When it comes to socks, it really doesn't get any better than Merino Wool which is naturally resistant to odors and will wick moisture away from your skin. Wool is also much warmer and softer than synthetic fibers like polyester, but can also be quite breathable in higher temps. These are a performance weight sock however, that is thin enough for a close fitting cycling shoe but thick enough for trail riding as well. This sock has a 6 inch cut that will be great use all year round!