I run a half step 18 speed, 48x45 and a 12x36 9 speed. I run up and down on the rear and occasionally shift the front to keep a comfortable spinning rate. It has 18 non-duplicated gears.
I also run a half step 30 speed, 49x46x30 and a 11x36 and I ride this the same way, up and down the rear and change the front as needed and the 30 gives me a nice bailout.
