Perhaps we don't mean the same thing for "aero" bars? Proper triathlon aero bars have the arm rests on them and there would be a large improvement. But I cannot see ANY advantage in bullhorns as were pictured earlier on in this thread over any other style if those bars are all mounted the same height and do not have the aero arm rests. Do you mean those bullhorns to have the aero attachments for the arms?
I think we both know that the armrests themselves are for comfort and don't contribute anything to the aero advantage. So if the aero grip is in the same position then doesn't it make more sense to support it with a short extension from the end of the horns than a long extension from the stem area? All else equal the short extension will be lighter and stronger.
Of course the pictured bars don't quite achieve the aero grip, but there are other bar ends to choose such at this one which is 7.5" long and L shaped:
And, yes, I plan to use thick plumbing insulation at the flat/stem area to make it more comfortable (with the horns I'll never grip the flat/stem area anyway).
Other alternatives I'm considering entail:
-Hammering long wood dowels into the ends of these bars to close the triangle:
-Reverse porter-style bars instead of flop and chop bullhorns. With the extra horn extension I'll only need to worry about extending the grip towards the center:
