Basic Guide To Bike Lights
You can make an easy argument that in addition to a helmet, bike lights are the most important accessory a cyclist can buy. They make commuting in low or no-light situations safer, because it’s easier for drivers to see you. Lights can also extend your riding window, allowing you to ride on- or off-road in the early morning, evening, or even in the middle of the night.
That’s great news if you live in a place where it’s too hot to ride during the middle of the day (say, Phoenix in August), or if your neighborhood trails are overrun during day and you’d rather avoid the crowds (think Southern California). Plus riding at night can be an exhilarating experience, providing a whole new perspective on a familiar trail or road.
So which lights are right for you and your needs? We’ll help you figure it out. First, we’ll go into some of the more technical details you need to consider, and then we’ll give you some questions to consider when buying a light.
TYPES OF LIGHTS
Lights can generally be broken down into three basic types, based on their light output.
Road Bike Safety Lights: These have low light output, meaning you’ll be seen by motorists, but they won’t light your path very well. These work great for road cyclists in moderately lit areas, or any time you need to increase visibility. Safety lights are small, compact, lightweight and run on household batteries. They easily attach to handlebars, a helmet or seat post, and when combined with a taillight, they typically meet the minimum legal lighting requirements in most states.
Commuter Lights: These provide medium light output, allowing you to see the road and others to see you. They’re great for road cyclists who have to ride on poorly lit roads, or slow off-road trail riding. Weight varies depending on model. They must be combined with a taillight for safe road riding.
Mountain Bike Lighting Systems: This high light output option is best for off-road riders or riding on county roads with no additional light source like street lamps. Lighting systems come with rechargeable, high capacity batteries, allowing for long run-times and good battery life. Weight is typically greater than safety or commuter models, though some race specific lighting systems are surprisingly lightweight. They must be combined with a taillight for safe road riding.
Once you’ve decided on the type of light you need, you’ll next need to determine the necessary light output. Light output is typically measured in one of two ways: watts or lumens. Watts is probably the least accurate measurement because it’s a measure of power used by the light, not light produced. An inefficient light uses more power but is less bright than an efficient one.
Lumens are a measurement of the total amount of visible light emitted from a source. While flawed, this final measure still offers a somewhat accurate means of comparing the brightness of different lights, especially those from the same manufacturer. Here’s a basic breakdown of lumen output levels.
25-50 lumens: Safety lights to let drivers see you
100-200 lumens: Bright enough to actually be able to see with
200-300 lumens: Great for road riding
400+ lumens: Appropriate for road and mountain bike riding
600+ lumens: So bright motorists will think a UFO is about to abduct them
Virtually all of today’s bike lights use some form of light emitting diodes (LED). Compared to the halogen and HID bulbs used of the past, LEDs have longer run times, are brighter and have a longer lifespan. Halogens might have to be replaced yearly. LEDs last the life of the light. LED’s are also less fragile, making them perfect for withstanding the rigors of mountain biking — and even the occasional crash.
More expensive systems will use more sophisticated, brighter LEDs. Both non-rechargeable and rechargeable lights are made brighter by using multiple LEDs, but a 5 LED non-rechargeable light like the $30 Axiom Flare will not be as bright as a single more technologically advanced LED on a rechargeable system like the $100 Light & Motion Vis 360 Headlight.
Different light patterns are cast depending on the bulb and its reflector. The most common patterns are floods and spots. Floods projects light in a broad swath, usually around 30 degrees. For the same lumens its light is less bright and more diffuse than a spotlight. But the wider coverage enables you to see potholes that are not in your direct line of sight, and even the loops and turns of a rocky mountain bike trail. However, distant objects are harder to see when using a floodlight. Spots, on the other hand, have a tighter, 10-degree lighted area and more concentrated pattern, making them suited for a rider wanting to see farther up. Spotlights are great for faster road rides.
Modern rechargeable lighting systems commonly use two different types of batteries. Each has pros and cons. Nickel Metal Hydride (NiMH) batteries are lighter for comparable run times than Nickel Cadmium (NiCad) and sealed lead acid (SLA) batteries. They are reasonably priced and last a long time. Lithium Ion (Li-Ion) use the same batteries found in modern electronic gadgets like iPods and mobile phones. These batteries have a much higher energy density than traditional bike light batteries like NiMH. This means that Li-Ion batteries store more electrons by volume than other batteries which in turn means you can have longer run times with a lighter battery.
