Consumers currently have their choice of several brake lights for bicycles, which use an accelerometer to detect when the cyclist is stopping. However, what if you want something that's a little smaller, simpler and cheaper? That would be Sigma's tiny new mechanically-activated Brakelight.
The water-resistant light is attached by the rider using an Allen key, to the rear brake cable between the two brake calipers (the company claims that it's compatible with any cable-activated mechanical rear brake). When those calipers are subsequently squeezed together while braking – even slightly – they cause a mechanism in the brake to likewise close up, completing a circuit and illuminating the single red LED.
The Brakelight weighs 7 grams, and is powered by a replaceable 1025 button cell battery that should be good for about 100,000 braking processes. It's available in five colors, priced at US$9.99. You can see it in action, in the video below.
And in case you're thinking "Wow, it's amazing that no one thought of that before" ... they did. At the 2013 Interbike show, we spotted a similar product made by S-Sun Enterprise.