LIGHT & MOTION SOLO LOGIC MvA small, powerful light for all seasons

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As a regular bike commuter with a 50-mile round trip to work, I knew I would need a reliable light to get me through the early darkness of fall and winter.

The Solo Logic Mv from Light & Motion definitely fits the bill. It's amazing how much light this tiny unit throws onto the road.

A serious light

The Solo Logic is geared toward commuters -- Light & Motion calls it their "most reliable and practical light." By contrast, Light & Motion's high-octane ARC Li-ion model (read the Active review) is powerful enough for the pitch-black conditions encountered by 24-hour mountain bike racers or adventure racers.

For all its practicality, the Solo Logic is still a serious light for serious cyclists. Weight-conscious road riders will appreciate its feather-lightness (light unit, 54g; battery, 320g) and streamlined set-up, while every rider will appreciate its durability and wide, powerful beam.

The lamp

The Solo Logic lamp head comes with two mounts: the "Lefty" handlebar mount and the "Cabeza" helmet mount. I chose the bar mount -- it screws easily and securely onto your handlebar -- no tools needed.

The lamp snaps in, and pivots up and down and side to side, so it's easy to point the light beam exactly where you want it, even on the fly. This multidirectional pivoting also helps the lamp head move with impact in the event of a crash -- it's not rigidly locked into one position. If necessary, a built-in "breakaway disk" will snap, which saves the lamp body and mount.

The lamp body is sealed against water, and the adjustable bezel lets you narrow or widen the beam depending on conditions.

The Solo Logic casts a 15- or 20-foot-wide penumbra of light around the central beam, giving you a really wide field of illuminated vision. There are bright mini-light ports on the sides of the lamp head, which 1) help to make you more visible from the side, and 2) light up your cockpit a little bit so you can see your computer.

When you fire up the light, the Solo Logic's "Soft Start" technology allows the lamp to reach full power gradually (within a few minutes), avoiding the chances of blowing the lamp at start-up.

Light & Motion lamps are made of optical quality glass, and give off a very "white" beam due to their extremely high color temperatures (up to 3,400 K, for you physics majors).

There are three different "light output" (power) settings on the Solo Logic, each of which increases the burn time slightly -- from 2 hours (at 13 watts) to 4 hours (at the lowest 6-watt setting). The light dims slightly with each click of the single power button.

Another Solo Logic feature to protect battery life is "Reserve Mode": With about 15 minutes of power left, the LED light on the lamp will flash and the light will automatically drop into the low-power (6 watt) mode. At the end of 15 minutes, the system automatically shuts off to prevent battery damage, and can only be re-started if a fresh battery is attached or the depleted one is recharged.

The battery

The Solo Logic comes with a 7.2v NiMH (nickel metal hydryde) battery pack, which connects to the light head with a built-in cord. Also available is the optional, more powerful Lithium Ion ("Li-ion") 11-volt battery, and a 10.8v NiMH Slimline battery. The "Mv" designation in the Solo Logic's name means it can be used with any of the batteries Light & Motion makes.

Light & Motion has newly redesigned their battery packs, dropping the previous design (a round model that fit into your bottle cage) in favor of a fist-sized squarish model equipped with a Velcro strap that wraps around your top tube, seat tube, seatpost, or wherever you can fit it. The contact points on the battery pack are rubber-coated to make it more sticky.

The battery re-design is mainly due to the growing popularity of full-suspension mountain bikes, and the limited bottle-cage locations on these frames -- you wouldn't want your only bottle cage taken up by a battery.

Battery installation

Because I carry a frame pump on my top tube, I attached the battery pack to my seat tube. When you strap on the battery -- here's where it pays to read the instructions! -- if you just throw the battery pack on your bike and go, you may discover (as I did at first) that you haven't tightened it enough, and it doesn't stay in place very well. As I rode, road vibration would cause the pack to shift to one side, so that my leg would hit it with each pedal stroke.

It was only after a few rides that I took a closer look at the owner's manual, which spells out a trick or two for securing the pack tightly. Problem solved.

Other rider/reviewers I have read (including mountain bikers) for Light & Motion products have said they had no problems securing the new battery-pack design, so it's just a matter of practice and paying attention to the instructions -- the new design is worth it for the weight savings, and it frees up a bottle cage.

The Solo Logic comes with a 14-hour trickle charger that plugs into any standard wall socket. The light will work on a less-than-14-hour charge, but burn time may be shorter on a less-than-full charge. Cyclists who ride every night may want to get Light & Motion's optional Turbo Charger, which fully charges any of their battery packs in just 3 1/2 hours.

The "Logic" in the Solo Logic's name refers to its automatic-shutoff feature when the battery is discharged, to preserve battery life.

The bottom line

The Solo Logic is solid, durable and cleanly designed, and you hardly notice it's there. It's tremendously bright for its tiny size. It's a bike light you can count on for any kind of night riding.

Suggested retail price: $209.95

Light & Motion, based in Monterey, Calif., was founded in 1989. The company initially specialized in underwater lighting and video systems, and branched into cycling lighting systems in 1999. They developed the first high-intensity discharge (HID) bike light and Lithium Ion battery systems. For more information, check out their Web site.

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