How do I adjust the gears on the Gen2?
On the hub, on the outside of the sprocket is a shift barrel that rotates when the gears are changed. On the top edge of the shift barrel is a small window. When 4th gear is selected, a yellow line should appear in the centre of this window. If the yellow line is not centred, adjust the cable tensioner on the revo shifter accordingly. You can also watch this video