Don't need to go there just yet. Again, depends on how aero you want. Looking for something in the ballpark of WT aero bikes? Forget it, the best you can do is a good counterfeit. Something a bit worse than a Tarmac (keep in mind the sl8 frame isn't exceptionally aero, the rest of the componets do a lot of work for it to test so well)? That's doable. These bikes don't have any aero develoemt done on them, so oot's mostly a matter of who stumbled into the right designs while taking inspiration from the big brands.
The easiest way to start getting an idea if a bike will be any decent is to look at these things:
1. Frontal area - at the speeds a bike travels, just having as little surface impacting the wind is the easiest way to reduce drag. So look for bikes with narrow tubes.
The front of the bike is the most important, so look for headtubes that get thinner in the middle - like an hourglass. This one is somewhat common, just because it's easy to understand and spot as something to copy.
Having as little fork crown showing under the headtube as possible. This one doesn't draw the attention so it's rarer to see it copied.
Example of both done well in 1st pic. The 2nd failed in the 2nd pic
2. Tube shapes - to keep it simple, you want pointy leading edges and smooth lines. Colnago y1rs is a prominent example, 3rd pic. Most won't be nearly as sharp as this, so just look for leading edges that aren't flat.
Also avoid sharp kinks like on the downtube, headtube and fork in pic 4. That's just no good.
3. Deep bottom bracket area. It's just faster. Example that's furter exaggerated by the bottle integration in pic 6
Then there are lots of small things that make small contibutions, but that's too complex to explain like this.
One thing I will add is downtube hugging the tyre. Unfortunately Hambini in his lazyness and cluelessness has convinced many to think that the downtube being closer to the front tyre is a universally good thing. It is in fact not. It's very easy to fuck up and make it worse. Scott have actually done real research on this. Their conclusion in last pic.
