Here's a different issue on winter tights: I have both an older version of the Sugoi firewall and the Pearl Izumi Amfibs (neither one has a chamois). The thicker fleece and wind proof material cause enough pressure on my patellas that it becomes painful fast. I also tried the Assos LL.uma S5 and I could tell it would be trouble on my knees within minutes. A couple of knickers I have (Shebeest and Assos), without windblock, will also lead to patella pain, just not as fast. What works best to avoid the pain is to have tights that are a size bigger than what you normally would wear. I stay away from the windblock fabrics because they are less pliable. Instead, I apply some vaseline on my knees before putting the tights on.

One of my friends has the same problem with her knees, and she also wears tights that are a size bigger than normal. I wonder who else has experienced this.