After pedaling my Cannondale Neo 1 more than a thousand miles I developed a very annoying creaking. It was driving me crazy. I was sure the bottom bracket or motor mounting bolts were causing the creak because it seemed to correspond to each rotation of the pedals. However, after servicing both the creaking continued.
Not to be defeated by the problem, I moved on to the other common causes of creaking. I checked the seat post, pedals, handlebars and even spoke tension. Yet the creaking continued. I was baffled. So I just started grabbing, twisting and jiggling every part on the bike. When I grabbed and jiggled the battery I heard the dreaded creak. When I moved down to the motor housing I heard more creaking. The plastic parts rubbing on each other was the cause of my creaking.
Clearly, lubricating the parts would be my best defense to eliminate the creaking. However, a petroleum based lubricant could decay the rubber and plastic components. Instead, I used a silicone lubricating grease with PTFE (polytetrafluoroethylene) that not only eliminated the creaking but also helps to repel water and stop grit and grime from getting between the parts.