With the exceptions of wood and bamboo, bicycle frames usually aren't made from sustainable resources. And although some programs do exist, we generally don't think of old bike frames getting recycled. Italian design studio Eurocompositi is setting out to change that, however, with its 3D-printed Bhulk mountain bike frame.
The end product of the company's Aenimal project, the proof-of-concept frame is made of polylactic acid (PLA) using fused deposition modeling (FDM) – that's the type of 3D printing in which objects are built up a layer at a time, from a molten polymer.
PLA is itself a biopolymer, made from plant sources such as corn or sugarcane. Not only can discarded PLA products be melted down and made into new items, but because the material is biodegradable, they can also simply be composted.
Although it does still require energy to produce PLA filaments and then use them in a 3D printer, Eurocompositi claims that it requires less megajoules per kilogram of material than is required for other commonly-used polymers such as ABS or PET. Additionally, the Aenimal production facility is reportedly solar-powered.
As can be seen in the images, the frame is made from individually-printed components that are then slotted/bonded together. And as for how well such a frame holds up to real-world use, the company simply states, "The knowledge and experience of the Eurocompositi team have been fundamental to design the right tube shapes and dimensions, in order to maintain a certain stiffness and durability with a material that surely doesn’t have the mechanical characteristics of the most advanced composite materials."
The design team won a gold award for the Aenimal Bhulk, at last week's Eurobike show in Germany. There's no word on when or if it might reach commercial production.