On most trips I use Schoeller climbing pants. I have two pair of zip-offs and two pair of regular. They are expensive but are tough as nails and good for off-trail bushwhacking. They are expensive ($120 range) but last forever. I do a lot of high altitude travel where it is often windy and cold. Zip-offs are good for the Sierra where it is 90+ at the trailhead and near freezing at 14,000 feet. I am really cold-blooded - would freeze if all I had were shorts. As for the weight, about 12oz (Mammut)-16 oz (REI). I do not mind extra weight in clothes I wear - they are warm enough that I can go with lighter long johns that I carry on my back.

In the "old days" I used the wool long-johns, shorts and wind pants combination. You use the shorts over the long johns. This is a very "Pacific NW" 1960's look! In my old NOLS days (Rocky Mountains - high altitude)in the 1970's we used army surplus wool pants (very cheap), long gaiters, and light wind pants (both home-made). All the pants were double material in the seat.