first I would like to tell you that I'm very happy with the half bike. Funny, easy to manage because small and simply. It is a very good exercise, I often ride it to the town centre to pleasure and for the little shopping to. That means that I ride about 20 KM go and back, which I ride almost every day. My legs are much stronger than when I just used to skate inline or ride a normal bike.
My Halfbike works well, I never had any problems with it. I don't like Sturmey Archer too much, the gear shift spring when I change from 2 to 3 or 3 to 4 is lazy, I have always to turn back the pedal an half turn before continuing pedaling ahead.
Personally I would have choosen a better gearshift then Sturmey and Archer.
I find the brake works wery well and I'm happy with it. Regarding the handlebar I would have preferred a slightly wider one. I think 5-6 cm would be enough to have the place for mounting bar ends and a bell eventuelly a light too.
With bar ends is easier to control the halfbike in the curves, I find better balance and precisions. To mount handle with bar ends I had to cut the handle because it was no place. I’ll send you a photo to show you my handlebar.
If I were you I would have two or more model of Halfbike. Basic and Deluxe par exemple.
Gearshift Shimano with more then 4 speed (7/8).
Shimano Nexus or Halfine.
But Great work the Halfbike is really good.