@$@! I guess I will build my own?

[prestoOne]

The idea is to convert a commuter bike without spending more than a new ebike.
I don't think this exists, does it?
conversion kit: Mid-drive motor, motor size not exceeding 500W, torque sensor.

I am thinking mid-drive because the bike has both hubs occupied with a nexus internal hub and roller brakes.
I am uncertain if the Nexus 7speed can endure the motor assist, does anyone have experience with this?

 

[Dewey]

Nexus IGH can’t exceed 48nm torque, I’d recommend a front hub motor with a torque sensor bottom bracket from grin tech, that wouldn’t stress it. I broke two Nexus 8 with my bbs01 mid-drive. The front roller brake would need to be converted to either a rim brake or disc brake if your fork has the lugs, or consider replacing the fork as well so you can fit a disc brake

 

[tomjasz]

What are you considering the cost of a new ebike to be? A really reliable kit that’s an easy build like Grin RTR(ready to roll). Will cost as much as low end, IMO, junk ready made builds maker direct. BUT those ebike.ca kits are really sweet.