Thanks again, to all for the info, i understand more about the Shengyi motor, and for the OP above for his 12000 mile report, great stuff,
I did find a video on Shengyi, by an American / Canadian, on a sponsored tour of the factory, the testing looks like they are really trying to push them motors to their limit.
Link to video =
HERE
Thanks to Woosh, for your technical spec and knowledge, especially regarding the 36V 17A controller.
The comparison you gave was perfect for me, two different motors being fed by the same 17A controller.
I do understand the torque figures are only relevant to the input, to the motor, i wanted a comparison of the two models of bike, in this instance, but i now understand that the motor can be pushed harder with more current, but not for me, i dont understand enough about electric motors to play that game.
I'm a engine person, and electric motors are a bit strange to me, with their input / output figures and how its converted into motion.