Originally Posted by Heathpack

Yes you are missing something.

Aero is a huge piece of the speed equation for racing in which there is no drafting- ie TTs and triathalon and some track disciplines. For disciplines in which drafting is legal, road races and crits, staying out of the airflow has a much bigger effect than aero equipment. Which is not to say aero equipment for road racers is a load of hooey. It's just that the aero benefit has to outweigh other considerations. If you can make an aero improvement at no physiologic cost- ie you get an aero frame- that's nothing but a win. Maybe not enough of a win to spend whatever the literal cost is if you're a Fred. But certainly objectively a win if you're just trying to do what's fastest, if you're racing.

Some aero improvements are going to have a physiologic cost though- and then you have to weigh the pluses and minuses. Helmets are a great example- because the fastest helmets are always going to be either unvented or minimally vented. This might be fine for a 40K TT which takes an hour but be untenable for a 4 hour road race. In a road race, the loss of cooling would trump the aero benefits and you'd pick an "aero-ish" (but not aero by TT standards) helmet.

Ditto for TT vs Tri. Sometimes an aero helmet will come in TT (unvented) and Tri (vented) versions. The Tri people give up a little speed for the additional cooling, because their races are longer.

And before you Fredly Freds start moaning that this is all ridiculous, a few seconds of time doesn't matter- a few seconds doesn't matter to you. But a few seconds for racing cyclists is huge. In my last two TTs, I was 1 second behind my nearest competitor- which was the difference between first & second place in one and second & third in the other. I could gain that second by training hard (but I already train pretty hard) or racing better (working on it). Or I can buy a new aero helmet and I have a pretty good idea which one would be faster than the one I have now. And yep, it's used by the big league cyclists. But guess what? It will work just the same on me.