I wouldn't buy this bike for aero performance. I also wouldn't buy any of the currently available open molds for aero performance. I would want to see, at the very least, a measured reduction in frontal area and, at best, some data showing that, at least in simulation, the bike is aero.
The 266 has none of that. Mine is built and functions more as an allroad type bike.
I'm all aboard the wider tire hype train, but currently a bit frustrated with the current lack of understanding of the influence of frame aero drag to total system drag for rider + bike ... In other words, I have fomo over potential watts lost if I buy this frame. To me it seems as if e.g. Tour magazine and their test protocol magnifies the difference between frames, and eyeball aero really doesn't work. I'll gladly leave four watts on the table for a cheap, nice riding and versatile frame, but would I leave ten? Fifteen? Not sure.
Aero testing is still a minefield and I would not expect that to change any time soon.
- Tour's testing is highly repeatable. Still, it likely overemphasizes higher yaws. Despite their vigorous defense, the lack of a whole body does matter. Still, repeatable results would be nearly impossible with a whole body, as the bikes tested all have different geometries. This is basically as good as it gets for generalized conclusions
- Zero elevation and velodrome testing have the opposite flaw, the testing only includes relatively shallow yaws; but you can do it yourself pretty cheaply, so you can understand how aero you are, which ultimately is the thing that matters.
- Aerosticks can help you sort through data and simplify the analysis, but I don't think they get you better results. I believe the Gibli is the most advanced that you can currently buy and allows for some visibility into cross winds (not just that cross winds had an effect on airspeed vs. ground speed). However, it's still not good enough to significantly elevate the utility of this kind of testing above zero elevation or velodrome testing.
I've done the latter two kinds of testing, though my aerostick is on the basic side when it comes to usable functionality, and comparing bikes is a mess. For example, I know my custom, round tube, Ti bike is likely faster for me in most conditions than any other bike I have been lucky enough to demo or begged successfully for significant saddle time with. Those are also not fair comparisons because I got the custom bike to run a position that is not possible on those off-the-shelf bikes. The conclusion that I drew was that position optimization is far more critical than HT depth or a foil-shaped seat-post. Even if you are 10w slower because of a frame, at 48kmh 10w is something a lot of riders can find by narrowing their grip by a couple of CM and keeping elbows in. For many people, this is also less than the difference between a regular helmet and an aero road helmet. Or less than shoe covers, or in some slightly unbelievable cases, aero socks.
Regarding CDA optimization, I mentioned this on another thread that CD optimization is, at its core, a multivariate problem where it seems very possible that a shape that looks aero with deep shapes performs poorly even in comparison to a shallow one. Generally speaking, CD hard enough to optimize that its not easily predictable from person to person. You need to test to see if one helmet or brand of socks is faster than another, specifically for YOU. However, optimizing by reducing A is significantly more straightforward. If you can measure less frontal area, there is a very high chance that a small change, like keeping elbows tucked in, will be faster.
Unsurprisingly, reducing A is where newer Chinese frames like the Incolor Intropy and Evolve Cima have focused, given their relative lack of access to tunnel testing. The aero drag reduction achieved with aero frames is a real benefit for the few frames where it has been measured and proven, but in terms of cost per watt, an OSPW from Ceramicspeed seems like a bargain as these frames are around 2.5-3x the price of the 266.
