Bicycle with USB ports to charge devices off a built-in dynamo

German bike-maker Silverback has a new bike that incorporates a dynamo into the wheels that powers a recharging USB port on the handlebars, so you can charge your phone or tablet while you ride.

The Starke 1 and 2 models come with a USB port that uses power generated from a dynamo front hub to provide a charging point for gadgets like GPS units and smartphones



  1. I’ve been doing that for years. Hub dynamos are pretty common in (some parts of) Europe and have been for quite a while. I built my own circuitry and wired the plugs on my own though; fried quite a few batteries in the process ;-).

    Nowadays there are a number of (battery-buffered) commercial products that you just plug into your hub dynamo. Much easier.

  2. Peter White Cycles is an excellent resource/supplier for anyone interested in bike dynamo lighting or power. Full disclosure – he built a wheelset this summer for my night and snow bike that I am completely satisfied with.

  3. More specifically, it uses products from Supernova.  They’re made in Germany and super bomber.

    Waterproof and super well engineered.

    1. Most hub dynamos are designed for 3W/6V (many are limited to this) or 6W/12V (not quite as common) output. A good(!) dynamo is about 60% efficient at normal cycling speeds, which means roughly 5-10W power consumption. Depends on the device you attach to it though; a hub dynamo will only produce as much power as your device draws.

      A typical rider will  produce upwards of 150W of power; pretty much insignificant in other words ;-).

    2. There are some graphs here (via Jan Heine and the excellent Bicycle Quarterly). I don’t notice much additional resistance w/ no load on the Shimano DH-3N80 I have, but it ain’t no race bike. Unsurprisingly, I’m no Eddy M. either – I don’t mind chugging up a hill like the robust, as opposed to gracile, older guy that I am ;-). 

    3. Totally depends!  The two hub generators I have I barely notice at all and just leave them on all the time.  I have a newer bottle generator that is noticeable but not unbearable and an older bottle generator from the 70’s that sure helps to provide a good workout.

  4. A very practical answer to the resistance issue is to disengage the dynamo when pedaling uphill and engage when coasting downhill.  This principle is used in hybrid autos when braking.

    1. Old Sturmey Archer dyno-hubs are in demand for these kind of projects. Particularly the dyno-3 and dyno-4 models, which integrate the dynamo and internal gears in a single unit, as this enables the fettler to adjust the gearing for windspeed. 

  5. I’d rather have a dragless¹ magnetic induction generator.

    ¹ drag from magnetic fields negligible in this application.

    1. Pretty sure that this is how a hub dynamo operates. Drag from a good one is very low – the equivalent of a 3 foot incline over a mile or so.

      This idea is not a new one – there are plenty of retrofit chargers for dynamo systems. It’s nice to see it well-integrated in the build – not wires dangling everywhere.

  6. I was thinking only today I need to work out how to power fairy lights from my dynohub in the runup to Christmas…

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