Taking the Copenhagen Wheel for a Spin in Cambridge

Xconomy Boston — 

I’ve long been a bicycle commuter. And with the rise of urban bike-share programs, many more people are finding the benefits of biking, both for individuals and cities. More bikes on the road means less car congestion and less pollution, and it’s a good way to get exercise.

But what if biking to work or school is just too far or hilly? That’s where Superpedestrian wants to come in. The MIT spin-out is commercializing the Copenhagen Wheel, a back bicycle wheel equipped with an electric motor. The wheel, which comes with a tire, is designed to replace an existing rear wheel and should fit most, but not all, bikes. It won’t do the work for you, but it will assist your pedaling and perhaps make that commute or workout less daunting and more enjoyable.

I took a bike with a prototype wheel for a ride to get a feel for the electric-assist. My spin near the company’s Cambridge offices was an eye-opening experience and lots of fun. I left thinking how this electric bike is really a smart bike and about the role sensor-packed bikes could play in cities in the future.

The company’s office looks like a typical startup, with desks filled with computers and engineers, except there’s a bike rack in the entry way and a work shop in back. The shop has the sorts of industrial tools need to make new hardware, including an industrial lathe and a 3D printer for quick prototyping.

The roots of the Copenhagen Wheel are in MIT’s Senseable City Lab, which developed the wheel for the 2009 United States Climate Conference at the request of city leaders. Even though prototypes have been around since then, only Superpedestrian, which raised $4 million in September, has a license to commercialize the technology.

Most electric bikes have battery packs that connect to an electric motor to turn the rear wheel. The Copenhagen Wheel has everything enclosed in a circular red hub that’s about half the diameter of a full wheel. The spokes connect to that inner wheel, rather than the bike’s original hub.

Inside the wheel is both the motor and batteries. What makes it a smart bike is the twelve sensors inside, such as an accelerometer—the type used on a smart phone—to sense when you’re biking up hill. That tells the motor to ramp up the power it delivers, lightening the load for the cyclist. Indeed, the core intellectual property at the company, which employs a number of robotics engineers, is the control system, which is designed to adjust power to the road and learn an individual’s pedaling style.

The bike comes with an app that, at this point, is fairly simple. It lets you chose among different modes—eco, standard, and turbo. You can also track your battery charge and miles. The company is working on an API and software development kit to let outside developers use the data from the bike in different ways, such as tying in bike workouts to fitness apps.

But once you start to aggregate the data, you can imagine how bikes become one more sensor on a city-wide network. Superpedestrian could learn common biking routes and give city planners valuable information, such as the location of potholes, using the hub’s accelerometer and smartphone GPS.

Moments after returning from my ride, engineers were able to pull up a small pile of data on it, which was remarkable. They showed me where I went on a map, the changes in speed, battery charge, and a long list of other technical data. Most of the log data is obscure but one could imagine apps that provided daily, weekly, or monthly recaps of your rides, or perhaps tell you where other Superpedestrian riders were.

Regen, baby

So what’s it like to ride? In a word, fun. With the electric assist, you only need a few pumps of the pedals to get to 20 miles per hour (the app has a speedometer; your smartphone mounts on the handlebar). That acceleration is a big advantage if you’re pulling out into traffic to take a left turn or need to pull around a bus stopping to pick up passengers.

But the designers of the Copenhagen Wheel aren’t trying to build an electric moped or scooter. In fact, getting above 20 miles per hour was difficult to sustain because the motor is limited at that speed for regulatory reasons. Beyond 20 mph, it becomes a different class of vehicle.

Superpedestrian officeAn intriguing aspect to the electric drive is the regenerative braking. Just like a hybrid car, the hub’s motor can recharge while slowing down or braking. (Essentially, the motor is running backwards and converting motion into electricity.) I think this will be a feature riders will quickly get used to and enjoy.

On the prototype I rode, I pedaled backwards to have the regenerative braking kick in. The regen was fairly powerful and it slowed me down substantially during my ten-minute ride, almost as if I was downshifting a manual transmission car. How this shows up in the final product is still being worked on, says Andrew Schmidt from Superpedestrian. The transition from biking full-on to coasting was a little choppy, but Schmidt says that, too, is something they’re still fine tuning.

As for cost, at $799 the Copenhagen Wheel is less than many electric bikes but more than most conversion kits. Its chief selling point is really the design: As an enclosed device, it’s simple to install and, as long as the wheel is locked, could be left on city streets. And having an accompanying app will be appealing to anyone who’s interested in tracking their movements and exercise.

It will come for fixed-gear and multiple-speed bikes. First shipments are expected at the end of the year. The replacement wheel weighs about 13 pounds, noticeably more than a regular wheel. The range will depend on the type of riding but the battery will need to be recharged about every 30 miles, Schmidt says.

Ultimately, what’s most compelling to me is that the Copenhagen Wheel could make the city smaller and biking accessible to more people. Instead of replacing the bicycle, it’s just making it smarter, starting with the rear wheel.

By posting a comment, you agree to our terms and conditions.

31 responses to “Taking the Copenhagen Wheel for a Spin in Cambridge”

  1. Bubba Nicholson says:

    Maybe you should just stop between biking and coasting? I’m sure that most of Copenhagen Wheel’s customers can put up with a little “chop”, eh?

    • Seth T Wilson says:


      • Ormond Otvos says:

        Forget it, Jake. It’s Bubba…

        • Bubba Nicholson says:

          I apologize, sometimes I stumble over my own IQ. Stop means “halt”. Quirks are expected, as with gear shifting, we must just get used to them.

