Bought this for a kick bike conversion, but ended up having to do a 26" front wheel conversion as the rear drop outs were only 72mm and the 100mm 20" wheel wouldn't fit.
This mainly fits a front wheel 20" bike. Or if you're building an E-SUB stand up bike like the Schwinn Shuffle from Amazon this is perfect for the rear wheel. I've built a few of these bikes.
You can build a bike like this:
https://sacramento.craigslist.org/bik/d/pleasant-grove-schwinn-shuffle-bike/7892513412.html