Originally Posted by jamesdak

The main thing to remember is wool. With two years of daily winter riding under my belt I can say with full confidence that wool is superior to any modern technical fabric. Breathes better, handles a wider temperture range, does not get smelly, and keeps you warm not matter if it's wet or not. How much you need to wear will depend on you. I do fine with 3 lightweight wool layers down into the low 20s f if there is not any real wind.