Step two - measure the rear triangles of your frame. My Micargi came with a rear dropout-to-dropout measurement of about 115mm. The Nuvinci hub is somewhere around 140mm wide (plus I added a rollerbrake, which made it even wider). It wouldn't fit no matter how hard I tried to cram it into my frame. One method of spreading the rear triangles is described in this website: Bicycle Frame Spacing
. Since I already had an engine, shift kit, gas tank, etc installed on my frame, I didn't want to take the time to remove them in order to use this technique - instead I used a 12" piece of all-thread, two nuts, and some large washers. The picture shows the placement of the all-thread, and then I just turned the nuts, gradually opening up the frame. Note - only do this if you have a steel frame!! (see if a magnet will stick to your frame first). Aluminum frames apparently do not bend well.