Is it more mechanical complexity though?More I read about integrated motor and gearbox units, more skeptical I become about the value add.
In my opinion, it's basically introducing more mechanical complexity, slapping more electronics prone to failure, making your bike's transmission more difficult to repair (on your own), creating a single point of failure, and all this at a higher cost!
Aren't we talking about ebikes here, and not about high powered motorcycles that would clearly justify the need of a gearbox?
C'mon, this sounds to me more like luxury than anything essential on eMTBs... It'll good for the business though!
Typical system now is 12 sprockets, 100+ links of chain (each composed of 4 parts), rear derailleur comprising 2 inner and outer links pivoting on 2 pins between a top and bottom knuckle, the bottom knuckle housing a clutch and a spring, then inner and outer cage plates sandwiching 2 jockey wheels each running on it's own bearing... etc etc (not to forget that all this is just hanging out as one of the lowest parts of the bike exposed to every rock and all the mud)
12 speed gearbox has 4 input gears, 7 engageable intermediate gears running on an axle, and 3 output gears. Yes there are a few parts associated with engaging the gears but it's probably just a handful of parts. Then 2 drive pulleys/sprockets and (optionally) just a single part belt or a straight run of chain that doesn't need to flex in every direction.
Seems simpler to me. No high low or B screw adjustment, no need to get the chain length just right for the gears to work correctly. No need to drop the suspension to check chain length. No trimming to get the derailleur to line up with the gears and no scratching your head and reaching for the derailleur hanger "adjustment" tool when the top gears line up perfectly but the bottom ones are a mess etc. No washing the crap out of the chain and then drying and re-lubing between every ride in the winter.