The biggest question when buying bicycle lights is - do you need to see or to be seen? The answer to this will tell us which style of lights would be best for you. In this article, we will discuss how the answer to this question dictates which style to choose and the other considerations when choosing your lights.
Need To see
If you are cycling down country roads or trail riding at night, you will require a light that illuminates the area in front of you so you can see where you are going. Bike lights are measured in ‘lumens’ and the higher the number, the brighter the light. For dark roads and paths, we would recommend at least 800 lumens and for trail riding at night, slightly more, at around 1300 lumens (but MTBers will likely need/want more). Just please dip the beam if you are in town or see vehicles approaching.
For dark roads and paths

CatEye AMPP 1100 Rechargeable Front Bike Light
3 hour fast charge from zero to full, 1100 lumens to light up the dark roads and paths and a convenient double-click mode to toggle high mode and your frequently used setting
Moon Rigel Pro Front Light
A max of 1000 lumens at an exceptional price, an adjustable lens for anti-dazzle setting and a 3 hour fast charge to name but a few of the features of this great light.
For MTB trail riding

Exposure Diablo MK13
A whopping 1900 max lumens to light up the darkest trails, incredibly robust CNC engineered aluminium body to deal with any spills and fast tap technology for changing modes on the fly
Lezyne Macro Drive 1300XL
Providing up to 1300 Lumens of power for off road night adventures creating a brighter centre spot and a wide angle pattern.
Need to be seen
If you are cycling in town or on lit roads, you do not require the same number of lumens as the above, the focus here is on visibility. The latest technology means these can be very small, light and can be mounted in various places on you or the bike but still make you visible from a long way off. The more the merrier is also a good way to look at this one, some of our staff wear 3 rear lights in the depths of winter. The extra consideration when choosing “to be seen” lights is, should I go USB rechargeable or replaceable battery?
Battery lights are generally cheaper and if you forget about them, or don't use your bike for a while, the likelihood is that they will still have some charge left. USB rechargeable lights are brighter and more compact and are better for the environment as fewer batteries are discarded but you have to remember to charge them.
Cateye Omni 3 Light Set
Battery powered lights that are simple and relatively inexpensive. If you do not use your bike too often, they will likely still have charge left.
Moon Comet X Rechargeable Light Set
Superb visibility from a very lightweight and compact package. Full charge in 2 hours and a variety of different illumination modes.
Bookman Curve front and rear light
Curve design provides a bright central LED for enhanced visibility from directly behind or in front and two smaller LED's to the sides for more visibility from side on. Quick 2 hour charge from flat to full and easy attach/detach system
There are a lot of excellent lights out there and hopefully this guide will make it a little less of a minefield for you when choosing.