Jumping in on this older post because I’ve had good luck with mid-weight thermal jerseys from Castelli and Pearl Izumi for that 40–50 degree range. They’re warm enough on their own but still breathe well, and you can add a light base layer if it’s closer to the mid‑30s. Has anyone here tried the newer lightweight wool blends? Curious if they handle moisture better on longer rides.
I recommend arm warmers.
Most of my winter rides have been around 40 deg. F at start and around 46-48 at the finish. I wear the following:
Merino wool sleeveless tank top, merino wool long sleeve, normal long sleeve jersey over it (helps compress & break the wind), super lightweight windproof vest.
It’s taken a while to get everything dialed in during these temps. Below I usually wear 3/4 length non-insulated bibs, normal socks, and shoe covers. I wear a thin pear of gloves with thicker pearl Izumi winter gloves over them. Pretty sure I have raynaud’s as my fingers and toes get insanely cold otherwise.