Not at all. It's just a matter of compatibility. EM3EV controller is already wired for it. You can get a used CA here, or shop for a cheaper one and fidlle with the wires.
Recently i've seen a video of this guy building a battery box with black fiberglass tape, water activated, self gluing. Anyone knows what tape is this? Can't remember the website of the video now...
Putting the bottom bracket on the rear swingarm is a bad idea. This way you'll have no suspension on your feet, and every time suspension compresses, your legs will be pushed up!!!!
Sorry for bringing up such an old topic, but can anyone confirm this is the correct bottom bracket?
http://www.chainreactioncycles.com/br/pt/raceface-x-type-team-dh-bb-cups/rp-prod50929