CAD, or computer aided design, is a term thrown around a lot, so I thought it pertinent to dive into what CAD design is, and why it is so important when it comes to making Argonaut bicycles. One of the primary reasons that the look of a bicycle has evolved from relatively straightforward, two triangles with round tubes, design to the wild, swoopy, flowy surfaces we see now is the broader industry’s move from metal to carbon fiber frames.
’96 GT track bike by Cycling Tips
James Huang’s article about the design of the GT superbike
The fact that carbon cannot be welded like metal tubing requires that the frame be made in an alternative way. It is possible to glue round carbon tubes together and reinforce the joint areas with additional carbon. However, it is more common that sub-sections of the frame are molded in a halved metal cavity and bonded together. In order to create the mold that makes an individual frame part, like the front triangle or just the head tube portion of a bike, a computer model of the finished part needs to be created. That computer model, or CAD design, is then used to create the metal cavity, or mold. Frame molds are often referred to as frame tooling.
CAD Model of a Head Tube.
Head Tube out of the computer and in the tooling.
Good computer aided design is really the most important part of the whole carbon fiber bicycle manufacturing process. Not only does it control the final aesthetic of the bike, but there is such a thing as good CAD and bad CAD. A bad CAD file ends up being a nightmare to work with. If the designer doesn’t properly blend the surfaces or builds the model poorly, the drawing will crash or be unreadable to the program that runs the CNC machine. And that’s just the usability side. Just as detrimental is CAD design that fails to be aesthetically pleasing.
The Argonaut road frame was originally designed by Zach Hilbourne at Utensile in Portland, OR. I spent many hours working with Zach to refine the design of the frame – Zack patiently letting me poke at his computer screen and making errant hand gestures like a spastic kid pretending to be an orchestra composer. I’m proud of the design we landed on, but it wouldn’t have been possible without his excellent CAD design skills.
Thanks for reading!