What's stopping the bamboo bike from shooting into the mainstream?
The panda jokes are now a long way from my mind. I'm standing astride a bike crafted from an armful of bamboo cane, about to push out into rush-hour traffic.
As a material for a bicycle frame, it makes more sense than it sounds. In Asian countries it's often used as scaffolding, and even to reinforce concrete, so it's certainly strong. But the important part is that it's also incredibly springy.
Next time you're on your bike, find somewhere away from traffic and look down at your frame when you set off. Most people don't realise that bikes are not rigid, they warp and bend slightly when you ride them. The largest of my bikes flexes so much when I corner hard that I can actually feel it distort underneath me.
As well as such practicality, bamboo offers sustainability – so long as it's done right. Some bamboo production is far from green, causing biodiversity problems and creating toxic dioxins from treatment with chlorine.
The cane used here, though, is reportedly grown responsibly in Taiwan's Yushan national park, and hand-picked before being shipped to bike manufacturer Calfee's California headquarters. It's also smoked and heat treated, rather than chemically hardened.
There are definite environmental benefits to using bamboo as a raw material: it grows extremely quickly, requires minimal pesticides and water and is a prolific producer of oxygen.
So, why not build bikes from it, rather than more energy-intensive steel or carbon?
Well, people have. In fact, look up English patent number 8274, filed in 1894, and you'll see that it's far from a new idea. It's just never taken off.
Craig Calfee intends to change all that. He was one of the early pioneers of carbon fibre bikes, and he's been experimenting with bamboo since 2005. He now builds high-end bamboo racing, mountain and cargo bikes, and is working on bringing cheap and simple utility bikes to Africa. Because of the climate there, the raw material grows well, and local people could be trained to produce the frames themselves.
It's one of Calfee's racing bikes I'm riding today, all £3,000 of it (available in the UK via Eco Age). Worryingly, it's incredibly light and looks fragile, but it does come with a 10-year guarantee.
So, what does it feel like to ride?
When you played with a bamboo cane as a child, and swished it through the air, it felt like energy incarnate. That's a little how this bike feels to ride.
When I first sprint off, nothing happens for a split second, just like when you swish that bamboo cane. Then, almost before you've noticed, it springs ahead as though it has more energy than you've put in. It rivals carbon, steel, anything I've ridden.
It's also comfortable. But not like a big, heavy commuter bike with large, bouncy tires. It just soaks up the bumps, with no lolling around.
The incredible part of this bike is that this feel comes from something that grows naturally – technically, it's a grass. It's simply harvested and crafted in a workshop. It's not a hi-tech carbon fibre bike which has been moulded, layered, glued, baked and finished. Even the joints are made of natural hemp.
But will it become the next big material for bike builders? In the developing world it makes perfect sense, but it will be a big task to oust carbon fibre in the west. It took almost a decade for riders to trust that material, and bamboo somehow feels even more alien than that did. Maybe everyone should have a test-ride on Calfee's bike.