5 commutes so far, and no sciatica or any other problems. (Even when I accidentally upshifted(!) my chainring instead of downshifting as I hit the base of a steep bit of hill, and had to jump up on the pedals with all my weight to keep the bike going forward - a really awkward/unbalanced thing to do on this bike.)

Very sorry to hear this. I have a seriously bad back and when it kicks in my bike sits idle for sometimes as long as a month.

Had to laugh at some of the irony in this post! I, too, have a pinched nerve in my back. The symptom is that it absolutely kills my right calf muscle. However, when my but hits the bike seat the pain disappears for however long I choose to ride!

Dang man, wish you the best and hope the surgery is successful at relieving your pain.