This past Sunday's 8am-11am ride was 51-55F light to moderate rain. As a top I only wore just a long sleeve wool jersey (EWR) and was warm. The jersey was damp (expect under arms and sides which never got direct rain and stayed dry) but I felt fine. Other riders said: hey you need to get real rain gear. I said why if I am warm? I have a rain jacket and I just sweat and get nasty under it.

right, skin was dry. merino sweater was dry also. I was so puzzled at first that I had to think hard if it had snowed or rained.

I took a couple of rides in Vermont this past weekend. I had forgotten to bring my jacket! (Duh, go to Vermont and forget to bring a jacket!) Well I brought a zillion sweaters, so it was fine. My t-shirt was merino wool. Then I wore a synthetic jersey. Then a wool jersey. Then a wool jersey. So four layers, three of them merino wool.

It was windy and cold, but I was fine.

On my legs, I wore modern (synthetic) cycling shorts, then a modern (synthetic) baselayer tights, then wool dress trousers.

On my head, I wore two synthetic beanies under my helmet, plus carpenter's goggles.

On my feet, I wore a pair of wool socks and a pair of neoprene socks and a pair of trekking sneakers.

On my hands -- OK this gets weird -- I wore latex gloves and then a pair of leather gloves. I read about this last week on bikeforums somewhere. As a result, my hands didn't get cold. They felt fine. Then when I took the gloves off, sweat POURED off my hands. But I didn't feel all that sweat while riding.