without knowing what specific parts you're referring to, it's tough to think of places to get them.
it may help if you provide specific info on the device the parts are (or were) in (such as names, part numbers, manufacturer, link to webpage purchased from, etc) and clear, well-lit, in-focus images of the parts or where they used to be in the device.
since there is no ebike troubleshooting request or info in this post, but is a post looking for parts, i moved the thread from that forum to the items wanted section.