I don't think you can install mid drive motors on bikes. Mid drives are designed from the beginning to be that way.
To modify your non electric bike; the labor/machining would probably cost more than the bike and motor combined.
Options would be a motorized front or rear wheel. There are also motors that spin the wheel thru friction; like the old
dynamo lights.
Last edited by 1nterceptor; 05-28-19 at 12:47 PM.