Revolights Arc turns a bike's fender into a speed-detecting brake light
The Revolights Arc knows how fast you're going, and shines accordingly
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.
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
With the longevity of LEDs, it really is about time that all bikes were required to have built in (i.e. not easily stolen) lighting to a level and standard that motorised vehicle drivers can see at a glance and know that they are approaching a cyclist and drive accordingly. (They should all fire in bursts of three followed by a brief a pause, but that is only a preference on my part.)
Given the minimal current requirements of LEDs, surely the power supply could be generated as the wheels rotate, it is hardly new technology.
Wouldn't just be easier to use a switch attached to the brakes.
Of course the power supply could be generated as the wheels rotate but it would involve magnets which create drag and require extra physical effort by the rider. I have used the magneto type bicycle lights some 50 years ago and it was really tiring !
I agree with Mel Tisdale on all points.
I particularly like his suggestion that cycles should have a signature light pattern ''bursts of three, plus pause'' or whatever, but something uniform and distinctive. Excellent idea !
The generator you used had really bad bearings that ate about 20 times the energy that was converted to electricity.
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