On Propain's website concerning warranty, nothing is mentioned about motors at all, no written information at all. They write about paint warranty, but really who cares about that. The motor fails and you can't ride for weeks, even months.
Propain told me that an end user cannot send back just the motor, the whole bike has to be send back to them or to the dealer you bought the bike from.. They also don't know who will pay for the shipping and they have no answer on how long it will take.