A group of researchers have reinvented the wheel—and named it for a city in Denmark. Dubbed the Copenhagen Wheel, this striking motorized unit converts your bicycle into an electric hybrid, making it easier to ride longer distances. It grew out of a partnership between MIT’s SENSEable City Lab (which explores how sensors and mobile devices impact cities) and Copenhagen (where 36% of citizens traverse the nearly 400 kilometers of bike lanes daily).
"It started as a class assignment in spring of 2008, and a dedicated team took over in 2009. The main motivation was to make cycling a competitive alternative to car travel and public transport, while preserving the pleasures of normal cycling," says Assaf Biderman, associate director of the lab, co-inventor of the wheel with Carlo Ratti, and CEO of Superpedestrian, the company he formed to bring it to market under an exclusive license.
With its brains hidden behind a slick red disc, the wheel looks deceptively simple. But it works hard so riders don't have to. Powered in part by a rechargeable 48-volt lithium battery, the 350-watt motor gives riders a top speed of 20 mph for 31 miles in standard mode, and works in all weather conditions. But it’s the other power source that sets the Copenhagen Wheel apart. "You ride it just like a standard bicycle, and it captures energy when braking and cycling to supplement you with around three times the power of a normal cyclist, when you need it," Biderman explains. "The integration between your motion as a rider and the motor's added power is like a synchronized tango; hills disappear and distances shrink. You almost forget the motor is there. The effect is quite magical."
That hocus-pocus is why the world was excited when the prototype surfaced in 2009. It racked up honors, including both the Green Award and the Green Dot ward for inspired eco-friendly transportation, and the prestigious James Dyson Award for outstanding student design. Excitement was high; the lab was receiving daily emails from around the world asking when it would be available.
And then the news stopped. For three years, there wasn't more than a peep out of the team. The fame was cool, but they had their heads down, refining the wheel so it could fulfill its early promise. "The technology for the Copenhagen Wheel was under development for over three years at MIT, where some of the key design and engineering challenges were addressed," Biderman explains. "We added an embedded control system that will enable the motor to seamlessly interface with the rider's motion without requiring any input from the rider, except pedaling. And we upped the power and gave it an optimal range so that it could addresses the mobility needs of the majority of city and suburban residents, while keeping it lightweight and elegantly designed."
Another key update was the addition of a multifaceted mobile app. It tracks rider stats (time, distance, calories burned), automatically locks the bike when the owner walks away (and unlocks it on approach), taps into the cloud to provide safe biking routes and real-time road condition data, and even allows for remote diagnostics. "We pioneered the integration between mobile phones and bicycles, which opened the door to a vast array of services and user developed augmentations," Biderman says. "You can use the app to choose from a variety of modes, such as exercise mode, where you constantly charge your batteries while exerting effort; turbo mode, which gives a super boost; eco mode, which extends your range by optimizing the amount of energy used to propel your ride; and my favorite mode, called flatten my city, which feels as if you’re riding on a plane, providing power assist uphill and regenerative breaking downhill, so they both feel equally easy."
Biderman founded Superpedestrian about a year ago, when the technology was mature enough to bring to market. Preorders for the $699 easy-to-install Copenhagen Wheel—no wires or external batteries required, so it's simple to retrofit your current bike—began this month, and units will ship this spring. The current limited edition version fits 26" and 700C size rims. Enhancements in the pipeline include a 20" option, more speed options, and an increase in processing power.
Who knew the wheel was ready for an upgrade?