Luna Cycle just added 2 new photos to the FacePlant forum... with description:
Bafangs top secret new drive is basically a bbshd built into a lighter package for production bike with a torque sensor..... basically 4x the power of the bosch drive in a more robust more affordable unit.
But this engine fits only for special frames. It is known as Bafang Max Ultra Drive and already on the webside of Bafang.
Every year there is a 24h-Pedelec Race(assistance only until 25kmh, like German Street law) at the famous "Nordschleife of the Nuerburgring Racetrack" organised by Bosch: one team by Bosch itself(Bosch Factory Team or Worksteam? not sure how you call it), many other teams all using the Bosch Performance Line and one single team with Banfang MaxDrive(250W, not the Ultra with 1000W). The Bosch management was not amused by the result of their race
A pity that you won't be able to buy one in Europe (Bafang won't sell it, because they think there is no need for a bike you are not allowed to ride, except on your own property.
The problem why we do not have an ebike motor with a torque sensor, which fits for most bikes like the BBS02/BBSHD does, is quite simple:
The torque sensor of most Ebikes(old Bosch, but the new Bosch Performance Line, CX ...has a different solution) is around the axle of the bottom bracket(sorry, I don't know the correct english word for this part),
but you can see one here:
There is no space for this and they are quiet expensive, that's why Bosch changed the torque sensor they used(which they had to buy from FAG) around 2013 and now uses one of their own parts.
But they needed another gearing for this. Negative: if you ride the bike without assistance you can feel that you need more power than with a normal bike.
I made this video when I changed some bearings inside(how stupid is it to use no sealing for a E-MTB for 4600e and the main bearing failed within the first 1000km). It shows how the new torque sensor works.
The part with the gears can rotate at an axis when you start to pedal(same thing that happens with hub motors and why they need torque arms). I move the part in video like it this.
The torque sensor goes through this part, now it can't move any more, but the sensor measures this force and sends a signal between 0-2.5V to the controller.
It's a sinewave signal, there is a polish developer who build a small controller with bluetooth to generate this signal and can use it as a throttle (and has much more power(over 1200W) by using restitors)
Some hub motors use a simple sensor at the chain and measure this way how much power comes from the rider, but with a middrive this won't work as it would create an endless loop.
sorry for my poor english, I had to look up many technical terms because english is not my native language