DanTheMan wrote:Not having a pair of lightweight rain pants, I decided to put on OR Mentor Goretex pants to commute by bicycle in the rain. When I got to work about 15 minutes later I had a big wet spot on each knee. I don't think it was sweat, because everywhere else was dry. If the water repellent coating wears off does the Goretex lose it's waterproofness? For the price of these pants, and their intended use, I would have hoped they could keep me dry for 15 minutes in the rain.
It's not that the gore-tex has lost it's waterproofness or isn't breathable. My assumption is that you didn't open the side zips at the thigh on the mentor pants in order to vent while doing a high aerobic activity. If that's the case, it wouldn't matter what you were wearing (even eVent), it would feel wet from interior condensation (Paclite does this more so than ProShell because of the slicker inner surface, especially over bare skin) because you are simply overpowering the ability of the material to move moisture. It may seem ridiculous to open the side zips because then water can obviously come in, but it really just depends on your physiology on how much they need to be opened; even a little bit (like 4") can make a difference without letting much water in. At this point it is more a matter or staying comfortable than staying 100% dry.
Another question is have your pants been washed recently, or seen a lot of use since their last cleaning? If not, or they have seen a lot of use, I would suggest washing them and then seeing if that helped. Dirty gore-tex, especially from body oils and grime, is seriously hindered in its performance to move moisture. And putting in the drying on high will reactivate the DWR in case that has lost it's abilities as well.
And as mentioned above, if you have concerns about your product, call 1-800-GORE-TEX. You will talk to one of three people (they actually don't get as many calls as people may think) and they will be more than happy to discuss the issue with you.