bike light basics

Riding after dark is safe and enjoyable, assuming you have the appropriate equipment. Lights and reflectors are the best way to stay visible when riding at night. Reflectors are nice because they are often built in to bikes and clothing, don’t require a power source, and are lightweight. However, reflectors also require an outside light source to be effective. If headlights are not shining on your reflectors (when approaching cars from the rear or side or when approaching pedestrians), they won’t help. Lights maintain visibility in these situations and can also allow the operator to see their surroundings better.

Two lights are adequate for night rides. Ann Arbor city code requires that any bicycle operated from ½ hour before sunset until ½ hour after sunrise have a functioning headlight and red rear reflector or light. Thanks to LED technology, both can be purchased cheaply and are easy to mount (and remove to prevent theft), lightweight, and require little power. LED lights are recommended because they are much cheaper and lighter than halogen lights. They are also often much brighter although the light is not focused, so they are better for being seen than for seeing.

LEDs also use much less energy, so batteries will last a long time. Generators remove the need for batteries altogether, though they provide less light than powerful rechargeable systems but more than the smaller halogens. Rim- or tire- driven generators are least expensive and easiest to install; hub generators are most efficient and reliable, but cost $150-$250 (including the cost of building a new wheel around the hub).

A front light is most important and legally required. It is usually mounted to the handlebars or to the rider’s head or helmet. Mounting to the rider instead of the bike makes it easy to direct the light in the direction the rider is looking. Some front lights also have a “halo” ring of light, which makes the cyclist more visible from the side. A decent front light will set you back $20-30.

Rear lights are required to be red. They are generally small, round and really cheap ($5-15). They can be mounted on the seat post, seat stays, or on your body with a clip. If you mount it on your body, make sure it is visible when you are in riding position.

Always make sure your lights are functioning and clean (dirt on the lens can drastically cut down on the effectiveness of the light) before setting out on a ride that will end in the dark. To avoid running out of power and fading lights on a ride, change batteries regularly. If you change them every time you do other basic maintenance (lube chain, refill tires, tighten cables) you will avoid batteries dying during the trip. Rechargeable are always a better option.

much of this info was taken with permission from WBWC carfree wiki.