I can find a few examples of Belt/Rohloff/Bafang on the web. Details are scant. I will be converting my Soma Bside (current Belt/nexus/patterson drive) to Bafang/Belt/Rohloff. I would like insight on recommended wattage and chain ring size to fit over the Bafang housing. This will be long distance tour type bike. Anyone have some experience to share?