for base layers i use this:-
http://www.fourthelement.com/dry_xerotherm.php
http://www.fourthelement.com/dry_xerotherm_plus.php i have this 4 peice set.
I bought these for going under my drysuit undersuit during long 3hr deco dives in the uk. They realy are great, i also use them for skiing and also on the bike in winter.
up top:- 4th element sleevless top and a soft shell windproof jacket and trail shorts for temps in the 10c to 6c.
6c to 3c ish i use the same as above but with the long sleeve top instead of the sleevless, and leggings under the shorts.
Below that i use the long sleeve 4th element top along with the sleevless 4th element top plus the soft shell windproof. Was good today at -7c up Llandegla 1st thing this morning
down below:- endura water proof shorts or trousers with leggings underneath. 4th element socks with Shimano mw80’s .
The forth element stuff is expensive, but it really is good stuff. Wicks the sweat away like nothing else ive owned. After a hard ride the outside of the tops feel wet, but the inside is bone dry and it makes you realise even in cold weather you still sweat alot. but also how good this stuff is at wicking away sweat. Best of all it aint bulky.
I have had these for years and they are still going strong and have been used for diving, skiing.