Revolights Arc turns a bike's fender into a speed-detecting brake lightView gallery - 3 images
Revolights is a bicycle lighting system that first came to our attention three years ago, in which the front of the front wheel lights up to serve as a headlight, while the back of the rear wheel illuminates to act as a tail light. While it's a clever setup, at US$229 for a full kit, it's not cheap. That's why its designers have just announced a more affordable alternative called the Revolights Arc, that combines a tail light and wheel-speed-activated brake light.
The Arc can either be attached to an existing rear fender or purchased already built into one, depending on which option buyers go for.
When the rider is just cruising along, the Arc's two LED light pipes either flash on and off or shine steadily (user's choice) just like a regular tail light, although offering up a larger illuminated surface than most. Thanks to a speed sensor at the back of the device, however, it can detect when the rear wheel suddenly slows down, and at that point becomes a brake light. It then indicates that the rider is stopping by getting brighter and (if applicable) blinking more rapidly.
The Arc is powered by a lithium battery, that can be taken out and recharged via a computer's USB port. A charge of under two hours should be good for about eight hours of use.
Down the road, Revolights also hopes to incorporate a turn indicator function, which would be wirelessly activated using a handlebar-mounted controller.
As with its previous two products, Revolights has turned to Kickstarter to fund commercial production of the Arc. A pledge of US$69 will get you the light itself (that you apply to your own fender), when and if they're ready to go – the planned retail price is $89. The complete fender requires a pledge of $109.
A demo of the Arc can be seen in the pitch video below.