This Bike Light Is Always On Because It’s Powered By Your Pedaling

The spinning wheel creates a magnetic field that charges the light–a sleek design that never requires batteries or extra weight.

Pedal-powered bike lights aren’t new. But the clunky generators once common on 1950s cruisers made it harder to ride, since you had to give an extra push to charge the light. The newest generation of bike lights don’t actually touch the wheel–the power comes from the magnetic field created as the wheels spins around. As long as you’re riding, the light will never go dead.


It also has a lot of advantages over standard modern bike lights. “You don’t have to ever buy batteries, you don’t have to worry if your batteries are flat, and also this is much better for the environment,” says Christina Volmer, product manager for Reelight, the Danish company that makes a series of the lights.

In a study of 4,000 riders, the company found that the lights were able to reduce the chance of accidents by as much as 35%. The designers argue that it’s safer than other bike lights because it’s always on–it never stops working, and unlike a rechargeable light, you don’t have to take it on and off the bike (and potentially forget it). Because it runs automatically with no extra effort, it also works as a running light during the day.

“When they are always on the bike, you actually have lights on during the daytime and fog where you normally maybe would have left the bike lights at home,” Volmer says. “This makes you visible at all times. If you don’t get home by the time it gets dark like you planned, the lights are still just on, so you never have to worry about being visible in traffic.”

The lights attach to both the front and back of the bike, with a wider beam in the back so it also shows up from the side. When someone stops pedaling at a traffic light, the light is designed to keep shining temporarily.

The newest version–at 118 lumens, brighter than earlier designs–is crowdfunding on Kickstarter.

About the author

Adele Peters is a staff writer at Fast Company who focuses on solutions to some of the world's largest problems, from climate change to homelessness. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.