Carbon fiber bike frames have been around for quite a few years. Cyclists who prefer them often cite the fact that they are lighter than their aluminum counterparts. They are also stronger, but more rigid at the same time. So there are trade-offs. The question is, can a carbon fiber bike frame be made better? Apparently it can.
Franco Bicycles, a California company specializing in custom bike designs, contracted with Arevo to create a system for 3D printing single-piece carbon fiber bike frames. The technology company’s first bike frame debuted in 2018 to great reviews. Arevo is now ready to begin ramping up production for a line of Franco bikes that will be sold under the Emory brand.
Single-Piece Construction
The big selling point here is the new bike frame’s single-piece construction. Nearly every other carbon fiber bike frame is made of a number of components that are fabricated separately and then glued together. The system works well enough, but there are obvious stress points where the components join.
Single-piece construction eliminates the stress points. In theory, that means a stronger bike frame capable of standing up to more severe punishment. Whether or not it makes the bike frame more rigid at the same time remains to be seen.
Another plus is the frame’s void-free construction. By using a continuous fiber placement 3D printing method, the layers of carbon fiber that make up the bike frame are laid directly on top of one another on-the-fly. This creates a finished product that does not have air pockets or other voids within the plastic material.
This is a substantial improvement over traditional carbon fiber frames that may have small voids. Void-free construction reduces the risk of catastrophic failure resulting from small cracks or voids capable of getting worse over time.
Faster Production
If all that is not enough to convince bike makers to switch to single-piece frames, Arevo claims their 3D printing process reduces production time from several months to just a few days. They say they are capable of pushing out larger volumes with significantly less labor and, as a result, less expense too. This should theoretically make for a cheaper bike frame as well.
Rock West explains that it is all in the 3D printing process. Traditional carbon fiber bike frames have to be fabricated and assembled manually. It is a protracted process that takes a lot of manhours to complete. With 3D printing, the process is virtually automatic once the printer is started.
Printing carbon fiber parts with a 3D printer involves combining carbon fiber thread with resin using a specialized dual printhead that accepts the two materials separately but combines them as they are laid down. Once printing begins, the machine lays down one layer of carbon fiber after another in one continuous stream. The material hardens in place so there is no need for vacuum bagging and autoclaves.
The Future of Carbon Fiber
Creating a single piece carbon fiber bike frame is a great breakthrough for Arevo. However, the implications of what they have done run far deeper than making cycling better. The company has greatly advanced the prospects of transforming carbon fiber fabricating from a manual process to an automated 3D printing process.
Some in the composites industry have been speculating for quite a while that 3D printing is the future of carbon fiber. This new bike frame is testament to that. Not every carbon fiber part will be 3D printed in the future, but many will be. That will make them cheaper, more accessible, and open the greater customization.