What's stopping the same materials and gear being used to create cold-weather cycling kit? Nothing, it's just that there's a lack of a need for it, because the roads would be unsafe at the temperatures it would be needed at.
That is my point. Hansen's letter cited the cold as the danger, but the cold is not what causes the problem, because, if equipped for it, they could easily race in the sub-zero temperatures. Hell, cyclocrossers already do on occasion. It's the road conditions at those temperatures that make racing in them unsafe for road cycling, not the temperatures themselves.
It's the reason that majority (99.9%) choose leg warmers or tights , the shorts are the issue w additional material adding to seat height and how the pad meets your junk and rear end and where the water drains. You can get covered from head to toe w shoe covers and jackets w elastic gaskets to keep out most water but nobody wants the extra bulk and " nature breaks " put you out of the race. If you have been there you know.. Have on extra layers w bibs and if you need to pee you go into full panic trying to get each onion layer off so you don't wet yourself!!
When you are doing a cyclocross race you don't get the same level of wind chill and your body temp gets to 1000 after first few dismounts and running! Pretty strange w all the comments and dedicated threads about crashing, what to do about it and organization did something fairly logical and now people are saying sport has gone soft and everyone is a bunch of marshmallows!!
Few years ago at our district road race it was comedy gold seeing riders trying to use cold weather gear w cycling clothing!! Helmet was 4 inches off their head trying to use hats and things to cover ears, gloves for downhill skiing, and tights ,leggings and shoe covers having people looking like Michelin man!!
I have owned a few pairs of Pearl Azumi Anphib tights and nothing bothers you, don't get too cold or wet but feels like a 3mm wetsuit!!
And for the record, I was an early adopter of GoreTex I bought cycling and camping stuff, super expensive and in my opinion it's not very good!!
When I watch the race and see how the rain jackets drain into the back crack in the shorts it makes me cold!!!
In Belgium and Holland they use some menthol vasoline looking mix to rub on your legs and arms to keep water off, Americans don't ride or race in rain!!