Hello, I'm Ron Covell. Many years ago, I had
the pleasure to work with a gifted young designer named Spencer Owyang. I helped to build a prototype for his cutting-edge bicycle design, called the
Monolith. This was in the early days of suspension bikes, and Spencer had some
revolutionary ideas. One of the key design elements is the curved large
diameter tubing used for the top tube and down tube.
I have the task of creating
the vertical component, which holds the bottom bracket, the rear suspension pivot,
the rear shock, and the seat post, which is a monocoque construction. The term
"monocoque" means single shell, and like an eggshell, these thin walled, hollow
sections are very light and extremely strong. I made these components by shaping aluminum sheet over simple hammer forms. Using Spencer's full size drawings, I
made the hammer forms from medium density fiberboard. I glued two
pieces of 3/4 inch stock together, then I cut out the profile, making the forms one
material thickness undersized all around, and the edges were rounded to the
proper contours.
I was able to use an edge rounding bit on a router for some of the shaping, but the tapered seat curves had to be
carefully hand shaped. The hammer form, the aluminum sheet, and the clamping block
are assembled and clamped tightly together. I used the wooden mallet to
carefully form the aluminum sheet against the hammer forms. I designed the form so they could be used for both the right and left side
pieces, and the parts were made oversized so the portion with the holes for the
alignment pins could be trimmed off later. Once the parts are formed and trimmed, they're welded
together and the welds are smoothed. Everything is made from 6061 aluminum,
and the frames are heat treated after welding to bring everything up to the t6 temper. And here are the preformed parts for the
monocoque portion of the frame. In the next video, I'll show how a tube rolling
machine is used to curve the top tube and the down tube.
Then I'll use a frame jig to help trim and align all the components for the main triangle, and
I'll weld the frame together..