E-waste E-bike

This is NOT a working design. This is the initial mock up of a design, to determine how to make it modular, and adjustable. I'm uploading it as it is open source. And I want criticism.

Intentions of the design:

1. Adjustable for a variety of bikes.
2. Modular enough that components can be swapped out easily with moderate redesign.
3. The utilisation of common components discovered in E-waste to keep costs down.
4. Possible to quickly remove from the bike when locking in public.
5. Able to be built and used without the use of circuit boards.

Elements that need development:

1. Adjustable Idler arm on motor mounts for tensioning.
2. Cog teeth interface.
3. Low wear material for rollers.
4. Throttle.
5. Rigidity of the mount.

I believe this list is in order of importance. If you solve 1 & 2, you would be able to make a working prototype, to test if it works. This is my intention for the next step.

The throttle will be similar to a motorbike twist throttle. It will