Originally Posted by Riveting

I'm talking regular stuff in pockets, not over stuffed. But either way, those pockets and bigger saddle bag are behind me, in my aero wake, creating zero extra aero drag, and in fact the saddle bag may be helping break up the vortex behind me, much like those tapered apparatuses behind 18 wheelers to reduce their vortex to conserve fuel. An up-front bar bag, traditionally flat-fronted like the one in the pic, is 100% extra drag, to the tune of what? 54 square inches (9"x6" give or take) of frontage. That's huuuge. "They" say just going from a vented helmet to an unvented time-trial type helm is one of the biggest and most significant aero gains an avid cyclist on a road bike can make, and the gains from those turbulent holes and extra surface area must be less than the 54 square inches of a bar bag.

But if bar mitts and and an upfront bag works for you, then go with it. I'm just bringing up the aero downsides to not using them. I have lots of heavier-than-necessary items I ride with, and accept the weight penalty because they're valuable to me. But I don't dispute that the weight penalty exists.