A Dynamo Bike Light That Won’t Slow You Down

Swapping your car for a bike can go a long way toward shrinking your carbon footprint (and your waistline). But for most inexperienced urban commuters, staying safe while riding is a big concern. Helmets, mirrors and bike lights help riders remain visible, as well as street legal, while traveling to and fro.

Traditional bike lights use batteries or friction to generate the energy necessary for nighttime illumination. The only problem is that batteries fade and die (and are also bulky), and friction-based lights create unnecessary drag while failing to produce a steady beam of light. Magnic Light, a product seeking funding through Kickstarter, proves that neither drawback is necessary for safe biking.

Magnic Bike Light

image via Magnic Light/Kickstarter

According to its project lead, Dirk Strothmann, the Magnic Light is the world’s first compact contactless bicycle dynamo: a new invention, that if successfully funded and brought to market, has the potential to revolutionize the bicycle illumination industry. It’s true that there are other magnetic dynamos on the market, but they require riders to attach magnets to their wheels and don’t produce constant bright light. The Magnic Light dynamo claims to eliminate this need for wheel modification and produces enough energy for a brilliant light while exceeding the efficiency of hub dynamos by a wide margin.

And just how does the Magnic Light achieve this feat? Relative movements of magnets (in the light) and nearby conductive material (in your metallic wheel rim) induce eddy currents in the conductive material. These eddy currents have their own magnetic fields which are absorbed by the Magnic Light generator kernel, producing electric energy to power the light’s CREE XM-L T6 LED bulbs. According to a review on SlowTwitch, the Magnic Light mounts onto most any side pull brake, but an adapter is also available for frames with cantilever brakes.

Beth Buczynski is a freelancer writer and editor currently living in the Rocky Mountain West. Her articles appear on Care2, Ecosalon and Inhabitat, just to name a few. So far, Beth has lived in or near three major U.S. mountain ranges, and is passionate about protecting the important ecosystems they represent. Follow Beth on Twitter as @ecosphericblog

    • Maxwell

      All power production from a wheel will slow you down – whether from friction resistance or from inductance. There’s an effective load required to power the light and that load doesn’t come for free.

      • pdxpete

        Ah, a good point, Maxwell. Question: Would a system like this be less of a drag that a system using friction? Certainly it would be quieter.

    • bkwanab

      There will definitely be drag from the magnetic field eddy currents.  Presumably there will also be the added peripheral weight at the rim from ferrous(?) material added to the rim to maximize the current generated. A setup like this would be quieter and probably even silent when in use.

      I don’t see why an arrangement like this is thought to be more efficient than a hub generator though.  Isn’t this just the same except the rim becomes the armature?  It also seems to have the added matter of excess weight at the rim that would impact acceleration and steering stability.

      I think I’ll stick with my rechargeable batteries

      • Pete Danko

        bkwanab, thanks for your comment. The maker says that with the Magnic Light nothing needs to be attached to the rim. He does concede some drag but says implies (IMHO) it will be less than with a friction device, calling it a “minimal braking effect.”

    • SWF Luthier

      I wouldn’t mind being a tester! This system would be easy enough to evaluate.

    • guest

      Looks like it replaces a brake pad????

    • Dirk Strothmann

      Many have asked, if Magnic Light is ready for sale or still in prototype mode: It is available at http://www.magniclight.com- and several tests are online, too.