By their sheer power alone, lights that emit 400-700 lumens (or more) serve as both “see with” lights and a “be seen” lights. Unfortunately, powerful lights are expensive, and not every bike commuter is in the position to spend $400+ on a bike light. An alternative is to combine a pair of relatively inexpensive lights: one with a tightly focused beam pattern to see with, and one with a wide angle beam pattern to be seen by.
A relatively low output light with the right beam pattern can put plenty of light on the road for typical commute speeds. The trick is to take that small amount of light and concentrate it where it’s needed — on the road right in front of the bike. A good “see with” light should emit at least 100-200 lumens and have a narrow, focused beam. Here are a few possibilities:
- Fenix L2D Q5 (180 lumens – $69.99)
- Light & Motion Stella Double-Eh (120 lumens – $89.99)
- NiteRider MiNewt Mini (110 lumens – $100.00)
“Be seen” lights should have relatively wide angle beams and large diameter reflectors to create a large visual footprint and good side lighting. Here are a couple of possibilities:
High output lights often use proprietary Li-ion batteries that are very expensive to replace. After being taken to the cleaners more than once when replacing a proprietary battery, I’ve opted to use lights that accept off-the-shelf rechargeables in AA and AAA size. With today’s highly efficient LED emitters, it’s possible to get 100-200 lumens and reasonable run times with AA batteries.
My current set-up includes a Fenix L2D and a Busch & Müller Ixon. The sharply focused L2D is pointed down toward the road and provides a well lit patch in front of the bike. The Ixon is pointed straight forward and level; its large reflector and diffuse beam signals my presence to motorists both in front and to the side.
This set-up is just one among many possibilities. The important thing is to use a combination of at least one tightly focused beam, and one wide angle beam. And if your budget allows, forget all this two light stuff and look into a good hub dynamo system or one of the many high output LED systems on the market; they’re expensive, but worth every penny.