The week everything went wrong on a single e-bike conversion

I had this one week back in March where I was building up a cargo e-bike conversion for a customer. First the motor wouldn't even spin up, turned out a pin in the connector was bent. Then I mounted the battery rack and realized the bolt holes didn't line up with the frame bosses by about 3 millimeters. Had to drill and tap new holes, which took forever. After that I got the wiring all tucked in nice and then the display screen just stayed blank. Spent two hours chasing grounds before I found a tiny break in the speed sensor cable. By the time I finally got it rolling, the customer came in and said the torque arm I installed was rubbing on their spokes. Has anyone else had a build where like three separate parts all fought you at once?

2 comments

2 Comments

abbyr961mo ago

Make sure you run a torque arm on the outside of the dropout not the inside.

iris_mason881mo ago

Yeah I learned that one the hard way on a Bafang BBSHD build a couple years back. Put the torque arm on the inside and the nut kept loosening no matter how tight I got it. Ended up ovaling out the dropout a little before I caught it. Swapped to the outside with a stainless steel washer and never had another issue.