While protection during cold-weather cycling and aerodynamics are usually thought of as mutually exclusive, in which case we'd gladly sacrifice wind-stopping power and insulation to a bit of drag, leave it to the experts at Castelli to buck convention with its Sanremo 3 Thermosuit. After all, it was quite instrumental in bringing speedsuits to the pro peloton and its revolutionary Gabba jersey to the classics. We want to go fast all year long, so we can totally get behind a kit designed to slice through the wind with a streamlined fit, removing the constraints of bib straps, all while preserving the stalwart benefits achieved through the company's flagship cold-weather apparel. The Sanremo 3 places fabric panels at strategic locations to create ideal climate zones across your body while in the cycling position. The Windstopper X-Lite plus and 150 fabric is the first layer of defense against the chill on the upper portion, offering up 1. 4 billion impossibly small pores per square inch that keep body heat in and let moisture and water vapor out. This isn't just based on vague marketing copy, though; the science behind Windstopper X-Lite is measurable in a rating called CFM, which stands for cubic feet per minute, used to measure the volume of air that passes through a fabric in--you guessed it--one minute. In order to be deemed "windproof," a fabric must register a CFM of equal to or less than 1. 0. The Windstopper X-Lite fabric actually beats this rating, so you're virtually guaranteed a windproof top. The bottom portion is a mix of Thermoflex and Thermoflex Core2, using the former for areas that need more stretch, think the thighs and the back of the legs, and the latter in areas that need more protection like the front and knee area. Both versions of Thermoflex use hollow-core yarn to provide more insulating pockets of air as well as the ability to better wick away moisture. The whole Thermosuit is lined with a brushed fleece interior that sits softly against y...