The history about how this project came to be is worthy of a post of its own so I will not go into the specifics of the frame fixture or the other frames that were made prior to this one.
I built my first bicycle (a lwb recumbent) when I was 17 and entered into this project when I was 25. I had no previous machining or professional bicycle building experience apart from a little metal working experience from prior motorcycle projects.
The name of the undertaking was "Inspiration Cycle Works" and it was truly an inspired event.
Everything to make this frame was created with care and precision in a small garage shop by three people.
This is my self designed fully suspended custom built mountain bike frame.
The frame is made from thin wall, TruTemper, high strength, double butted, CroMo tubing, and it is TIG welded at the tube connections and brazed at the flat plates.
The early stages of design:
An early idea and the only part of the whole process that was drawn on a computer.
Early idea evolving.
Another idea.
"Napkin" sketch of final frame configuration.
There is a funny story on how the final design came to be. I was having trouble mitering one particular tube. After three tries (at the last second the edge would fold into the end mill) I had to rethink the cut and decided to pass one tube straight through the other and avoid the miter all together. It was one of those 'ah ha' moments where the redesign turned out to be more elegant than the original idea.
Sketching of rear triangle.
Mitered tubes on full size drawing (hand drawn, yep, good ol pencil on paper).
Close up of tube thru tube detail.
Front triangle on tacking fixture.
I designed the tacking fixture from scratch without ever seeing any of the industry produced fixtures. Note this was prior to easily available design resourcing on the internet. Due to the nature of the frames the fixture had to be completely adjustable.
The fixture could handle a frame as small as a bmx to as large as a tandem.
It was easily configured to tack up the full suspension frame and rear triangle together.
The entire fixture was sketched on graph paper and produced on a Allied mill and Atlas lathe. But more on that in another post.
Fixture, frame with technical drawing above.
Front triangle in a tube vise.
Below the head tube you can see the custom made chain and seat stay fixtures.
Cable routing sketches:
Overview.
Side view.
Top view.
The finished bicycle.
Side view.
Back 3/4 view.
Another side view.
