The following post will have numerous photographs, both of the model I built as a guide for the real thing, as well as photos of the actual frame.

The overall shape I had of my velomobile can be seen in this partially-complete model:



The general size can be seen in this photo of my Dad holding up part of the frame:



It's basically going to be a pedal-powered van.

What I'm having issues with right now is the rear suspension:





The issue here is the frame holding the rear suspension. As you can see in this photograph, the ends of it are simply out there in the open:




To me, that looks terribly flimsy, so I thought I'd make it part of a rectangular frame that would also support the ends of the shaft with the drive sprockets (the reason I have sprockets on that shaft instead of having the wheels directly on it is so that I could give the rear wheels some suspension. The freewheeling mechanism is on the differential, the rear wheels are fixed-gear)

So, the rectangular frame looks like this:





But I'm worried it takes up too much space beneath the velo and might not give me enough room to put in the hub gear and (if I need it and I probably will), an idler that will put the chain on the correct side to link up to my differential hub properly (that's where my coaster sprocket is). Or is ~30" still plenty of room for mechanics and I am worrying over nothing? Just a point of reference--the rectangle with no uprights inside it yet is towards the rear of the velo, the one with the uprights with holes drilled in them is towards the front.