The only thing I would have to say is the fat tire may have to go to make room for the chain. I had to do this on my bike, with reluctance. Theres two ways to keep the fat tire, the first is the most expensive, but since you have 3 speed hub, may be the best. A shift kit from Sick Bike Parts is about 200 dollars, but would allow the fat tire, and use of the 3 speed hub. The second which I dont like is mount the engine offset to the left side to allow the chain to clear. If a shift kit is not an option, then do what I did, and cahnge the tires to a skinnyer size. I went from a 2.25 to a 1.75, was unhappy buying the skinny things, but have come to love them. The Michelens stick great. There are still 80cc/66cc kits for sell right here in San Diego.
