Extraordinary Grass

An ancient weed anticipates the technological future.*

For the opening race of the Eastern collegiate cycling season, Nick Frey, a junior at Princeton, had a brand new bike. Frey, currently the under-23 national time trial champion and a recent hire of the Time Pro Cycling Team, rides the finest carbon fiber technology packaged in a $13,000 team bike. But he had left that bike at home. What he had brought instead—and what was drawing a steady crowd of disbelieving collegiate cyclists on that chilly March morning—was a piece of even more recent technology: a racing bike he and his friends had made themselves out of bamboo.

By look and feel, it resembled a kind of exotic wood. By weight, it could be mistaken for another top-of-the-line carbon or titanium bike. But one ride and the racer would know that it couldn’t possibly be either—because it was somehow both.

All bikes strike a balance between two contradictory aims: stiffness, which translates into greater efficiency, and vibration dampening, which gives a smoother ride. Aluminum is stiff but rides, too, like a rod; steel bikes are the most fluid but less responsive, not to mention heavy. To date, carbon fiber has been the industry’s best compromise: pioneered by California bike designer Craig Calfee, it wins the stiffness competition outright, yet remains remarkably compliant.

Then Calfee himself made another discovery: bamboo is just as stiff as carbon fiber, and, owing to its fiber content, four times better at absorbing shock.

When Frey and three fellow engineering students set out to improve on Calfee’s design, Frey used training rides as bike tests. With their first prototype, he reported in his blog: “The ride quality is simply incredible. It is very stiff for climbing and sprinting…and the fatigue I usually have at the end of a ride was just not there.” This is why Calfee’s bamboo bike has seen its first popularity among ultra-endurance triathletes, who follow a 112-mile bike ride with a marathon run in Ironman competitions. Riding a bamboo bike, says Frey, “is like wearing comfortable loafers and having the efficiency of track spikes.”

The other benefit of bamboo strength in a bike is best appreciated by amateurs: unlike carbon fiber, bamboo can take a few hits. A carbon bike’s extraordinary stiffness only exists on one plane: that of the bike upright and moving forward. To minimize weight, the tubes are so thin that any force applied against the direction of the bike can crack the frame. “It’s incredibly common to break carbon bikes,” says Frey, “You take one fall and you’re out.” Bamboo was strong before it was a bike, with a naturally lightweight structure. So you can both power it forward and, as Calfee did with a cargo bike he designed for rural communities in Ghana, saddle it with 100 kilos of cement.

There’s strong, and then there’s bamboo-strong. The paradoxical nature of bamboo’s strength reflects the duality of the plant itself. It resembles a reedy tree and readily stands in for timber, but with its rhizome root structure, bamboo is actually a grass. Its strength belies its flexibility, and its flexibility belies its strength. In fact, bamboo’s strength comes not at the expense of flexibility but from it. In the West, understanding this means shifting into a new bamboo paradigm. “Our concept of strength is, it doesn’t move, it doesn’t break,” says Dan Smith, who owns Smith & Fong, the largest manufacturer of bamboo plywood in the country. “The Chinese concept is, you’ve got to bend with things. If you don’t bend, you break. Bamboo’s strength is in its ability to bend. And that’s the miracle.”

Bamboo has greater tensile strength—or resistance to being pulled apart—than steel. It withstands compression better than concrete. The proof is in the way it grows: up to 180 feet but only as wide as a foot in diameter. All the strength needed to hold up its own height is concentrated in that base, which is no wider than the very tip of the stalk. At the same time, against strong winds, something that tall can do only one thing to survive: bend.

Smith & Fong, which first cracked open the bamboo flooring and plywood markets in the United States in the early 1990s, is now engineering gymnasium floors and bamboo structural beams. Structural application, says Smith, is simply “an expression of bamboo’s superior qualities.” Environmentalist architect Michael McDonough strongly advocates bamboo as a superior alternative to steel in reinforced concrete. The production of steel, he says, is one of the greatest contributions t0 ozone-depletion. As countries industrialize, “if you can grow the steel in your backyard, then you don’t have to produce it, you don’t have to ship it.”

As a sustainable building material, bamboo is—as always—completely counterintuitive. It’s “the one material where the more you used it, the better things got,” says McDonough. It sets the record even for grass-speed growth—in some conditions well over a meter a day. As it grows, it produces 35% more oxygen from carbon dioxide than trees and more effectively binds soil to prevent erosion. Once treated—by extremely diluted hydrogen peroxide or by smoking, like smoked meat—it’ll last; engineered into plywood, furniture, bikes, or concrete, it keeps its lifetime’s worth of sequestered carbon dioxide out of the atmosphere.

McDonough’s pioneering efforts in sustainable housing, e-House and ArcHouse, have kept pace with developing bamboo technology. E-House has all bamboo floors and cabinetry, among other innovations like aerated concrete exteriors and solar-heated water. ArcHouse, a modular home, has an engineered bamboo exterior: two panels of bamboo oriented strandboard—a compression of bamboo strips cross-laid for strength—insulated with foam made from the oil of discarded orange peels. Structural insulated panels are four times more efficient than their thermal equivalent of 12-inch thick wood exteriors while using a quarter of the material; McDonough estimates that they reduce energy consumption in a house anywhere from 50 to 90 percent. McDonough believes that bamboo’s natural sustainability paired with its engineered sustainability has the potential to remake the world.

Until now, however, bamboo perception in the West has been confused, and distorted by skepticism within the green movement itself. If bamboo was a grass—practically a weed—wouldn’t cultivating it displace real trees? If bamboo was to be used as a tree, why wasn’t it certified for sustainable harvesting like trees? But bamboo’s own dual nature presented an obstacle for certification: the Forest Stewardship Council, the organization that presides over sustainable forestry, got stalled with bamboo because the FSC definition of “forest” meant trees.

It was up to bamboo to bend, and Smith & Fong did. With the agreement that bamboo forests would follow the same rules as conventional forests, FSC finally certified the industry’s standard-bearer, seven years after Smith began trying to apply. Recently, the United States Green Building Council began to award the use of bamboo in building with a credit toward its own LEED certification (Leadership in Energy and Environmental Design).

McDonough’s vision for bamboo is as a material perfected by science: rather than making “fancy Gilligan’s Island huts” straight from bamboo stalks, he wants to put bamboo “through an appropriate industrial process. And then it can last 400 years.” Which means 400 years of sequestered carbon. Yet, the bike is proof that this “dinosaur grass” is somehow a few steps ahead of our technology. It’s hard not to marvel at Nick Frey’s Time bike and its precisely tuned oval tubes, optimized for power transfer from the pedals—until Frey points out that his bamboo bike is exactly the same. “See how this is curved?” he says, pointing to the rear triangle of the Time VXR. He grins. “Ours are curved.” Except that Frey and his new bike company didn’t make it that way. On the edge of the bamboo grove, the wind had pre-tuned the poles.

–Lily Huang

*This story was published in another form in Newsweek.

Visit Nick Frey’s new bamboo bike company, Sol Cycles.