Steve's Recumbent Archives

Ron H's Homebuilt Short-Wheelbase Wood Recumbent - 2/2003

Wood Box-Structure Frame
Completed Bike

When I built the red bike I had plans for a design built the usual way with metal tubing but didn’t want to get into welding and all that.  Then I saw Steve’s bike on the web and the lights suddenly went on. 

I had already started collecting yard sale bikes to experiment on so I cut the rear triangle off an old 26 inch street bike, a bottom bracket shell and partial seat tube from another, and the head tube with forks off an old BMX bike.  I  laid them down on an old sheet of ¾ in. Plywood in the position and angle of the plans and just drew lines between them in what looked like a sturdy enough wooden frame that would overlap the tubing.  Once it was cut out I flipped it, traced it and cut out another one.  After that I used my drill and one inch drum sander to carve out half circular grooves in both forms to hold the tubing, and bolted them together with the bike parts sandwiched inside.  I made the seat out of two small sheets of ¼ in. ply covered with foam and naugahyde.  That’s the short version.
Like I said the whole thing is bolted together.  There’s a short section of bottom tube on the rear triangle and short sections of top and bottom tubing left on the head tube.  All three have bolts through them to keep the wood together and the bike parts straight.  It came out kind of heavy with the solid wood, cheap frames, and about six bolts.  I changed the seat several times and finally cut the frame down to recline it more.
It rode really nice.  I was surprised since I really kind of “winged” it but I had managed to get the geometry just right in spite of everything.  It had only twelve speeds and old center pull brakes  but I started riding it to work in the spring (about 26 miles round trip) and enjoyed it immensely.  I’d commuted on a bike for about twenty years and was about to give it up because of aches and pains when I discovered recumbents.  The red bike was a revelation.  It was fun again.

After a few weeks I added a higher back rest on the seat and a red choroplast windshield ­a kind of half fairing- and what a difference it made.  It was slow up the hills but just flew down them and I never went unnoticed by motorists.
So, after a year of bombing around town on “that weird red bike” as it was called, I decided to try a SWB version and actually do some design work on it.  It turned out even better.  A wood working friend of mine told me that a hollow box would be just as strong as the sold slabs of wood so I designed the new bike body to be made out of four layers of ½ in., ply with the two inner layers cut out to make hollow spaces.  The first picture shows the opposite sides glued together.
The seat is more elaborate with four sections of padded ¼ in ply glued to two ¾ in rails.  It slides down over the body and attaches with a bolt and wing nut.  I found a really nice chrome-moly mountain bike frame at the dump to use and this time cut the seat stays off and through-bolted them to the body.  I  bought the front forks brand new with bosses for V brakes.  The whole thing is epoxy glued with no bolts this time except for the seat, seat stays, and idler wheels.  I made the tilt back steering column from small parts and the handle bars are cut out of an old baby swing.  As you can see from the pictures it’s as unusual looking as the red bike but it’s lots more comfortable, more maneuverable, and a blast to ride.
One thing to mention;  I made the yellow bike out of the ½ in ply because I was afraid that thinner stock wouldn’t have been strong enough to withstand the torque of pedaling.  On a LWB it doesn’t matter so much but on a SWB the crank is out there on it’s own, so to speak.   It turned out more than strong enough and I realize now that I could have used ¾ in ply for the inner two layers cutting them out and leaving only an inch around the outside and around the grooves for the tubing, and then using ¼ in for the outside of the box.  As long as the outside seams were completely glued and sealed the box would still have been plenty strong and been lighter at that.  The slanted “windows” in the body were an attempt at lightening but could probably be made larger as well.

Ron H. February, 2003

Ron H's Homebuilt Wood Recumbent - 1/2000

Ron on the bike!  "I don't think the bike looks too bad for something that I basically winged.  I probably really lucked out.  I'm thinking in terms of a SWB model next so that I'll have some experience with both types before I spend real money on building my final commuting machine.  Right now though I'm having fun just building bikes out of junk.  Just this morning I found an old huffy at the dump that has a great looking headset and front forks. Sometimes things just fall into place." - Ron H.,  2000

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