Since any savings come from an interaction with the frame, and there's no guarantee that this will be positive in your case. I'd avoid it. I would instead put a round bottle between the arms, which is proven to reduce drag considerably. Stuff your tube and co2 in there.

*disclaimer that I have no idea what the rules of your race are.

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'It never gets easier, you just get crazier.'

actually, the aero gains identified by Cervelo from a bta bottle have been hard to consistently replicate. Assuming you can get the trailing edge of the Torhans 30 a few cms from the headtube, you're probably more likely to be able to achieve some gains here than rolling the dice on the BTA. And I can't imagine this will run afoul of the rules any more than filling the same vessel with water ... the storage doesn't specify liquid, solid, food, or whatever.

(disclosure ... I've chopped the top of a torhans 30 and turned it into a virtual nosecone to store gels, a co2 and chuck, and a pair of contact lenses. It's well withing the 8.5x11 size limits, and if I'm ever challenged on it, I'll just point the official to a Trek draftbox, a Specialized whatever-the-triangle-filler storage box is called, or that rear brake cover on a p5 or Gain Trinity to illuminate what flouting the intent of the fairing rules looks like ... )

Does fairing from the bottle back to the nose of the fork improve it? I saw one guy basically taped the bottle to the front (see link below for pic, first in series)


http://lavamagazine.com/gallery-kona-2015-bike-checkin-continued/


Curious if you just had trailing sides to cover the larger gaps depending on your setup how helpful this would be versus just open and farther away. Still debating between regular bottle between arms and the Aero30 for drinking setup.