This at least intuitively makes sense. Smaller frames are filled in by the bottle while the large frame there’s a lot more air space around the bottle. Which makes me think… “We’re gonna need a bigger frame bottle!”
Slow down there. I’ve seen S bikes be slower with bottles filling in that area. It’s going to be brand/bike dependent. Can’t blanket statement this effect.
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Just a follow up, Cadamotus did publish their own aero test
https://www.cadomotus.com/en/blogs/cadowiki/testing-aerodynamics-of-new-triathlon-cycling-shoe/
So do we still think the QR VRP-i is 5-10 watts down from the Cervelo P5D? Numbers look pretty good.
Thanks for your other response - so without testing, it’s like flipping a coin really.
This comment has me intrigued…
The thing tempting me towards a bottle in the first place is that I have the new Cervelo P-series. The P5 frame is almost identical and has the bottle as part of the design from what I’ve read.
The only issue is having to use a few spacers to get it to work with the compartment (why it isn’t there on the P-series) - I could easily 3D print a washer to fill that entire gap though
Any ideas as to what the huge variability is in terms of calf sleeves?
It would seem to me that this is one area where you have less variation - unlike bottle placement and helmet, it’s unlikely in my mind to be affected by other factors of one’s fit since your shins are by and large hitting the wind first.
Calf size/shape maybe? But I wouldn’t have thought that there’d be that much variation - we’re all pretty much cylinders.
Playing with the drag crisis may be alchemy?
That’s what I wondered up above. I’m guessing it’s all about how the air flow behind the calf, less so about the front (well, maybe a combination of the two, but the shape of that calf muscle drives the difference).
There’s definitely a pretty big variation in calf shape as I confirmed with a google search (hope I don’t get creepy algorithm points for that) and apparently there are actually people with totally normal looking calves doing marginally different things to them for reasons.
Taking a look at this before and after, which one do we supposed would test faster with sleeves on?
I have no clue, the left ones looks smaller but maybe the right ones shape the wind better before sleeves?
The right ones do look closer to those calf fairings that we see British time trialists adopt.
If I had to guess, it’d be the smaller set closer to a cylinder that’d benefit since the larger bulb shapes the wind better on its own.
Though careful with your cookie settings. Ha ha ha. Reminds me of my summer internship where the first thing I searched for on the work laptop was baby pacifiers with a mustache on them (my wife was pregnant at the time) before I turned off cookies. All summer, every ad was for baby pacifiers with mustaches.
That is the million dollar question.
Wait, we’re talking about triathlon. That’s the 60,000 dollar question 
My uneducated guess would be that a lot of this depends on whether the frame’s downtube is designed to shield a water bottle. When I fiddled with the old bikes where the down tube was only an airfoil shape (Transition, nosecone Shiv, Gen 2 Speed Concept) any bottle that caused much of a deviation from the original shape was going to be neutral at best and a complete disaster in a lot of cases. My guess is you are more likely to see a benefit on the newer frames if you have a bottle that cleanly fills the space between the down- and seat tube.