Super long thread at Endless Sphere forum when the Xiongda was first introduced. I followed much of it with interest several years ago,
I recall two complaints...
1) Motor did not freewheel well with the gearing system,
2) If you rolled the bike backwards, there was a risk of clutch sticking and stripping the hears.
I believe the motor actually spun in reverse to engage the climbing gears?

I also recall the admin over there was very unhappy with his motor. SO hopefully, you get some feedback. Post a new threadm rather than add on to the old one.
,

https://endless-sphere.com/sphere/th...8#post-1654825