RECHARGEABLE VS. NON-RECHARGEABLE
Most safety lights run on standard batteries and are not rechargeable unless you buy rechargeable batteries. Commuter lights vary from model to model. Lighting systems are always rechargeable.
For the rider on a tight budget, non-rechargeable head lights and tail lights fit the bill. They’re inexpensive and use readily available batteries. They do a fine job in low light, dawn and dusk riding, or on lit city streets where being seen is more important than seeing. Just remember you can’t see well with these lights, and the batteries have to be replaced regularly, usually every 20 to 30 hours depending on the model.
Rechargeable headlights, on the other hand, are brighter lights that have a battery that can be recharged hundreds of times. Depending on the cost and technology of these lights, they will be four to 60 times more powerful than their non-rechargeable cousins.
For lights with rechargeable batteries, you’ll need a battery charger that’s compatible you’re your light. Most lights run on a specific voltage, so only use the charger that came with your light, or you could risk damaging or destroying the battery. Battery chargers use an external power source like an electrical outlet, USB port on your computer, or adapter of the cigarette lighter plug in your car. The simplest systems require about eight hours to reach full charge. More expensive charging systems shorten this time to 2-3 hours.
PROGRAMMABLE VS. STANDARD
Standard lights usually have 3-4 light levels (low to high and blinking) but some are programmable. The NiteRider Pro 3000, for example, has a micro processor that can be infinitely manipulated with their D.I.Y. Software. Using your computer you can fully customize light output, flash modes and runtime to best fit your riding style and needs.
Taillights are inexpensive, usually ranging from $12-$30. They typically use less sophisticated LEDs and are made brighter by using more of them. The brightest taillights will have more LEDs. Depending on the lights and mode, some can last up to 400 hours on two AAA batteries. In selecting a taillight, chose one that is bright from behind and also visible from the side.
Most lights attach to the handlebars. This keeps weight off the rider while providing a very secure attachment. For most uses, this is a good arrangement and a must for the heavier dual light systems. However for twisty single track, a helmet mounted light works best — especially as a supplement to a handlebar system. The light can be directed so you are never riding into the dark and is the best choice for nighttime mountain bikers.
PICKING THE RIGHT LIGHT
So…now that we’ve covered a whole bunch of technical stuff about lights, which one do you need? Below are some question to ask yourself, and some considerations to take in before purchasing and using a light.
- Where do you ride?
- Trail: If you’re riding on the trail at night, you’re going to need at the minimum a lighting system with a high lumen output and a broad beam pattern on a helmet mount. If you plan on riding fast, you may also want to add a second light on a handlebar mount with a more focused beam so you can see where you’re going.
- Road (Urban): If you’re riding on the roads in an urban or suburban area, you can probably get away with only safety front and rear lights. The high ambient light in these areas means that it’s more important to be seen than to worry about lighting your way. If you’ll be riding in heavy traffic, you may want to consider adding multiple front and rear lights with different flash patterns to make yourself more visible.
- Road (Rural): If you’ll be riding on some country roads we recommend combining commuter lights and a lighting system. Commuter lights are brighter, so on their flash setting they make you more visible to traffic, while a medium to high power lighting system will help you see where you’re going. Remember, though, you need to stay more visible to motorists, so the more lights you have, the better.
- When do you ride?
- Afternoon: For mountain bikers, you should definitely have your lighting system in your hydration pack, you never know if you’ll get lost or delayed. Road cyclists should also put at least some basic safety lights in their jersey pocket in case the ride goes longer than planned.
- Dawn and Dusk: Use your standard lights. While they may seem unnecessary, remember that the human eye does not do well in low-light conditions—especially at dawn or dusk when the eye has trouble focusing on moving objects. For mountain bikers, this can mean you may miss obstructions or small obstacles that could cause a crash, so use your lighting system on its “low” setting. And for road cyclists and commuters, tired motorists may not be able to see you as clearly as you can see them, so using flashing safety or commmuter lights will make you more visible to traffic.
- Night: Use your full light set up on regular power. For road cyclists, this means having all your lights on. For mountain bikers and commuters, this means having your lights on full power setting.