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Bike Lights

man riding a road bike in the rain using a helmet light and handlebar light

Bike Lights: The Basics

Whether you are an early-morning commuter, a nighttime mountain biker, an all-weather racer or just a casual rider, proper lighting on your bicycle is very important for safety. Unfortunately, many cyclists are hurt every year because they were riding without proper lights.

Many of these accidents could be prevented by using inexpensive, widely available bike lights, and that’s why we recommend that every rider keep a set of bike lights with them on every ride -- you never know when you are going to get caught out after dark.

This article will go over the most common styles of lights available today, the pluses and minuses of each variety, and the factors that cyclists should consider when making their choices.

Bike Taillights/Rear Safety Lights


The first and most basic style of light on the market is the rear safety light. Like the brake lights on a car, these rear lights are always red in color, and are most often used in a bright flashing mode to attract the attention of drivers approaching your bike from behind.

Different bike taillights have different mounting options. Some are designed to clip onto the back of a rear rack, while others clamp onto your seat tube. Some riders choose to mount their rear lights on their backpack or even the rear side of their helmet, or to use several rear lights on different locations. Many riders take their lights with them when they lock their bike up in public, while others don’t worry about the (generally low) possibility of losing these cheap lights.

If there is only one light that you buy, make it a rear safety light. These can cost as little as $5, and generally use standard AA or AAA batteries that can last for 200 hours or more -- months or even years for the typical rider. Riders desiring even more battery freedom can use standard rechargeable batteries for a more waste-free charge.

Rear lights are generally waterproof and are designed to be used in the rain without any adverse effects.

Front Safety Lights


If you are riding in any sort of dark or low-visibility situations, a front safety light is also a necessity. Again mirroring the lighting pattern of a car, front safety lights are white in color. Like rear safety lights, these front lights generally feature a blinking mode and a solid-beam option, and they generally use LED bulbs for light output, durability, and low cost. Some use halogen bulbs, which are lower in cost but not as long-lasting or bright.

Front safety lights are designed to make you more visible to vehicles, pedestrians and other cyclists around you, not to provide illumination of roads and trail hazards for you. While these will be a great deal better than nothing if you get stuck out after dark on a remote trail or a road without streetlights, they aren’t something to rely on as a primary means of illumination.

These lights are generally low in price, usually ranging from $20-$40 dollars or so, and generally attach to the front handlebar. They are powered by the same standard AA or AAA batteries as used in the rear. Battery life averages 20-40 hours.

Bike Headlights


If you are looking for real illumination for the darkest trails, pre-dawn rides, or evening commutes, you will want to purchase a powerful light for the front of your bike. These headlights generally use larger rechargeable battery packs and the brightest bulbs for maximum light output.

Front visibility bike headlights generally pump out huge amounts of light, with brightness being measured in lumens. The higher the lumen output of a given light, the more powerful it is. Generally, 300 lumens or more is enough for general illumination while riding late at night. The strongest front visibility lights are potent indeed, even able to outshine a car’s headlight at more than 3000 lumens. These most powerful lights are generally used by night racers who need maximum performance in the darkest conditions.

Powerful front lights use rechargeable battery packs almost exclusively. Older NiMH batteries have generally given way to Lithium Ion battery packs, which hold more power and allow longer run times. Battery life ranges from as little as one hour at maximum power to as many as 40 on lower settings.

Generally, users have the option of mounting their headlights on either their handlebars or helmet. The former option is best for general use and keeps weight off your neck. The helmet-mount option is useful for twisting trails. Some riders choose to double their safety by using two front lights, one helmet mounted and the other on the handlebar.

Front visibility lights are also generally waterproof and often use high-output LED or HID (High-intensity discharge) bulbs, which are brighter than LED bulbs but are more expensive and more fragile. Powerful front lights range in cost from around $70 for basic models to more than $500 for the brightest, longest lasting models.

Emergency Lights


One final category of lights worth mentioning is the emergency light category. Generally, these lights cost just a few dollars, run only a few hours, and are small enough to fit a few in every pocket of your jersey or in your seat bag. Many emergency lights feature small elastic bands to allow them to be attached the handlebars or other areas on your frame. If you ride much and sometimes don’t bother to bring a light set, it can be a great idea to have a few of these on hand for unforeseen emergencies.