You should choose your lights based on five criteria: the type of light, the lighting mode, the power supply, the fixing and the light's power.
Different Types of Bike Lights
A rear light is different to a front light for one very simple reason: they are designed to perform different roles. There are four main types of light depending on what you need.
Rear lights make you visible to other road users behind you.
Two-colour lights (or 2-in-1: front/rear lights) need just one light to perform either of the normal bike light functions. Cyclists can switch these lights between white and red depending on what they need.
These lighting kits have two lights so they can always perform both functions at the same time.
Front lights are designed to light up the road in front of you, and warn drivers coming towards you that you are there. Some lights can be fixed to your helmet. If you go for this option, it may be a good idea to also have a light on the handlebars to provide a permanent, efficient way of lighting up the road.
The Lighting Mode
Some lights come with just fixed mode, while others can be fixed or flashing.
Fixed mode has the advantage of guaranteeing continuous lighting that helps you see the road (to a greater or lesser extent depending on the power of the light). The compromise is that this type of light doesn't attract other road users' attention as much.
Flashing mode (at the front or back) makes you very visible to other road users but doesn't let you see where you're going. The advantage of flashing mode is that the battery will last longer than a fixed light.
The Power Supply
The power supply you choose will mostly depend on how often you use your light.
Bike lights that rely on a rechargeable battery are ideal for regular, daily journeys. Some of them use a USB port so that they can be easily recharged at home or at work.
Battery-powered lights are easy to use but only suitable for less regular journeys. Besides a limited battery life, they have a bigger environmental impact. Consider using rechargeable batteries to reduce this impact!
The Light's Power
You should choose the power of your lights based on the environment in which you will be cycling.
At B’TWIN, we judge a light's power based on the distance at which you are visible and the distance ahead of you that the light illuminates.
This ability to be seen is scored on a scale from 1 to 10. This is the B’VISIBLE score, which is derived from standardised tests. A score of 5 indicates the ability to be seen from 100 m away (which is further than the stopping distance of a car in town). A score of 10 indicates visibility from 1500 m away.