Felt like ass on the bike yesterday. Not totally sure why, but if I had to guess I'd say it was the cold weather. Ride temp hovered around 45 and dipped to 41 at one point with frost still on the side of the road. During my 2x15 the legs kept bouncing back and forth between "YEAH BOY 400W" and "dude 320 is all I've got." Settling in at an even power was a no-go. What's odd (maybe not odd?) is that I still averaged the threshold power on the nose, even with the up and down power.