Interesting. that is a legitimate BMW bicycle. no idea if it was a conversion, but the rear wheel hub motor being a mag wheel that matches the factory front might mean it was a factory deal.
For BMW, that thing was utter crap. the front fork was a Suntour, and it goes down hill from there. And it came from an erra when large corperations tried to sell things by adding an X in front of the name. the non ebike version was called the BMW X-Giant. It featured an X-Terrain Dynamic Frame sporting X-Giant 6 Spoke wheels, Shimano X-Treme Triptronic gear set, XCM fork, and a Motech X-3 crank set.
I think the motor was X-tra.
Here it is in non ebike form
