Warning: Awkward pictures follow.
The Gore Windstopper singlet is a tank-top-esque base layer. The front panel is windstopper, and the sides and rear are mesh. In use:
I busted out the Singlet tonight, for 40 miles on the Madone. When I started, it was 60 and windy…when I finished, it was mid 50s and windy. The singlet was perfect for those temps, with a short sleeve jersey. Pushing into the wind, the windstopper kept me plenty warm, while the mesh rear ventilated and kept me from getting too sweaty. Conditions were dry and sunny, and just about any other layer would have resulted in sweat being trapped. The singlet worked perfectly.
If I threw on a pair of arm warmers (like the Gore Windstopper armwarmers), this would be great well down into the low 50s. It’s thin, but it works at stopping the wind and keeping you warm (and dry).
My only criticism…I wear a medium, which fits perfect once it’s on. That said, the ‘head-hole’ is pretty darn tight to get on and off my head (I wear a L/XL in Lazer helmets). Post-ride, when I was a bit sweaty and trying to peel it off, it was a little awkward. I’m not sure how to go about fixing that without affecting the functionality of the singlet. If the neck hole was larger, it wouldn’t do as good of a job keeping the wind off of your neck. The stitching is amazingly nice, and it looks to be a very well put together piece of kit. I’d expect nothing less from Gore.
Anyhow, good gear that works. That’s how we like it.