Originally posted by meehs
My new road bike has a 46cm Salsa Pro Road handlebar on it (and it measures 46cm center to center os it's WIDE). The bike that it replaces had a 44cm handlebar on it (which I believe was measured outside to outside). The 46cm bar on the new bike feels REALLY wide to me and I'm thinking of replacing it with a narrower bar.
What are the advantages and/or disadvantages of a wider or narrower bar? What size bars do you guys (and girls) run?
I have noticed a recent tendency for some manufacturers to have been specifying overly wide bars and overly long cranks on even mid-sized frames as the default.
The wider the handlebar is, the easier breathing should be and optimizes lung-capacity. Steering is more relaxed with a wider bar, but less responsive as more motion is required to effect the same angular change of the steerer tube. Aerodynamics is usually enhanced slightly by narrower bars, but I doubt if the difference between 40-46cm is very substantial for most riders in comparison to elongated TT bars.
Most "guides" recommend that you take the meaurement from the "distance between the bony protusions at the top of the shoulders", which is a sort of ambiguous measurement as most people I know don't exactly have the same slope and shape!!
It used to be that LBS's always wanted to outfit me with bars that were too narrow, now I find that it is almost always the opposite.
A lot of proper fit also has to do with what type of longitudal reach is most comfortable for you. As the handlebars are closer to you it is more comfortable to have the handlebars further outboard. I personally prefer a longer top-tube and a bit narrower handlebar. I personally (5'9" with a long torso for what that is worth) use a 42 on one bike and only a 41cm (center-center) almost antique Modolo X-Eras on another. I find that I am most comfortable if, when I am seated for the long-haul, if my forearms are more or less perpendicular with the fram when I am in the front of the drops (e.g. braking). If my wrists are outboard of my elbows at this point I rarely get comfortable. If I spent most time forward out of the saddle pounding than I could go wider.
I suspect that a lot of this trend has come from the tendency of the mass market towards smaller frames and the number of people who are used to riding flat bars on MT and hybrids.
One also need to take into consideration the vertical alignment of the drops in comparison to the flats of the bar, if you ride in a variety of positions. Like most things in cycling there is a fair amount of personal preference involved.