I imagine that filling the lower part of the open triangle is good or bad aerodynamically on a case by case basis. In other words, it highly depends on the shape of the frame and on the shape of the item doing the filling. And on it's aerodynamic interactions with the bike and a pedaling rider.

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
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Thx for the reply.
I have seen Tim Reed have it like in this pic. So my questin is: does it give more drag, less drag or drag neutral?
(i also got a Speed Concept like this)

I Tested that bottle on a Shiv TT and seen it tested on a Transition. Basically aero neutral at the yaw angles I tested. If I had to guess, I would say it is likely to make no real difference on an SC. The Kahm tail down tube mimics a 9:1 airfoil, which theoretically "fills" that space.

Okay cool, thx

Was the testing done with a rider (or dummy) on the bike?

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
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I'll have to look back at some of my old A2 data, but I tested that bottle on my old bike (Planet X stealth)
As I remember it wasn't "neutral" exactly... a little worse at 0 and a bit better at yaw. I'll have to see exactly what the #'s were though.

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My Blog - http://leegoocrap.blogspot.com

Less Drag if relative wind is from direction of travel.

If relative wind is not, then drag increases from 0 degrees to 90 degrees.

Drag decreases from 90 degrees to 180 degrees, and you then have sail propulsion.

I've tested a bunch of bikes with aero bottles on the frames.

The best answer I can give you is figure out how to become about 152cm (5ft) maybe 158cm and ride an XS or S frame and on some bikes a M.

The 2nd best piece of advice is you've got to carry fluid. Even if it dings you a bit, you're probably better off being hydrated and have enough calories that you can run closer vs further from your potential.

having to walk or shuffle never helps anyone move up the result sheet

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

A good experiment on filling the frame void...

That was predictable. Reminds me of the Trimble bike

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Or a J-Disc-bike thingy.



*If you are under 40 and don't know what a J-Disc is, ask Slowman.

It was with me riding, so basically a bike and dummy.

FTW !!

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
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The Shiv fuel cell is designed for the bike specifically and it's supposed to be aero neutral. (when i tested it it was slightly slower but within the margin of error).

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Coach of TriForce Triathlon Team

The bottle designed for the Transition was supposed to make the bike faster. No idea if it's true, but it's on my Transition all the time and hasn't been used in years.

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"...the street finds its own uses for things"