Handlebars are the main control interface for your bike, so it only makes sense as to why they come in all kinds of shapes and sizes. Each bar is made to put the rider in a slightly different position depending on their needs. Mountain bikers usually ride more erect, so they require flat bars and riser bars, while the rigors of triathlon racing require a much more streamline profile.
When looking for a handlebar, try to visualize where you want your hands to go in front of your bike. Do you want a wide bar for improved handling, or something with deep drops so you can tuck into an aero position?
Materials are also important, while aluminum tends to be the most crisp, carbon fiber absorbs a lot of the high frequency vibrations that would normally bother the rider.
Ultimately, handlebars, like a saddle, are a very personal expression of your needs and riding style.Full Article