They make smaller sizes and larger sizes that change up the geometry, but they aren’t gender specific. I saw a Trek that had a lot of hot pink in the paint scheme, so I’m guessing that one was aimed at women.
Georgina Terrymakes bicycles for women that aren’t simply scaled down models of men’s bikes. They are specifically designed for the female form.