The "uniframe" comes from the fact that the trike frame is also the seat frame and the only external frame parts are the cross memebr and boom.  I'll let you know if this actually works out or not :)  The frame was made from 1" EMT tubing and the cross member is made from 1" x .063" box tube.  It is a crossmember I had kicking around for a while which I notched a few times to not only give it a 15 degree kingpin inclination, but also sweep the wheels forward at a 15 degree angle.  I wanted to increase the wheelbase for stability and comfort, but in the end, the amount of extra work it took, compared to the gain, it wasn't worth it, so I shelved it . . . until now :)

     The front wheels are 16" wheels off an old jogger/stroller.  They are a hidden gem because they already come with ½" sealed bearings and are ready to take a ½" bolt for an axle.  It has bolt and bushing kingpins and will have a sliding boom for rider adjustment.  I'm hoping the frame will be strong enough to allow my daughter to ride it for at least a couple summers before she's too heavy for it.  The rear wheel is in pretty rough shape, but that will clean up fine, and it will have a single piece kid's crank to go along with the 5 speed freewheel.

     I like the simplicity of the frame, but it was a bit of a pain to get the bends lined up and aimed at the rear axle.  Right now, it's all ready to have the handle bars welded on and the arms to mount the BMX side pull rim brakes.  Next I'll add the tie rod and a short transverse section of tubing just in front of, and above, the rear wheel will to stiffen the rear end a little and provide a brake mount for later, if so desired.

22 July 2006

     Got a little busy with a few details on my Speed plus finishing up the Flying - V, so I didn't get a lot of work done, but I did make a little headway.  I got the outer boom tube lined up and welded on the crossmember so now all I need to do is notch the inner 1¼" square boom tube and weld the BB shell onto it.  The outer boom tube is a 1½" x .100" box steel tube with a 5" slit in the bottom and two connector nuts welded across the slit to take two pinch bolts.  The tie rod was made and attached with two ¼" rod ends and a piece of ½" SS tubing.  The seat was made from some gravel truck mesh with pockets sewn along the edge to accept ¼" AL rods to wrap the seat lacing around.  Much more simple, cheaper and faster than installing all those grommets, and a little lighter too.  The rear wheel is the same one from the two earlier pictures.  I tore it all apart, took a wire wheel to it, painted everything flat black and rebuilt it with new, unrusted nipples.  The freewheel body and gears are also painted and will be reinstalled and regreased.  It's starting to look like a trike and my daughter fits it well and likes it so far.

     The small yellow trike in the background is a kid's trike built by a prolific trike builder friend of mine named Larry.  My little ones take turns on it while they wait for me to finish up theirs.

13 Sept 2007

     The trike has been hanging a long time and I decided to pull it down and finally finish it up.  I added a piece of tubing just above and in front of the rear wheel for some extra stiffness.  I wasn't sure of the long term strength of the EMT tubing as my daughter grows, so I added salvaged MTB seat stays to each side for a little triangulation.  I finished up the handlebars and added the caliper mounts for rim brakes with Tektro levers and a locking lever as well.  The chain line is nice and simple and will run through a roller blade idler under the front seat.  I wanted to assemble it some more, but the paint is still a little tacky.  A flag holder is on the back left side.  Final pictures and details once the trike is fully assembled.

1 Oct 2007

      I didn't get the trike finished in time for the parade we went to, but I got it assembled afterwards and my daughter goes out and does a lot more riding with her brother and friends now, so the exercise is a good thing.

      The boom has lots of adjustment for her to grow, and the trike's rear end is nice and stiff, which was a concern with the EMT tubing comprising the major structural part of the frame.  I ran the rear derailleur cable through the frame rail and I'm starting to dig the clean lines the internal cables give a bent.  The only problem is it means lots of cable housing which also means more drag than I would like unless I buy top-end cables and housings.  It's more than sufficient for now, and she's very happy with it, but if I was to do it again, I'd add about 4" to the front of the seat rails to move the front wheels and handlebars a little further forward.  Below is a picture comparing it in size to Larry's trike and an adult sized trike.