The Castelli MIracolo Wool Long Sleeve Base Layer Cool conditions base layer with mesh construction gives the warmth of wool but won't wet out on high-intensity rides. Wait, a wool blend mesh baselayer for cool conditions? When Tao Geoghegan Hart wore a prototype of this baselayer up and over the Stelvio on his way to winning the 2020 Giro d'Italia, fans lit up Castelli's social media channels. The very conditions faced on that stage highlight where this piece excels: it provides a surprising amount of warmth by pulling moisture away from the body, keeping you warm enough, but the mesh construction means it's not too hot. It is very lightweight and great fitting under a jersey for high intensity, or for layering under a jacket.

The design is clean, with minimalist finishing at the collar, wrist and waist to eliminate bulk where you don't want it. Castelli even built the piece with a raglan sleeve-shoulder system to avoid a seam on the shoulder that would interact with a bib strap. If high intensity rides and huge efforts are part of your shoulder season racing and training, the Miracolo Wool Long Sleeve Base Layer should be your baselayer choice.