> max egan
the great grass
not long ago, using an inkjet printer and a carefully cultured batch of cells, scientists at Wake Forest University grew a mouse heart on a piece of paper. A printer, just like the one in your office, on paper, just like what you’re holding in your hands now, and cells, just like the ones that are sitting in your marrow. It’s so simple as to be astonishing, but its impact in the world of medicine is unprecedented and nothing short of revolutionary.
Now, no one would suggest that turning this model to bike frame material carries an equal weight of discovery, but that doesn’t mean it’s not waaay cool. While great strides are being made in the metallurgical field and with carbon technology in large processing plants, in far away locations, it’s easy to forget the possi- bilities that can literally pop right out of the ground under our own feet.
Long a resource in the development of human culture, bamboo’s presence in our world has only grown from its uses in China over 7,000 years ago. The first paper was made with this stuff. Armies marched with it in their bows, their arrows, their spears, their knives. Peasants built houses with it, just as emperors did with palaces. Through millennia, bamboo was used for boats, carpet, furniture, bedding,
fishing rods, buckets, cups, musical instru- ments, and pipes. It’s eaten, taken as medi- cine, trod on as flooring, and threaded into our clothes. Bamboo even had a stake in the origins of carbon fiber: the first filament used in the light bulb was a thin strand of bamboo. In the search to find a filament that was a more efficient conductor of heat, carbon fiber was created from rayon in the 1950s (see Bionics, issue #8). It can grow 12 inches a day and reach heights of almost 120 feet. It can be harvested every 1 to 6 years and can yield 25 times more wood per acre than our northern North American hardwood forests.
But bikes? Fifteen years ago, Craig Calfee, of Calfee Designs in Santa Cruz, California was playing fetch with his dog. Instead of a stick, he was tossing a piece of bamboo he had picked up from a small clump growing nearby. His dog was relentless on this bamboo fragment, as most black labs are with any stick tossed their way. But every time the dog brought the bamboo back, it was in perfect shape: no fracturing, no splitting, not even any
scratching. If bamboo could hold up to the pressure per square inch of the canine jaw, Calfee reasoned it may hold up under cycling-specific stresses. He went straight into research and design mode, the start of a ten-year stretch to eventually bring bamboo to the high-end cycling market as a viable performance frame material.
What he discovered tested the industry’s fidelity to standard frame materials like steel, aluminum, titanium, and carbon fiber. Bamboo’s hollow structure and fiber alignment have a natural high-tensile flexural strength (also known as modulus of rupture or bend strength, a mate- rial’s ability to resist deformation under load) and rigidity. These fibers run longitudinally and are integrated in a matrix of lignin, essentially a woody organic polymer. If this sounds suspiciously like a naturally occurring corollary to another extremely popular frame material, that’s no accident.
photo by calfee designs