It is mainly my right foot, but eventually the left goes numb also. I have to wear socks that do not have the seam on top of the toes (Defeet makes a no feel seam sock). They are probably medium weight socks. I wear a Body Geometry insole with one shim under each insole. I heard great things about the insoles and gave them a try, but still have problems. My bike has been professionally fit. No sciatic nerve issues. I'm willing to try new shoes next, but don't know which would be best. Any suggestions? Thanks.