[RayOSV]

I've never tried any of the specific underwear for leather. REI makes long sleeve/long leg stuff in several different weights and neck height for hiking/backpacking at much more reasonable cost. I have 3 or 4 weights from minimum to fleece for different temperatures. The summer weight at least helps keep you drier under leathers. I use the long stuff even in summer so arms and legs don't stick when taking the leathers off. If it's really cold, I find a good windbreaker over my leathers (perforated) works better than heavy fleece under the leathers especially on long rides. YMMV