Honestly, I've had really rotten luck with any kind of fleece when the wind is blowing. As you know, there is always a headwind on a bike. So, to evade your question, my windbreaker is by Trek, and made of 100% polyester. It's incredibly thin, and very windproof, and seems to be worth about 15f in practice. I would prefer it had pit zips (underarm zippered vents), but you can't have everything in a garment that light and thin. I would also prefer the neon lime were colorfast.