fab bike : Bicycle Rapid Prototyping and Integrated Sensing
Traditional welded metal bicycle frames require expensive and massive tooling in order to fixture the parts before welding. Even then, the stress introduced by the welding process often results in frames than need to be bent back into alignment after they have been removed from the tool. Conventional fiber composite bicycle frames are very expensive, also due to the processes used.
The 'fab bike' frame is laser cut in panels from cardboard, then stitched together into the three dimensional shape, like papercraft. With geometric optimization in the design process, this final shape is more straight and true than the typical welded frame after welding. Pre-cut holes can precisely align hardware inserts, then the whole thing can then be covered in fiber composite by traditional wet layup methods. Throughout the construction process, zero non-integral tooling or formwork needs to be produced or used. The final result is well aligned, lighter weight than most commuter bicycles, and fun to ride!
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The 'frame sense' frame employs structural carbon fiber for strain sensing, allowing the bicycle frame itself to act both as a power output meter for the rider, and as a structural health monitoring device, capable of determining if the frame has been structurally compromised.