Long Johns in the fall. Come winter I use insulated riding pants (Scorpion). I also have a heated liner. I was comfortable well into the minuses last year.
Try real motorcycle riding gear. I know it sounds crazy, but it really works.
Make sure those puppies are tight. I had straps on a rain suit (they where a little loose), and the strap got caught on the footrest when I had to put my foot down. I realized it just in time to lean to the other side when I came to a red light.+1 on rain suit, +2 on layers .. when it gets really cold, long johns, insulated tough duck pants, snowboard pants, rain suit.. the only thing that gets cold is my thumbs.. and sometimes my ankles as I havn't rigged up somthing to keep the pants from riding up ... too cheeep to buy
That works for me, I also keep my body moisturized with moisturizer, dry limbs get cold fast.rain suit