Sleeveless base layers keep getting better and better, as this Castelli offering shows. It has taken some time for purely summer-weight base layers to win wide acceptance among cyclists. This is not just because the thought of wearing an extra layer in hot weather is counterintuitive, but also because cycling clothing companies hadn't quite cracked the code of fit, comfort, breathability, and how the base layer interacts with the jersey worn over the top. With the Core Mesh 3 Sleeveless Base Layer, Castelli has done a great job of developing a piece that hits those criteria with little if any compromise of one to another.
The Core Mesh 3 system is built from their own Magic Mesh 100% polyester fabric. Magic Mesh has considerable stretch, but the cut itself largely defines the general fit. Designed for cycling with a longer back and shorter front, it may not be practical for wearing off the bike, but it really gets the job done on hot summer rides. Magic Mesh doesn/'t retain water- at all- so it serves to pull moisture off and away from the skin immediately, allowing your high tech jersey to do it's job more effectively. This keeps the Core Mesh 3 from trapping moisture against the skin, so when temps are cooler, you are dry and comfortable, while when it gets hot, air movement within the mesh keeps the skin cool and dry. The minimalist construction and lightweight fabric feel non-existent under your jersey, and the polyester yarn is smooth, so the jersey won't catch, even on the very low profile seams. All edges are finished to prevent fraying or rolling up. At just 88 grams (Medium) the Core Mesh 3 Sleeveless Base Layer won't hold you back. In fact it will allow you to save energy and prevent overheating so you can truly maximize your efforts. Plus you can show off your rock hard deltoids and triceps when the time comes.