The REI Headwind pants are probably the single best cycling clothing purchase I've ever made. I'm going on 4 winters on them (so maybe 3-400 days) and they show ZERO wear whatsoever. They are good by themselves down to about 35F. Below that and to about 20F (lowest I go), I add a pair of long underwear. They are not tight unless you buy the wrong size. They are not really very loose fitting either. Just right, including narrow legs so they don't get stuck in your chain/rings.