This customer came to us because his Giant bike fitted with an XD 2 speed motor kit had stopped working and he had no idea why. As an aside, we know a little bit about these motors having visited the factory and had lunch with the factory owner and chief engineer on a trip to China 2 years ago. These motors are a highly efficient and reliable hub motors, designed to work really well up step inclines at low speed. My experience of trialing this motor is that the torque of the motor on hills rivals any 250W motor on the market designed for this purpose...however...the way this one was fitted was particularly bad.
Firstly the battery cells had been fitted into a none water proof bag and mounted on a very dodgy looking cradle with the controller, not bagged, and attached badly by cable ties. The battery, had no 'on/off' switch and could not be easily unplugged so was effectively always on. The battery was in fact the issue and was pronounced dead on arrival by me and later verified by our e-bike doctor of electrics, Chris.
We then discovered that the motor, an older model XD, was a lot wider than a standard back axle of the bike wheel (this motor was originally designed for a specific e-bike frame and not as a kit to go on a normal bike) and whoever had done the retro fit had crimped the aluminium bike frame on the back stays in order to make the frame wide enough for the motor to fit thus deeply compromising the integrity of the frame. So not only could we not fit one of our motors or batteries, the bike itself was damaged beyond repair by the fitting process. If you are getting a kit fitted by anyone, not just us, a good question to ask is will the fitting be reversible? If the frame itself has to be modified in order to fit the kit, you probably shouldn't be doing it.