Why do boy's bicycles have the bar across?
Question:It stands to reason that as boys/men can more easily get racked by falling on the bar. Wouldn't it make more sense if theirs were made like the girls bikes?
I have a theory, we'll see if anyone thinks the same.
Back in the 1860s when the "ordinary" bicycle was introduced (a bike with 2 wheels the same size) women wore dresses. The "drop tube" frame was so women didn't have to lift their leg and "show it off" as they got on the bike. The diamond "mens" frame was traditionally only for those that dared to wear pants.
Note: A diamond frame is actually made of 3 triangles- the strongest shape known- while a womens frame is commonly 2 triangles and a parallelogram. The parallelogram part that makes up the drop tube area is typically very weak so the frame section has to be built much heavier to withstand even mild use. In short, a diamond frame is both lighter and stronger than a drop tube design.
Anyway, fast forward 140 years. It has finally been realized that men and women have just as much to lose 'down there', and since most women wear pants or shorts when riding the industry has started to eliminate the drop tube frame. In fact, unless you purchase a very cheap bike or one meant for bumbling about most manufacturers have already phased out drop tube frames in favor of a compact diamond design.
Neither men nor women will get "racked" if the bike is correctly sized and set up for the rider except in extreme situations.
A WOMENS frame and a MIXTE frame are different in that a mixte frame uses twin lateral tubes that run from the head tube down to the rear dropouts, connecting at the seat tube as well. This indeed provides the "full triangle" construction but increases the number of triangles to 5 instead of 3 and is still weaker and heavier than a diamond frame.
What the F are bars doing there anyways? I mean, only logically speaking it does NOT belong there! If all bikes were designed like beach cruisers bikes would be more comfortable.
Too bad beach cruisers are so effing expensive.
But then, I have wondered why boys wear pants and girls wear skirts. That seems backwards to me, too. obviously, girls don't have the 'equipment' to hide.
Who designed things for us all, anyway?
Frame sizing allows for "room for the crotch" or stand-over height as it is known polite circles - generally roadies (guys and girls) look for about an inch and mountain bikers look for about 2". I do know guys that ride downhill bikes that have 6+ inches of suspension that ride with no standover height.
if your bike fits then stand-over height is not a problem top tube or not.
The top tube (what you called "the bar across") keeps the frame rigid so when you pedal that effort goes to move the bike forward.
If the frame is not solid your ride feels like a limp noodle, the energy goes up, down, sideways.
Some of what's called "lateral flex" is good, absorbs bumps in the road, more comfortable ride. Unless you're a pro racer you don't want extreme rigidity in the frame.
There's always some trade off of speed vs. comfort.
These days most of us ride what you call "boys bikes".
Bikes built for women or what's called WSD (women specific design) are more about shorter top tube, narrower handlebars, women specific brakes.
They look the same as "mens" bike but accommodate womens narrower shoulders, smaller hands, and proportions (longer legs shorter torso than most men).
If you're 5'5" woman please consider these bikes for a good fit.
While most of the major companies such as Trek, Cannondale, Specialized make WSD bikes now.
These designs were inspired by and perhaps the best are still the originators such as Terry and Luna Cycles.
The placement of the "top tube" -- the bar that you're referring to -- on a boy's bike creates a stronger frame. The top tube on girl's bikes I think was put there so women could ride bikes while wearing skirts and dresses.
In higher quality bikes, like road bikes, you'll see that women's and men's frames all have the top tube placement higher up, the way it is on boy's toy bikes.
When the bicycle was invented, women ALWAYS wore skirts or dresses, so a horizontal bar would impede riding a bike, so they made the top tube more vertical.
On mountain bikes, there are several WSD (women specific design) bikes, but the top tubes are pretty much the same as the mens. What changes is the geometry (the distance from the saddle to the handlebars may be shorter than the same size frame for men. But also, WSD depends on the body proportions on the women. Some women might fit better on a men's bike, and some men might fit better on a WSD.
Women's geometry usually has a shorter top tube and longer head tube for a given frame size. You are referring to the old style "mixte" frames so women could ride in skirts without showing too much leg (VERY 1890's, BTW).
Only cheap department store bicycles and cruisers have mixte frames anymore.
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