I converted my old ebike setup to a milder setup for the wife. She seems to like it now vs the older setup.
I'm using a Lyen 3077 6fet sensorless controller with my old Yescom 48v 500w motor. Battery power comes from 18s2p A123 and makes for a nice "assist". I got it up to 27mph. There is a 3 speed button and have still to add the on/off switch and regen button.
I put the ESC in the center of the bike, covered up the wires and the batteries are in the back.
[youtube]xgckNdzgxcc[/youtube]