Bicycletest.com
November 2003

ARC Li-ion

Daylight Saving Time is over, which used to mean the end of after-work rides. But now, thanks to super-bright HID (high-intensity discharge) lighting systems like Light & Motion’s ARC Li-ion, it’s possible to not only ride after dark, but see our way at full-blown racing/training pace.

First-generation HID lights were as hefty as they were bright, but that’s not the case with the ARC Li-ion, which weighs just 515 grams for lamp and battery (almost 400 grams lighter than similar lamps). The big weight savings comes from the lithium-ion battery, which is the same type you’ll find in high-end cell phones and laptop computers. It’s small and unobtrusive, whether it’s strapped to the frame or tucked into a jersey pocket.

HID bulbs create a fierce output, and the ARC’s design makes the most of it with a peened aluminum reflector that gives it the best beam pattern we’ve seen, with a bright center and a broad flood that lets you navigate full-speed through the light and dark patches of city streets.

Light & Motion claims a burn time of 3 hours on the 13.5-watt high setting, but we recorded a burn time of 3 hours 50 minutes on high, a full 20 minutes longer than the advertised burn time if the light’s run at the 11-watt low setting. That’s impressive, and should be plenty for nocturnal training rides or the longest commute home.

While the ARC offers plenty of run time, it should be noted that HID lamps take a significant amount of power to fire up, and repeatedly turning the lamp on and off will significantly reduce run time. Charging was a snap. The battery’s on-board brain allows for a rapid charge up to 80% of a full charge, before switching to a trickle for the last 20% to avoid damage. Because it can utilize anything from 90-260 volts, chances are you can find a place to charge it as long as there’s an outlet.

The only thing we would really like to see improved upon is the release of the lamp from the handlebar mount, which makes it awkward to swap the lamp between the included handlebar clamp and helmet mounts. It’s not impossible to do, but it could be easier. It would be great if it was cheaper, but then new technology is never cheap.

While it is definitely overkill for the occasional nocturnal outing, those of us who are nighttime regulars will love this kind of lighting firepower, on pavement or off-road (a helmet mount is also supplied, but shouldn’t be deployed on the road—it’s questionably legal, and blinding oncoming drivers doesn’t enhance anyone’s safety). If you can stomach the price, it will be all the light you’ll ever need.