The Copenhagen Wheel

Bikes Computers & Mobile Energy & Sustainability Fun & Games
The Copenhagen Wheel

The Copenhagen Wheel recently demonstrated at the Copenhagen Conference on Climate Change is a clever device that can store energy every time you apply the brakes and then reapply it in the form of motor assist as you ascend a hill on your bicycle. Developed by MIT researchers, the Copenhagen Wheel also acquires speed, distance, and direction data from an array of sensors inside the device and transmits it via Bluetooth to the cyclists mobile. [via geekygadgets]

Over the past few years we have seen a kind of biking renaissance, which started in Copenhagen and has spread from Paris to Barcelona to Montreal,” says Carlo Ratti, director of the MIT SENSEable City Laboratory and the Copenhagen Wheel project. “It’s sort of like ‘Biking 2.0′ — whereby cheap electronics allow us to augment bikes and convert them into a more flexible, on-demand system.

24 thoughts on “The Copenhagen Wheel

  1. Word Bitch says:


  2. J.Noe says:

    It’s spelled CopenhagEn

  3. sire says:


    How much weight does this thing add to the bike?

    I remember the same idea with someone putting a electric motor on a bicycle, so that when you go down hill, it charges energy for you to go uphill…..

    Except the added weight makes it much harder to travel uphill in the first place.

    Same deal with the braking. After you’ve braked, you’ll expend more energy combating the inertia the extra weight causes, to make any “energy boost” negligible.

    Either have an electric motorbike with enough batteries so you never have to pedal, or you make the thing as light as possible and use pedal power only.

    Those safety features probably weigh alot aswell.

    Unless they’ve figured out how to make copper way less heavy, or have designed a generator with 100%+ efficiency, this thing is probably useless….

    Which won’t stop a bunch of people buying them.

    1. RocketGuy says:

      Is likely lipo batteries. I note at least 6 cells of lipo in there, so this might not be so useless after all. Also electric motor/generators have advanced quite a bit, particularly due to the RC market. The electronics are negligible in additional weight, so the power to weight ratio may be a lot higher than previous versions. While the copper might not be any lighter, how hard it’s worked has improved with better rare earth magnets and better designs.

      So basically you have a hill-leveler, which for some might be quite helpful.

      Proof is in the pudding as usual, so it will remain to see how it stands up in actual use, but dismissing it out of hand based on older versions that didn’t have today’s battery tech or brushless motors seems a little grumpy.

      1. RocketGuy says:

        After looking more carefully at the exploded view, I’m guessing 12 cells of lipo, for up to 44V, depending on configuration. That’s a significant power sump.

      2. sire says:

        There’s no point putting any kind of battery on a bike that you intend to peddle the majority of the time.

        The weight of the motor, the batteries, and the associated electronics will far outweigh the tiny amount of energy you could get back from breaking. Peddle power is acutely tied to weight and inertia.

        In fact I’d wager the regenerative system alone, let alone the electronics and lock weighs nearly as much as some entire bikes (there are some carbon bikes that weigh as little as 4kg).

        Regenerative braking is a neat idea for something like cars where you actually have to brake alot and can actually get sizeable energy back.

        With peddle bikes you would have to brake so many times to get any sort of charge, its near pointless, especially since you have to peddle harder to carry around the extra weight, which you’ll be doing the majority of the time.

        If you value your own energy at 0, then yeah this thing is great.

        The only way this could possible of benefit is if you needed to brake hundreds of times a day, and at the end of each week you needed to peddle up a mild slope. Then it might actually serve some use.

        The recording electronics are kind of cool, but nothing we haven’t seen already, and the regeneration system is just bad physics.

        Unless you can build a regenerative braking system for a peddle bike that essentially has 0 weight, its going to cost you more energy to peddle around the extra weight all day, than you’re going to get back on the maybe 1% of energy recouped in braking.

        Put this on the “good idea till you think about it for a minute” pile, along with wind turbines on cars, the Segway and the Sinclair C5.

        1. Andy L says:

          You seem to make a good point, but I’d want to see the math before I believed you.

          In the city, bikers stop and start a *lot*. How much energy can be gained from each of those brakings, I don’t know.

          If the math worked out to be borderline, the psychological impact of having a “boost” at exactly the hardest part of your ride might be worth it.

  4. Anonymous says:

    Spelling is hard.

    1. Zero says:

      For any bicycle parts thief out there. Since everything is all self contained and you need only slightly loosen two bolts these things will be a snap to grab!

      Oh, and who cares that there are already electric assist bicycles out there, this one has BlueTooth so you can constantly collect worthless data on your iPhone and constantly tweet how far you’ve traveled; helpfully alerting anyone you know you’re a total looser! Wheee!

      1. matt says:

        actually it would be 3 bolts, needing 2 wrenches and a screwdriver.

        1. matt says:

          and that looks like a cinelli frame so its probably worth more than the wheel

    2. Anonymous says:

      Anonymous on December 18, 2009 at 6:28 AM said,

      “Spelling is hard”.
      Sometimes, it can be. However, if one is observant, one would realize that peddling bicycles rarely happens. They are sold in stores or privately, for the most part.

      Your shoes push down on pedals, not peddles. When you make the bike move while seated (or standing on the pedals), you don’t peddle the bike, you pedal it.

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