We reveal all you need to know about bike lights and how you can be sure you can see and be seen while riding at night.
As summer turns to autumn, and then quickly to winter, it’s vital that cyclists use bike lights. In fact, it’s illegal to cycle on UK roads after dark without lights.
There are many different bike lights to choose from and across a wide price range. They also come in a variety of sizes, shapes and outputs. There are also many different looks, fittings and batteries. To help you to decide which bike lights are the right ones for you we’ve complied a list of 16 commonly asked questions – and some straightforward answers.
Q: Can I swap my front and rear lights for better effect?
A: We all want to stand out on our bikes at night but you will be breaking the law if you have red on the front and white on the back, or a mixture of these. Legally, cyclists must use a white beam light at the front of their bikes and a red for the back. It’s similar to a car and it allows other road users to work out whether you are coming or going. (You should also have a red reflector at the rear of your bike.)
Q: A bike reflector? But I took that off my bike because it looked ugly.
A: It’s the law although it’s fair to say it’s rare to be challenged by a passing police officer on reflectors. However, if you are in an accident this might be regarded as contributory negligence. According to the law you need a rear reflector mounted on the bike and amber reflectors on each of the four sides of your pedals.
Q: Is there a limit to the number of lights I can use?
A: The more lights you have the greater your chances of being seen. If you sport too many lights, however, you might be confused for a Christmas tree. It’s important to use commonsense. 🙂
Q: Should I ride with lights during the day?
A: It may seem counterintuitive but studies have shown that riding with lights on during daylight can dramatically improve visibility even in bright conditions. The most effective lights for day riding are ones that have a sporadic flash mode, which is great for catching peoples attention from a distance.
Q: Where would you suggest I add smaller lights for the best effect?
A: It’s fairly common to see lights attached to rucksacks, spokes and helmets. Some helmet manufacturers and cycle clothing designers also add lights as standard to equipment.
Q: Every bike light I look at has a different lumens rating. What does it all mean?
A: Lumens is used to describe the brightness of a light. That is, the total volume of light emitted. The higher the lumens number the greater the light output in general. However, the lumens output will vary according to the beam of a light. So a more intense output will be created on a smaller, spotlight beam, while the wider a beam the less intense the lumens will be.
Lumen output is also affected by the conditions, so it will be duller in foggy weather, for example.
Q: So brighter is better?
A: Well, it’s not as simple as that. Bright lights are great but they can also be a huge drain on batteries. You could choose to run a bright light on a lower setting and then flick the switch for more beam when you come to a very dark section of road or trail.
And a bright light set to its highest level could actually be blinding in some conditions. You should experiment with where you place the front headlamp, for example lower on the front handlebars, rather than higher.
Bike lights with greater lumens output are usually more expensive, too, so you need you take that into account when choosing your bike lights.
Q: Should I choose different lumens for different cycling activities?
A: If you want to see your way ahead with a headlight, such as for mountain biking on dark trails or cycling on unlit country roads, you’ll need a super bright light so you should look for the greatest lumens rating you can afford. Remember to also take into account the beam pattern and mounting system.
A lower lumens rating will be fine for being seen on street lit roads but in general the higher the lumens the better the light output.
Q: I have found a great value bike light but it’s run on four AA cell batteries.
A: There is nothing wrong with cell batteries for bike lights but if you can run them on rechargeable batteries it’s usually more economical and definitely more environmentally friendly.
Better still, are lights that can be recharged via a USB port and directly into the light unit itself. These tend to be smaller, lighter and more efficient.
A: How long will the batteries last?
A: This is a bit of a “how long is a piece of string” question. Battery life depends on the lumens output of your lights, which mode they’re used in and even the outside temperature. Batteries can quickly run out of charge if you push them too hard.
It’s worth carrying spare batteries or a mobile power charger that allows you to recharge batteries in an emergency. Lights that have a battery life indicator are vital if you plan to be out in remote locations at night.
Q: I think I understand what lumens are now, but what is LED?
A: LED stands for Light Emitting Diode. This is a solid state semi-conductor that glows brightly when a current is passed through it. It’s a new style of “bulb” – pretty much standard in all lighting these days – as compared to the traditional incandescent bulb.
Q: And what about flashing lights? Are these legal?
A: In times gone by, flashing lights were not allowed but thanks to the 2005 RVLR amendment it finally became legal to have a flashing light on a pedal cycle, provided it flashes between 60 and 240 times per minute (1 – 4Hz).
It is however useful to note that flashing lights can be less effective when they are used on their own compared to a solid light and a flashing light in combination. For daytime riding however, lights with a sporadic flash are best.
Q: The small print on my new bike light says to use it in conjunction with a British Standard legal light?
A: It’s fair to say that some aspects of the British Standards for bike lights are still incredibly outdated, turning a blind eye to the technology changes (including today’s widespread use of LEDs) of recent years, which has led to more powerful and, arguably, safer lights than ever.
Still, it’s the brand’s responsibility to point towards the law and we would always recommend to carry a backup light but BS legal lights, ironically, are extremely hard to come by these days.
(For more detail on the legislation, please check this link)
Q: Does size matter?
A: There are some small lights with a very powerful output and some larger lights that have a weak beam. And there are all the lights in between.
If you prefer a small but brighter light you may need to spend more. But as technology improves and lights become smaller and lighter, the average bike light will be smaller, lighter and brighter.
Q: Will all lights fit my bike?
A: Most lights come with a range of fittings to accommodate various handlebar and seat post sizes but in some exceptional cases they might not fit.
You should check the circumference of you handlebars and seat post before buying a new light. There is nothing worse than a light that wobbles about while cycling or, worse still, a new and shiny light that can’t be fitted to your particular style of bike.
Q: I’ve seen lights that have remote controls. How cool!
Some lights simply switch on and off. Others have a range of flashing modes. There are also lights that can be run with a reduced beam or a wider beam and then there are lights with a remote control. What you choose will depend on what you plan to use your lights for and how much variation you require.
Q: Can you tell me where I put my lights after last winter? I can’t find them anywhere.
A: Ha, ha! Sadly not. But if you don’t know where they are, or where your “safe place” is, and you’ve asked your long-suffering partner where they might be and they don’t know then it’s time to buy some new lights. The choice is huge! 🙂