If you notice the third picture has a freewheel mounted on a bottom bracket and has five cogs on it. I have two paired together on the front kinda like a front chain wheel with a front derailleur to shift between them. On the outside the other three cogs have a rear derailleur to shift between them. All this is in addition to the regular front and rear Derailleurs. It is a middrive to give more gear multiplication up and down than is possible with a conventional setup. I plan to ride this thing a lot using pedals only and need the extra low gears to climb long steep hills and extra high gears to really haul down the other side. It gives me 126 gears, 3x3x2x7 = 126. There are a lot of duplications and overlaps but you do get some useful higher and lower gears.
I can take no credit for the design because it is built mostly from Greenspeed plans with variations such as using a rear triangle from a old bike and using
Fleet Trikes design for the front wheels.
It appears that it is going to take a really small engine to work on this one.
