I'm looking for opinions from electrical engineer-ish Pelicans.
The question is, if one can build a concealed electric motor into the rear
rim of a modern bicycle.
The concept is: install rare earth magnets inside the carbon fiber rim, conceal windings in the seat stays and chain stays. Effectively treat the rim as the rotor and the stays as the stator. Assume you can conceal the battery and electronics in the frame tubes.
My feeling is that the distance between the stays and the rim (at least 20 mm at the closest point), and the limited surface area of the stays where they cross the rims, makes this impractical.
Here is an image:
http://cdn.velonews.competitor.com/files/2015/06/29.jpg
What do you think?