Converting a 1973 Motobecane 40T to electric power is easy.
You need an eTek (or MARS 0708 or 0708 motor). A motor mount from northernmike (or engineer your own out of aluminum...) A suitable controller. Space for batteries. Wire and connectors. A Magura 0-5k potentiometer throttle.
This page will be flushed out with all the fine print necessary to allow you to create a silent, but deadly, high performance electric Moby. Stay tuned. ;)