          I am sorry, Mr./Ms. Ormond Otvos? Are we acquainted or perhaps you find genius intimidating?

    • Hawken says:

      You make absolutely no sense. I’m sure it sounded good in your head before you wrote it, but maybe you should try again.

  2. Freyr Gunnar says:

    Considering the cost of a good-quality bike to get started and the $700 add-on for the Copenhagen Wheel, it might be a better idea to just get an electric bike.


    • Theo Brinkman says:

      Based on the ‘Value’ options presented at that link, if you go with the Copehagen Wheel, you’re looking at another $300-$4800 to budget for your bike before those ‘value’ options are going to save you money.
      – $300, $650, or $4800 with 1/2 the range of the CW
      – $1050, $1500, $1550, $1900, $2200, or $2400 for the same range as the CW
      – $2500 with 2x the range as the CW

      The bike that leaves you with $300 is a folder, and it’s unlikely to come out ahead in a comparison between the decent $300 road bike with the CW, unless you put a *serious* premium on the folding capability.

      Since you can get a decent road bike for $300-$500, and a good road bike in the $1000 range, and a damned nice one for $2000, the Copenhagen Wheel seems like a pretty good option.

      Heck, the page you link to includes a wheel-hub kit similar to the Copenhagen Wheel for $1500. (At twice the price for twice the range, that seems pretty comparable.)

  3. Edwin says:

    I wish this was affordable but $700 is way too steep for working wage slaves like me.

    • matresstester says:

      Bike community is something for the MIT elites of the north east. Who can actually afford to live somewhere you can bike to work from?

      • Daniel Nebdal says:

        Depends entirely on the city – if you live somewhere where most of the housing is suburbs, then sure, biking is unrealistic. Other cities have a larger share of their total housing in the city itself, and then it gets more convenient.

        And it’s interesting how things change from place to place. Here, it’s more “who can afford a car” – they’re rather expensive, and since the metro+buses will get you to work fine, a car is kind of a luxury item.

      • Ormond Otvos says:

        Bicycling is how you save enough on transportation to afford where you live. For me, it’s Atchison Village. Google it. Greenways, buses, BART.

    • disqususer2 says:

      My first though was to absolutely agree with you.
      The I looked at my car expenses for 3 months or my daughters bus pass for 6 months [ plus that face that I still have to take her and pick her up from the stop ].
      They are equal.
      I know that there are those who who ride a $200 bike a few miles, hop the bus, subway or whatever.
      This expands that to folks who might have a number of really hard hills or 10 miles of riding and for those folks who want to but lack that extra little oomph .. this would be great.
      My wife works about 1 mile away, but it is almost all really steep uphill that direction and getting to work sweaty and tired would not work for her. 13 year of doing this versus a bike that would help her on those hills would so, so paid for itself.
      Your mileage may of course vary.

      • Edwin says:

        It’s rare that I can even have $700 in my bank account, so no matter how much I know it’ll save me money in the long run, you still run into the issue for people who can’t raise that kind of money in the first place.

        • disqususer2 says:

          can’t disagre – that is frequently an issue; do I buy a Prius to save 50% or do a buy a 5 year old Honda ? Do I lease a Leaf and spend 1/3 the fuel costs a month compared to any car …
          Sometimes it takes money to save money …

  4. Gekko says:

    “Just like a hybrid car, the hub’s motor can recharge while slowing down or braking. (Essentially, the motor is running backwards and converting motion into electricity.) ”

    Just to clear this up to stop any confusion, the motor is not actually running backwards. It is instead being used as a generator instead of a motor when slowing down or braking. The motor is still spinning in the same forwards direction as before, only its role is reversed.

    • Philip Jh says:

      gee wiz gekko the author did say ESSENTIALLY… Essentially, the motor is running backwards and converting motion into electricity. thats pretty much a qualification to say this is not whats actually happening but what the total outcome is. so really there is no confusion unless you like to create some.

  5. Hard Little Machine says:

    What’s it like towing a trailer full of groceries?

    • Martin LaMonicaMartin LaMonica says:

      No direct experience there, but the electric wheel would just make it easier, particularly on the hills.

  6. Hard Little Machine says:

    BTW I love the ‘regulatory’ aspects of it. Only in the EU. What next? If you weigh too much it fines you?

  7. Ormond Otvos says:

    I’d paint the center of the wheel bland silver to prevent theft by knowledgeable thieves.

  8. GordonRanger says:

    I’d paint a spiral on it, and hypnotize onlookers :-)

  9. Lorien says:

    sorry, but you have to know nothing at all about bicycles and electric bicycles to think this is a good product. For starters it’s a direct drive hub motor, that’s good for simplicity and reliability, but it’s complete crap for climbing hills and getting decent range out of the battery, and it also makes it far heavier than it should be. Then there’s the battery, it’s small, and it’s in the most stupid place anyone could ever think of to put it. The weight of it will be levering against every pedal stroke, and it’ll get hot and die faster because it’s in the same enclosure as both the motor and controller, both of which WILL heat up. Then there’s the delays: this thing is STILL in pre-production and I first looked at it in January.

    A very poorly thought out write up you should be ashamed off.

  10. Mark stephens says:

    Another option is to buy a 48 v/10ah rear rack lifepo4 Battery. With a 48volt 750 watt 26inch rear wheel bike motor kit. This setup will get you much better torque for hilly terrains. Depending on your body weight and your battery discharging capabilities of your BMS. You should get battery range between 20 to 30 miles between charges. You will find it available at http://www.goldenmotorproducts.com. You should always try to keep your battery separated from the motor and motor controller. For the simple reason to avoid the overheating of these electrical components under full load conditions