Over time, you may need to adjust the shifting on your Sturmey Archer internally geared hub - this is especially common on new bikes as the cables stretch and settle a bit. This is a very easy adjustment and can typically be done in a few minutes without any tools.
- Start with the bike in fifth gear.
- Shift to second, and give the wheel a spin to make sure it completes the shift.
- Turn the barrel adjustor on the shifter until the two yellow indicators are aligned with each other.
- Shift back to fifth gear and spin the wheel.
- Shift back to second gear and turn the crank at least one full rotation.
- Check again if two yellow indicators are aligned with each other.
- Repeat process if yellow indicators are not aligned.
Here are the factory instructions:
Finally, here's a video that shows the process (it's on a 4 speed hub, but the 5 speed on your bike is the same: Sturmey Archer Internal Hub adjustment.