Here are a few pictures of my first attempt at building a bicycle.
The plan is to build two long wheelbase recumbent bikes, and add some crossbars to join them as a sociable (side-by-side) quadracycle. I'm on a bit of a tight deadline, as I hope to have it done in time for RAGBRAI, which begins on July 19.
Why build a quad sociable? Well, Marilyn doesn't like the never-changing view from the back of a tandem, so I hope that having a bike with side-by-side seating will be something we'll use more often than the tandem. A quad might also be a good platform to eventually add a fairing, which would make riding more pleasant when there's a chance of rain or snow. But the immediate motivation is to have something comfortable for the weeklong RAGBRAI ride, with a nice, wide seat for my nice, wide rear-end. You can buy quad sociables from places like Lightfoot Cycles, but I'm on a tight budget this year. So I'm trying to put something together quickly by scrounging landfills, dumpsters and craigslist, and doing a little welding.
I started by buying two books by Brad Graham and Kathy McGowan: Atomic Zombie's Bicycle Builder's Bonanza and Bike, Scooter, and Chopper Projects for the Evil Genius. They also maintain a website with a builder's forum.
My first bike uses the rear suspension triangle from a rusty NEXT PowerX 26" mountain bike frame I found at the Iowa City Landfill. A little grease was enough to get the suspension moving, but it has a one-piece crank and rusty steel wheels, so I will be using the wheels, brakes and bottom bracket from a nice Giant Acapulco bike I also found there. It's almost too nice to chop up, but it had to be done. The front fork and wheel is from a 20" Mongoose Hoop-D stunt bike I obtained through craigslist for $25.
Here is a picture with the bare frame with both wheels (the boat seat was just placed there so I could figure out where to put the bottom bracket):
The front of the main boom is about 12" from the top to the ground, and the rear suspension joint is about 14" from the ground. Hopefully that will make for a straight chain run passing near the suspension pivot, with the goal of minimizing pedal-induced suspension movement.
Here are the suspension mounting tabs tack-welded into place. I used the suspension as a guide to align them, but dithered too long trying to get a bead going on the 1/8" thick metal, and the plastic suspension bushings started to melt a bit.