CIO bike lights use smaller magnets for more power

For over a decade, Danish

manufacturer Reelight has been making bicycle lights that are powered by magnets mounted on the bike's spokes. That means no batteries are necessary, so the lights can be used all the time, day and night. Additionally, the magnets create very little rolling resistance, which certainly isn't the case with those tire-rubbing dynamos. Now, the company has set about making its lights more compact and more powerful, with the CIO.

With Reelight's old setup (which is reportedly installed on approximately a third of all bikes in Denmark), two relatively large magnets are mounted on each wheel. By contrast, CIO uses just one "coin-sized" magnet per wheel, plus the lights themselves are smaller. That said, their power output is six times higher than that of the existing model.

Because they're intended to be in use all the time, the waterproof CIO lights have no switches or other controls – you just start riding, and the revolving magnets engage generators in the lights, causing them to start flashing. Thanks to built-in capacitors, they keep flashing for up to two minutes when the bike is stopped.