Lots of work into this build for shiny side up 2017 and is a late post but I finally got some time to put it up here. As for the build : I custom made the fat tire bike frame from customizing a mongoose fat tire bike. I customized a girvin linkage fork by widening it out to fit 4" rim and had to make new fork legs to work with the height of the tires. I made and mounted the fender headlight cowl, and made an extension seat post to get a little leg room. I used a moped gas tank, 26" fat tire mag rims with 4" surly tires, double springer brooks saddle , and mounted a beastly predator 212cc engine with 24mm mikuni carb and electric starter, custom intake header, custom exhaust, and running a comet torque converter for transmission.