When you’re new to cycling at night or in winter for the first time, one of the most confusing aspects is often which bike lights you will need. A key term that you will see referenced is lumens. In this guide, we’ll break down what lumens are, how many you need for different types of cycling, and the difference between lights for daytime visibility and those for nighttime riding.
What are Lumens?
Lumens are a measure of the total amount of visible light emitted by a source. In simpler terms, the higher the lumens, the brighter the light. When it comes to bicycle lights, lumens help you determine how visible you’ll be to others and how well you’ll be able to see the path/road ahead.
How Many Lumens Do You Need?
The number of lumens you need depends on the type of cycling you do and the conditions in which you’ll be riding. Here’s a breakdown of the lumens required for different types of cycling:
1. Commuting
Commuting by bike usually involves riding on urban streets, often in areas with streetlights and other ambient lighting. Your primary goal is to be visible to other road users and to have enough light to spot hazards on the road.
- Daylight Running Lights: Even when cycling during the day, having lights on your bike will increase your visibility to others. For daytime running lights, 50-100 lumens are usually sufficient. These lights are designed to make you more noticeable in traffic rather than illuminate the road.
- Night Riding: For night commuting, you’ll need brighter lights to both see and be seen. A front light with 200-500 lumens is usually enough for urban environments, and a rear light with 50-100 lumens will make sure you’re visible from behind.
2. Road Cycling
Road cycling can involve riding at higher speeds on less predictable routes, which means you’ll need brighter lights, especially if you’re riding in rural areas without street lighting.
- Daylight Running Lights: For road cycling during the day, aim for 100-200 lumens to make sure you stand out on busy roads.
- Night Riding: At night, you’ll want a front light with at least 500-1000 lumens to light up the road ahead clearly enough. A Lezyne Micro Drive 800 is a great option to give you enough visibility to enable you to manoeuvre around potholes and street furniture on dark country roads A rear light with 100 lumens or more will ensure that you’re visible from a distance, the Lezyne Strip Drive 300 is a great option and has a 270-degree field of visibility.
3. Mountain Biking
Mountain biking presents a whole new level of lighting needs because of the unpredictable terrain and complete darkness in wooded areas.
- Daylight Running Lights: These aren’t typically necessary for mountain biking, but if your ride will include sections of road then a front and rear light could be useful here. Likewise, if visibility is low due to fog then it’s another way to draw attention to your presence.
- Night Riding: For night mountain biking, you’ll need very powerful lights. A front light with at least 1000-2000 lumens as a minimum is recommended to properly illuminate the trail and spot obstacles. Lights like the Exposure Six Pack offer up to 3,900 lumens giving you near daylight visibility of the trail ahead. Additionally, consider using a helmet-mounted light alongside your handlebar light for better depth perception. It isn’t necessary to have the same power light on your helmet light, your neck will thank you for not carrying a light that is too heavy! A rear light isn’t as critical in mountain biking unless you’re riding in a group or on roads to get to the trail.
Daylight Running Lights vs. Lights for Seeing in the Dark
It’s important to understand the difference between lights designed for daylight running and those meant for night riding.
- Daylight-Running Lights (Lights to be Seen): These lights are all about visibility. They don’t need to be extremely bright but should be noticeable from a distance. Many daylight-running lights have flashing modes that are particularly effective at catching the attention of drivers.
- Lights for Seeing in the Dark (Lights to See): These lights are focused on illuminating your path. The lumen count is much higher, and the beam pattern is designed to light up the road or trail ahead of you without blinding oncoming traffic. Look for lights with a wide beam pattern for road cycling and a more focused beam for mountain biking to see further ahead on the trail.
Final Tips for Choosing Your Bike Lights
- Rechargeable vs. Battery-Powered: Rechargeable lights are more eco-friendly and cost-effective in the long run, but make sure they have enough battery life for your longest rides.
- Mounting Options: Ensure that the lights you choose are easy to mount on your bike and secure enough to stay in place even on bumpy rides. There are various mounting options available if you have an aero seat post or bars and stem or want to cleanly mount below your out-front computer mount.
- Beam Angle and Shape: Some lights allow you to adjust the beam angle or shape. A wider beam is better for general visibility, while a focused beam is ideal for seeing far ahead on unlit roads or trails.
Choosing the right lights is crucial for your safety and enjoyment while cycling. By understanding lumens and selecting the appropriate lights for your riding conditions, you can confidently navigate your rides, whether you’re commuting, road cycling, or hitting the trails at night.
