Whether it’s to guide you down a dark country road or to stand out in the mayhem of a bustling city centre, you’ll want the right lights for the job.

Those unusually long British summer days mean that many of us rarely ever need to think about lights on a bike from May through August. Traditionally it has only been the few hardy souls among us, the year-round commuters and the competitive cyclists clocking up the winter base miles who need to think seriously about lights.

With more and more people taking up cycling, it’s important that we are all aware of the importance of proper lighting.

When the clocks change by the end of October, it may well be dark by the time most people finish work. For the safety of all road users, it is important that we make the effort to select the best lights for our needs.

Therefore, you'll need to make sure you have the right type of front lights and back lights so you're easily identifiable to motorists, pedestrians and other cyclists. These vary from USB rechargeable lights to battery-powered lights - all of which will emit different levels of light (measured in lumens).

The law regarding bike lights

In the UK, it's illegal to cycle on any public road in the dark without lights and reflectors. If you're not sure which lights and reflectors you should be using for your bike, it's a good idea to check out the UK's Road Vehicles Lighting Regulations.

A quick summary of what’s legally required

The Road Vehicles Lighting Regulations states that you must use lights and reflectors on a pedal cycle when you're riding after sunset or before sunrise. These must be in good working order - and as long as they're clean and do the job, you'll be fine in the eyes of the law. However, to ensure maximum visibility and safety you’ll want to go a step further and find the right lights based on your needs.

The dangers of cycling at night without a light

Without a bike light, you’re at serious risk of not being seen by other road users. Drivers are human, some speed and become distracted. Accidents can happen. Without a light you tend to blend into the surroundings, making the chances of a mishap all the more likely. Outside of well-lit town and city centres, you’ll want more powerful lights on those dark country roads. Potholes and uneven surfaces can easily throw you off.

Choosing the right lights for your bike

The first thing to consider is the lumen rating of your lights..

What are lumens?

A lumen is a unit for measuring how bright a light appears to our eyes. The higher the lumen value, the brighter the light. Some lights can be as dim as 5 lumens, while bright sunlight can have an illuminance of 100,000 lumen per square metre!

A bike's rear light will emit anywhere from 5 to 100 lumen, while a front light can be as dim as 10 lumen or up to several thousand lumens.

How many lumens do you need?

This will all depend on when and where you cycle. If you frequently ride in rural areas or dark paths at night, you’ll need a brighter front light. On a well-lit urban road, however, a very bright light could distract other road users, so it would be sensible to go for something with lower lumen.

Don’t dazzle other road users!

In London, there has been talk of a 'dazzling bike light epidemic', with some cyclists resorting to lights as bright as 1600 lumen - which in a reasonably lit area can actually cause temporary blindness to other road users.

Appropriate lumen range for different environments:

Cities: 20-200 lumen

Rural areas: 200-800 lumen

Remote trails: 800+ lumen

Fitting your lights

Normally, you'll fit battery-powered front lights just above the handlebars, although you may prefer to fit them below so you have more space. Fit your back lights to the seatpost, although make sure they're not blocked by any clothing or baggage.

You can fit rear dynamo lights on the rear carrier/mudguard, while dynamo lights must be securely bolted to the fork-crown to keep the wires away from the handlebars.

Batteries for your bike lights

Always make sure your light battery is fully charged, even if you’re only planning a short journey. Also, for regular cyclists, it may be worth carrying a spare, as it’s inevitable that your light will suddenly decide to stop working just when you need it most.

An advantage of running a USB rechargeable light is that you can recharge it anywhere where you can connect it to a USB port - and the battery will last for several hours. However, battery-powered lights are generally cheaper and have a much longer continuous/flashing mode - so you won't need to charge them as frequently.

The winter days may be short on light, but unless you’re short on motivation, there’s no need to stop cycling. The hardy among us can safely enjoy the benefits of winter commutes and training rides by mounting suitable lights.