The team that brought you both the Revolution and Reactor dynamo hub charging systems are just about to release a new dynamo light. Called the Sinewave Cycles Beacon, it’s a bit different to the current crop of dynamo lights.

The defining feature of the Beacon is the way it is powered. The Beacon can be illuminated directly from the dynamo hub, from an external battery pack, or from both simultaneously. With an external battery engaged, you can achieve the full whack of light from standstill. As your speed increases the power source will switch from the battery across to your dynamo hub. And when you slow down, the light will source power from the battery again so that the beam doesn’t dim or flicker.

Not only will the Sinewave Cycles Beacon achieve a consistent beam of light, but it will charge your devices as well. Using the same circuitry as their USB chargers, the light will produce a constant USB charge from the relatively low speed of 12 km/h (7 mph).

Weight: 115 grams with 91cm (36″) dynamo cable
Price: US $325
Origin: Made in the USA

The Sinewave Cycles Beacon Light

The Sinewave Cycles Beacon has a maximum output of 750 lumens. That is brighter than Supernova’s E3 Triple (640lm), but not quite as bright as the Exposure Revo (800lm) or K-Lite Bikepacker Pro (1200lm). I’ve found that anything in the 300lm+ range tends to be fine for road use, although the higher outputs are nice for tight, off-road singletrack riding.

As with all dynamo lights, the Beacon gets brighter the faster you go:
200 lumens at 8km/h (5 MPH)
500 lumens at 13km/h (8 MPH)
650 lumens at 16km/h (10 MPH)
750 lumens at 21km/h (13 MPH)

The lens is symmetrical in design, making the light the same brightness across the whole lens and allowing you to mount it in any orientation. The type of lens design is great for off-road use but tends to be rather distracting on the road for anyone approaching from the opposite direction. For this reason, symmetrical lenses are actually illegal to use on the road in some countries, instead favouring a lens design which funnels the light output to the lower portion of the lens.

Inside the lamp is a supercapacitor which holds a small amount of power so that the light can stay on for about five minutes after use. A taillight output wire is pre-installed so you can connect up almost any rear dynamo light.

Charging Via USB

The Beacon has a USB port built right into the back of the light. You can plug your phone or GPS directly into here, or you can use a USB extension cable to charge your device elsewhere. When the light is switched ‘off’, you’ll get the maximum amount of power from the dynamo hub for charging. Conversely, when the light is in ‘high’ mode the charger will still draw a current however at a greatly reduced rate.

A middle function called ‘Charger Priority Mode’ allows for both the light and charger to work simultaneously. The light draws enough power to run on a low setting and the remainder is sent to the charger. At slow speeds, this results in the light taking almost all of the power, but the faster you go, the more you can generate for charging. If your device is done charging, all power can go back to the light (the same functionality as the ‘high’ mode).

Using the Light Via Battery Power

When the light is drawing power from the dynamo hub, the light output is always maximised. Sinewave Cycles say that “power is optimised at low-to-medium speeds, providing much more light in this range than any other headlight.”

But if you’re powering the light from a battery, you can toggle between the low (100lm), medium (250lm) or high (600lm) settings to suit your conditions or choose how long you want to extend your battery life.

Weatherproofing

A concern for many is the idea of having an exposed USB plug which water, mud and grit can potentially damage. While it seems crazy not to provide a cover, this is not dissimilar to other products on the market such as The Plug III or Sinewave’s own Reactor. As bikes are very rarely submerged in water, and the USB port is somewhat protected behind the light, Sinewave Cycles deem a cover unnecessary.

Multiple seals are used to stop water ingress, and the exposed plugs also use non-corroding connectors. Internally everything is made water resistant and the electronics are potted in epoxy. While not impervious to water forever, the weatherproofing should be adequate for the service life of the light.

Other Similar Products

AXA Luxx70 Plus – This great value light/charger is only US $100 and although not as bright, still does an adequate job.
Busch und Muller Luxos U – The Luxos U (US $219) has set the standard for headlight charging units for the last five years.