Bike lights explained

Cycling safety is of utmost importance, especially when riding during low-light conditions or at night. Choosing the right bike lights is crucial for enhancing visibility and ensuring your safety on the road. This article will provide an overview of front and rear lights, highlighting the differences between battery-operated lights, rechargeable lights, and dynamo lights. Additionally, we will explore the concepts of lumens and lux, shedding light on their distinctions and significance.

Modern bicycle lights are LEDs because they are bright and use low energy.

modern bike lights are LED

Types of bike lights by their position

The position of your lights matters because it affects how well others can see you. Different positions serve different purposes and help improve your visibility from different angles.

Front Lights

These lights are white in colour and are usually mounted on the front of the bicycle, either on the handlebars or on the top of the fork. Their job is to illuminate the path ahead. They provide visibility for the rider and help alert oncoming traffic.

front bike lights are usually fitted on the handlebars

Rear Lights

They are positioned at the back of the bicycle and are usually mounted on the seatpost or bike rack. They emit a red beam and make the rider more visible to vehicles approaching from behind. 

rear bike lights are usually attached to the seatpost

Types of bike lights by power source

Understanding the different types of bicycle lights based on their power source can help you make the correct decision about which option suits your riding. From battery-operated lights to rechargeable lights and dynamo lights, each power source has its own advantages and considerations.

Battery-Operated Bike Lights 

battery operated bike lights

They typically run on replaceable batteries ( such as AA, AAA, or CR2032) and feature different flashing patterns to increase visibility and attract attention. These types of lights are suitable for commuting on well-lit streets and make the rider be seen by others. They are more affordable and easy to install. However, they may require frequent battery replacements, leading to additional costs over time and having a negative impact on the environment.

Rechargeable Bike Lights

Rechargeable lights have gained significant popularity in recent years. They are equipped with built-in batteries that can be recharged using any device with a USB port. 

rechargeable bike lights can be charged with any USB port

Many rechargeable lights offer multiple brightness settings, allowing you to adjust the intensity of the light based on your needs and conserve battery life. 

More expensive and powerful ones are also suitable to illuminate the path ahead on unlit roads or trails. Be aware that using bright bicycle light settings on roads and paths where they can blind other road users is unsafe and compromises their visibility. 

Rechargeable batteries usually offer higher brightness levels and longer runtimes compared to lights powered by disposable batteries. However, they have a limited lifespan and when the battery stops working they have to be disposed of.

Dynamo Lights

dynamo hub bike lights

Dynamo lights are powered by a small generator that is integrated into the bicycle’s wheel hub. As the wheel rotates, the generator produces electricity, providing a continuous source of power for the lights. 

small generator in the wheel hub

This eliminates the need for batteries or charging, ensuring reliable illumination without worrying about running out of power. Most modern dynamo lights on a bike are equipped with a little battery that is charged when moving and used to keep the light on for a few minutes when stopped. This can be useful for example when stopping at traffic lights.  

small battery in the dynamo hub bike lights

Installing dynamo lights can be more involved compared to battery-operated lights and requires basic electrical knowledge. It requires installing a dynamo hub, and compatible lights, and connecting them with wires.

parts required to fit dynamo light system

Also, dynamo hubs create a slight resistance when generating electricity, which can result in a small amount of drag while cycling.

Understanding Lumens and Lux 

When comparing bicycle lights, you will often come across the terms “lumens” and “lux.” These measurements help determine the brightness and intensity of bike lights. Here’s what you need to know about each.


Light intensity measured in lumens is the total amount of visible light emitted in this case by a bicyce light.

lumen as a total amount of visible light

A higher lumen value indicates a brighter light.

different amount of lumens in bike lights

The lumen output for bicycle lights can vary between 5 lumen and thousands of lumen. In comparison a candle emits around 15 lumen, car lights emit around 1000 lumen and the headlights of a commercial airliner can produce over 100,000 lumens. 

If you mostly ride on well-lit streets with streetlights or other sources of illumination, a bike light with a range of 50 to 200 lumens may be sufficient. 

When riding on unlit streets or areas with poor lighting, it is recommended to have a brighter light with a range of 600 or more lumens to ensure good visibility.


Lux measures the amount of light that falls on a surface area. It indicates the intensity or brightness of the light in a specific area. Lux values are influenced by factors such as the distance between the light source and the illuminated object.

Higher lux values generally indicate brighter and more powerful lights that can provide better visibility at longer distances. On well-lit streets, a bike light with an illuminance of around 20-50 lux can be sufficient. When riding in unlit or poorly lit areas, such as trails a brighter light with an illuminance of 200 lux or higher is recommended to illuminate the road ahead.

Making the right decision when choosing bike lights

Choosing the appropriate lights for your bike depends on various factors, including the riding environment and personal preferences. LED lights are a popular choice due to their brightness and energy efficiency. It’s important to consider the specific needs and conditions of your cycling journeys when selecting bike lights.

Remember, prioritizing safety should be the primary focus when it comes to bicycle lights. Investing in high-quality lights that provide adequate visibility and illumination can greatly enhance your safety on the road. Whether you’re riding during dawn, dusk, or at night, ensure that your bike lights are in good working condition and properly installed. Stay safe and enjoy your rides with well-equipped lights.

Want to stay visible while cycling in the dark? Besides using bicycle lights, there are other tips to enhance your visibility. Check out these tips for a safer and more visible nighttime ride!

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