mattface 

The bike coop I work at has been asked to donate a trike to some special needs students. We don't have a trike, but we have someone who is eager to try to create something. I was looking over the Trike they have, and I think I've come up with an idea that is workable, but I still need to work out some of the details. Basically i would use 2 20" wheels with conventional hubs reamed out, and a solid axel run through each of them. 1 wheel would have a long solid axle connected to another hub. that hub would go into the original dropouts with a freewheel, and extend out the left side. Bith exels would bolt into an axel assembly that could be bolted onto the seat and chainstays. The maun thing I've not quite got figured out is how exactly to mount bearings into the assembly for the axles.

Anyway, I don't really want to reinvent the wheel. If someone has already come up with a good design to convert a regular bicycle into a trike using mostly used bike parts, and a few simple materials, I'd love to hear about it. So has anyone here seen this done, or seen plans for how to do it? Thanks for your help.

vpiuva

Haven't done this, but I would also look at recumbent trikes for inspiration

Wordbiker

You could either buy a trike kit or study it to pattern yours from.

mattface 

Thanks that is close to what I had in mind to build. It should offer good inspiration.

DMF 

Add a training wheel.