For performance, the types of bars people use affect frontal area of the rider confronting the wind. Wind tunnel tests have found that lowering the handlebars by 2 cm can reduce a rider’s wind resistance by 5%. This is about twice the benefit of aero wheels (2-3%)! Using handlebars that are 2 cm narrower possibly has a similar result, depending on what affect it has on elbow position.
Something else that handlebars have an impact on is breathing mechanics. When cycling, adopting a position which favours activation of the diaphragm is highly beneficial. Handlebars that are too narrow might be great for reducing the frontal area but can reduce the rider’s breathing effectiveness. This is due to increased upper back flexion and an inability to access the diaphragm. The result is ventilatory inefficiency and over use of the accessory breathing muscles about the neck and shoulders.
Despite the importance of bars, it has not been an area that has been researched to any great extent. Further, it is quite unusual for cyclists to do anything other than simply use the bars that came with their bike. Saddles and stems and seat posts get changed out fairly regularly. There are even saddle trial programs like the one we have here at Winning Position. But handlebars? Not so much. Even the elite and professional cyclists tend not to try different bars.
Why is this so? My hypothesis for this is that cyclists just don’t have the opportunity to trial them. Think about the obstacles involved. First you need access to a lot of different bar widths and shapes. Even restricting ourselves to common shapes and measurements you are looking at 72 different bars! How many shops or fit studios can afford to sink that much money into handlebars?
Then, if we have a range of bars available, the next problem is that it’s a chore to swap them over. We have to undo the stem face plate and take off the existing bars. (And work out where to put them as they are still attached by cables/brake lines.) Then the trial bars go on, the stem face plate is installed and the rider tries them. And then the face plate comes off, the bars are swapped and the face plate is attached again. Repeat ad nauseam. Very few people have the patience for this!
Enter the Profile Design sizing bars.