I was thinking about spring/summer biking attire today and wondered if a Smartwool microweight crew would work when I need something under my jacket for evening chill. I can't ride very fast near home, and wind off the river after sunset can be brisk. I know people wear wool in summer -- I've read about it here, but I've never done it. I don't do real bike clothes -- usually just wear T shirts in summer.

This is all in aid of rationalizing additional purchases, of course.