It's pretty damned tough to find pictures of these things. What I'm planning to do is this; cut the top tube and downtube off the donor diamond frame where they connect to the seat tube, make a head tube out of 4' or so of EMT clamped to the seat tube(to be welded later, after I figure out if this will work), extend the top of the fork as much as necessary, and run a small-bike fork and 16" wheel in the front, and a 3-speed hub 26" wheel in the back. The handlebars will probably be above-seat, unlike the examples.
This is pretty much just an experiment, unless it rides well. In that case, I may just keep building these.
Your thoughts, suggestions, ideas are welcome.
How about installing a seat with some kind of a backrest. I think that could make it easier to ride, especially if it has under seat steering.
Please keep us posted how it goes.
Thanks, will do!
I'm about to take a hacksaw to the donor frame and see what I can do about the upper fork. As I can't duplicate the fork's threading, there will probably be a welded pipe extension involved, and I have access to a welder at my job.
I think Jim W of rodbikenkustom said you could get auto exhaust pipe in the same dian. as bikes.This lets you use the standard headsets.Cutting and welding in an extension to the steer tube should not be a problem.
Thanks to all for any ideas or tips.
I'm in the mockup stage, which is an impressive way of saying that I have all the parts leaned up against the fence and shimmed up with blocks of wood into the approximate position they'll need to be.
The front triangle has been cut away, and I was pleased to see that this frame is made of fairly stout tubing. Also, the rear triangle itself with 26" wheel is amazingly light.
I've found a headset in my parts box that is pretty close to fitting my custom headtube. The bearing cups are about 1/32" too small in diameter, but this is not that critical, and I'll find a way to improve the fit and have a stable headset.
The biggest obstacle right now seems to be the fork, oddly enough. I want the "Velocheeto" to be as close-coupled as possible, with headtube tight against the seattube, and the front wheel as close to the bottom bracket as possible. This is proving to be difficult with the 16" front, and the rear triangle set perfectly level for appearances' sake. A 12" front and a child's bike fork would be much easier to use. As I have the 16" front and bmx and cruiser forks, I'll have to do something creative to make it work. I'll reinstall the cranks to establish clearance needs, then whomp something up.
As it stands, my fork/wheel combination will not allow me to have the head tube directly abutting the seat tube with the rear triangle set level. The chainring and pedals are the interference points. I don't want to be stubborn about it, but it just seems to be both simpler and stronger to do it this way, and I can just see it completed in my mind, can feel how it would ride.
I'll cast around for a smaller wheel/fork tomorrow after work. Maybe do some brainstorming and sketching on my break. If I can't come up with something, the next step will be to rework the frame.
As it stands, I've resorted to using a front triangle from a baby bike, mounted quite low. This is counter to what I'd intended, namely to use a small wheel almost directly under the bottom bracket. I'll have to weld it this weekend. I'm thinking about a wheel from an inline skate or razor, but it's just too small.
This needs a lot more thought.