Re: cotton---I used to ride 100 percent in cotton---or nothing above the waist. Cotton is fine if you keep moving because a lot of sweat can evaporate. However, if you stop, the cotton gets soaked and heavy quickly, and if there is really high humidity it doesn't wick well. Once you stop, ..... after a really hard effort I could wring half a gallon of sweat (about three pounds) out of a cotton T. Without that 15 mph average breeze the cotton wicked Zero.

I stopped wearing cotton--and stopped riding hard ..... either or both work. if you live in even a slightly dry climate or one which isn't really hot while it is humid and vice versa, cotton is okay.

But that is what I have found, and what I chose to do. The rest of you---who cares?