A chameleon & an unsung hero of my cycling wardrobe!I'm a cyclist of 30+ years but really haven't ever embraced the base layer thing (aside from using thermal base layers during the colder months). My philosophy was that as I long as I wore premium cycling clothing, that a base layer was totally unnecessary.
With a training camp in Colorado at altitude on the horizon, I ordered a couple of the weightless base layers thinking they'd come in handy with the unpredictable temps of the Rocky Mountains.
I wore each of the base layers I purchased during epic MTB rides that started at 10,000 ft & went up to 13,000 ft in the mountains. I was caught in a freak ice storm at 13,000 ft after a very long climb: I was SO happy that I was wearing my Pactimo base layer. I never overheated during the 8 mile climb nor did I feel wet & chilled after the temps dropped. It did a great job of wicking away moisture when I was hot but somehow avoided feeling cold & clammy when I was cold.
But this base layer shouldn't just be used in colder temps: it works very well in the heat as well. It's true chameleon of my cycling wardrobe. ;-)
It may have taken me 30 years to take the base layer plunge but I am VERY glad that I did!