Totally agree. But it is(was), too early for me to be asking the right questions. Interestingly, while it is fairly easy to find information wrt clothing performance in cold weather (e.g. CLO rating), I couldn't find much to chew on regarding hot weather. There are certainly important and relevant differences between rainy vs humid vs dry heat, and I assume, the apparent wind created at cycling speed is such that the best garment for hiking is probably not best for cycling.

For instance, I'd think that for competitive cycling, cooling fast is of outmost importance -- you ride fast and can get plenty of fluids handed to you by your support team while racing (and you are burning calories so fast that the main issue may not be ambient temperature) . Touring is a different activity, where fluid management also means carrying your supplies for what could be quite a long time, measured in days, meaning that you'll not push yourself as much and may want to preserve fluids. Think running a marathon vs hiking across a desert -- I wouldn't hike wearing the typical wicking polyester jersey used by runners. On the other hand, I doubt that marathoners would like to race wearing hiking shirts.

As an aside, I read somewhere that you are better off dousing water on your head instead of drinking it, if your goal is to reduce your core temperature...

Another family of issues pertain to "wardrobe management". I always wear grey/black because they look cleaner than white clothes. The impact of clothing color isn't obvious to me. Steel boat decks MUST be (off)white in lower latitudes, otherwise you can't walk barefoot at mid-day. OTOH, bimini's fabric tend to be of a much darker color (typically shades of blue), and do not feel hot, probably because it is always windy, and because fabric doesn't absorb heat as much as metal does.

On a semi related note -- I almost never ride when it rains. And when I have to, I dislike the feeling, largely because waterproof shells become saunas. So it becomes a game of zipping/unzipping to try to maintain a reasonable temperature. Staying dry is not really part of the equation.

anyways -- winter is here. Fleece time.