Modern technology has breathed new life into a relic of bike riding from an earlier age — the bottle dynamo.
Before LEDs and rechargeable batteries the bottle dynamo was how bike riders could get out at night an in poor weather.
You clipped the small, metal, power generator against your tyre and set it humming as it produced a sufficient trickle of electricity along a skinny wire to provide a feeble beam from a streamlined, chrome bike lamp (if you were riding fast enough).
The beam brightened and faded depending on speed.
Although one still sees the occasional 40 year old steely on the street, so equipped, the dynamo basically went the same way as the dodo: extinction.
But now, thanks to science, the species is reborn.
US start-up, PedalCell, has rethought the dynamo from the bottle up and reckons its new product has enough advantages to find friends in the market place.
Their device, called the CadenceX, features a rubber-edged wheel that spins as it presses lightly against the bike's front wheel rim.
That spinning motion generates electricity, which is sent via wiring to a capacitor-equipped handlebar-mounted Smart Power Hub that in turn regulates the current, feeding it out stably and consistently regardless of cycling speed.
Delivering a maximum of 20 watts, the device is claimed to power just about any other bicycle-mounted electronic device – these could include lights, electronic shifting systems, phone chargers, cycling computers or action cameras.
Additionally, because the capacitor stores a limited amount of power, those devices are able to keep running when the bike is stopped for short periods.
Although the dynamo wheel does create some drag as it spins, built-in sensors detect the acceleration, speed and inclination of the bike, automatically adjusting resistance at slow speeds or climbing hills, and increasing power output during braking.
There are existing hub dynamos on the market, popular with many European commuters and touring cyclists.
But according to PedalCell they are heavier, more expensive and less powerful.
Their modern rim generator is able to combine high spin speed with special generator winding to producer seven times the power at one quarter the weight of a typical hub system while travelling at a realistic 20 kph.
Currently PedalCell is aiming to sell to the bike industry rather and directly to consumers. The dynamos should be on some new bike models late this year and early 2020.