When gearing up for cold weather cycling, we typically accept that things like fit comfort and aerodynamics will be sacrificed in favor of wind stopping power and warmth. Leave it to Castelli to refuse this sacrifice with the Sanremo 2 Thermosuit, a piece of kit designed to offer the aerodynamic benefits of a bulk free fit without the restriction of bibs all while preserving the benefits you'd expect from the company's flagship cold weather technology. The Sanremo 2 uses a mix of fabric panels in strategic locations to create a microclimate in the sliver of space between your skin and the Thermosuit. The Windstopper X Lite fabric leads the charge on the upper portion, offering 1. 4 billion impossibly small pores per square inch that guard your microclimate jealously. They don't let wind in, but they do 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 considered truly 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 guaranteed a literally windproof top. The bottom portion is a mix of Thermoflex and Thermoflex Core2, using the former for areas that need more stretch and the latter in areas that need more protection. Both iterations of Thermoflex use hollow core yarn to increase the size and insulating power of that thin microclimate. The whole Thermosuit is water resistant and lined with a brushed interior so it's comfortable against your skin without any need of a mediating base layer. The fit is the same bulk free, race worthy fit you'd enjoy wearing Castelli's Gabba Long Sleeve Jersey and Sorpasso Bib Tights, less two elements: The bibs and the gaps. We often find that cold weather bibs are unduly constric...