E.M.Unit - U.S.A.: 2012

June 15, 2012

ICW Full Suspension

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.

On Road Oddities

A few strange findings in my travels...

Kitcar?

Not so strange.

Even dragons need to commute to work.

Burned out Mercedes.

June 12, 2012

Carbon Fiber Flat Bottom Kart

Sometime ago a friend of mine was racing karts competitively. Taking cues from the flat bottom trend in automobile racing I came up with a way to create a flat bottom pan for his kart.

Made of carbon fiber, kevlar and fiberglass matt it was tested in secrecy during a race practice session.

The image below shows the melamine mould from the first version of the floor pan.

The 'wings' under the front a-arms (as seen in the original mould) were eventually cut away and the flat front section was added.

The section under the side pods was made of abs sheet. You can see the difference in the reflectivity of the two materials in the shot below.

Throughout the practice session he would pull in to the pits and we would raise and lower different parts of the pan to see if any type of downforce could be gained. By lowering the front and raising the rear the pan would create a dead air space under the kart forcing the air over the top of the chassis. This would produce pronounced downforce that allowed the driver to enter the corners at a higher speed.

In order to free the rear of the kart we cut lifts in the area between the rear wheels and the back end of the tube frame.

All in all the experiment was considered a success even though the legality of the whole idea was a bit questionable.

A shot of the foot pedal area and pan from above. This area was typically closed in by an aluminum pan that ended under the seat about mid chassis.

A top down shot of the front wheel and brake cutout.

The best part is nobody really noticed the giant pan and the pictures of the bottom were snapped quickly in the pits so it's top secret-ness would be preserved.

In addition to the flat bottomed floor pan I also created a carbon fiber and kevlar chain guard to prevent a broken chain from being spit into the back and shoulder of the driver. Typically the chain is unprotected and is thrown free when it snaps. The guard was designed to be a replacement item yet during testing it proved to be nearly bulletproof.

It is the yellow item in the image below.