Aerobars have been shown to save a couple of minutes over riding on the drops in a 40 km TT.
Why are the aerobars faster? Many riders, in the drops, have a flat back and seemingly-forward position without much frontal area relative to riding aero, at least it seems to me.
I realize that bike aerodynamics can be person-specific, but if the above is true, what is it? e.g., the greater width of the arms and shoulders?
Thanks and have a nice day.
Ken
Sometimes is not about aerodynamics. For me, I prefer to rest my upper body weight on my skeleton than to use my muscles to maintain a specific position. When riding for hours and hours, not in a pack (where you get the break of drafting), and not where you have to stop for cars, lights, etc. and where you get a chance to change position every so often, it is far easier to use my bones and not my muscles.
AP
In your aero bars your hands and arms are in a much narrower position in front of your chest to kind of “slice” (for lack of a better term) into the air before it hits your chest, kind of like the bow of a boat. When down on the drops your hands and arms are at the widest point, and can actually act as a “scoop” that funnels air into the center of the torso/hip area.
As an experiment, next time you are in a bar try to walk across the crowded dance floor without turning to the side to squeeze through groups of people. Just either put your arms in a narrow wedge in front of you (like aero bars) or low and spread out wide (like drop bars). Observe the difference in how many people end up running right smack into your chest vs. the number of people that just kinda bounce off the sides of your shoulders. How many times you get slapped will be determined by the elevation of your hands in each position and the average height of the ladies at the bar you frequent.
To answer simply but ambiguously, there is more to aerodynamics than mere frontal area.
It looks way cooler too.