If you’re planning to ride after dark, you need to have a good quality set of lights. In most places, it’s a legal requirement to have a white light at the front and a red and the rear, and it’s dangerous to ride without them after the sun has set.
Most cyclists will regularly ride after dark in the fall and winter months, making bike lights an essential piece of kit, but daytime lights are growing in popularity because they help you to be seen out on the road, even in bright sunlight.
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Sun in the eyes is often cited by motorists as a reason for not spotting a more vulnerable road user, a factor that can be negated by a set of bike lights switched on during the day to contrast the rider against the bright backdrop.
We’ve got more on everything you need to know when choosing a bike light below, but first here are some of our recommendations for lights worth looking into.
With each product is a ‘Buy Now’ link. If you click on this then we may receive a small amount of money from the retailer when you purchase the item. This doesn’t affect the amount you pay.
Our pick of the best front bike lights
Front lights are classified as ‘seeing’ lights or ‘be seen’ lights.
Be seen lights make you more conspicuous and are designed for use on lit roads. In this case, 100 lumens is a good starting point – but 300+ will let you see more of the road ahead.
Seeing lights highlight the road in front of you, and are designed for cyclists who want to ride unlit roads. The brightness of bike lights is measured in lumens, and you’ll need anything from 700 lumens, though 1000+ lets you ride closer to your summer speed as such a beam gives you more foresight.
‘Be seen’ blinker: Beryl Pixel Dual Light
Read more: Beryl Pixel Dual light review (9/10)
The Beryl Pixel Dual lights are pocketable, lightweight lights that’ll keep you safe on well-lit commutes home when you don’t want to be lugging around heavier options.
‘Be seen’ blinker: See.Sense Ace lightset
Read more: See.Sense ACE lightset review
Admittedly, not a cheap blinker set. However, the See.Sense lights have a trick or two up their sleeve. Firstly, they get brighter as the rider gets faster, approaches intersections, or swerves to avoid obstacles like potholes. Secondly, they’re part of a trial project where data from the lights is collected, anonymized and aggregated — helping to inform planning decisions for the future.
The lights charge via USB, put out 120 lumens max, and weigh around 36g per light.
UK buy now: See.Sense Ace lightset at Amazon UK for £79.99
US buy now: See.Sense Ace slightest at Amazon USA for $49.99
‘Be seen’ blinker: Knog Light Pop II Front light
This 60 lumen light offers just enough brightness to ensure you’re marked out on the road, and committed commuters might use it as a ‘back up’. The design keeps it simple with AA batteries and it offers 180-degree side visibility.
‘Be seen’ from further away: Exposure Sirius MK9 DayBright
Read more: Exposure Switch front light review
The Exposure Switch is the brand’s dedicated commuter light providing all the illumination you need to see and be seen while in an urban environment. It puts out an impressive 850 lumens though you’ll be pretty visible, but the wide beam shape isn’t particularly useful for seeing the road ahead.
‘Be seen’ from further away: Knog PWR Rider front light
Read more: Knog PWR rider review
Part of a comprehensive lineup from Knog, this model will shine at 450 lumens for two hours, or up to 90 hours on the low energy flash setting.
The ‘bonus’ feature here though is that the Knog PWR can be used to charge up other devices, thanks to a hidden USB port, meaning you can breathe life back into your dead phone so you can make an emergency call, or your cycling computer so you don’t lose a ride.
UK buy now: Knog PWR rider at Wiggle for £49.90
US buy now: Knog PWR rider at Jenson USA for $69.99
‘Seeing light’ for slower rides: Cateye Volt 800 front light
Read more: Cateye Volt 800 front light review
At 800 lumens, this is just enough to commute on unlit roads and see where you’re going. It’s not so bright that it will illuminate the road just like a car headlight would, so you’ll need to adjust your speed accordingly. There’s six different modes and the battery will last between 2 to 80 hours depending which you run it on, taking 5 to 9 hours to fully charge.
‘Seeing light’ for fast rides: Exposure Toro MK12 front bike light
Read more: Exposure Toro MK8 review
Designed with cross country mountain biking in mind, this light puts out a whopping 3300 lumens. Running it at full power might not make you popular on a group ride, but of course, you can use a lower mode, but tackling the unlit back roads alone you’ll have excellent visibility. Just make sure you lower the mode for oncoming vehicles.
The beam is tight and focused – whilst Exposure’s more road-going offerings (like the Joystick) will spread it out more. The run time is two hours and this one weighs in at only 236g.
UK buy now: Exposure Toro MK12 at Tweeks Cycles for £305
Value ‘seeing light’ for fast rides: Lezyne Lite Drive 1000XL
Lezyne’s big lumen light range has come on in leaps and bounds in recent years. This model puts out 1000 lumens and weighs 153g. Battery life is up to 87 hours, though be aware that comes down to 1.5 hours on high power mode. A full charge takes 4 hours, and the aluminum unit is attached to the handlebars with an all-in-one mount and rubberized strap.
UK buy now: Lezyne Lite Drive 1000xl at Wiggle for £61.60
US buy now: Lezyne Lite Drive 1000xl at Amazon for $69.99
Our pick of the best rear bike lights
Rear lights are a little simpler to classify – they need to make you visible from behind, should have a battery life you can rely on and easy charging method. Here’s five we recommend…
Lezyne KTV Pro rear light
Read more: Lezyne Pro KTV review (as part of set)
A bright 75 lumen rear which offers a variety of modes, including a daytime option.
Charging is via an inbuilt USB stick, you just whip the end off and plug it in. The light uses a rubber band for mounting and can fit aero or round seatposts, though we did find it suited aero versions better.
UK buy now: Lezyne KTV Pro rear light at Wiggle for £17.60
Cateye Rapid X3 rear light
Read more: Cateye Rapid X3 rear light review
Plenty of modes and 150 lumens on the highest output make the Cateye Rapid X3 very competent rear light. We like that it uses two LEDs which makes the flash setting seem particularly bright and that it automatically goes into a reduced ‘low battery’ mode when it’s running out of juice. Charging time takes about 3 hours.
UK buy now: Cateye Rapid X3 rear light at Tredz for £41.99
Lezyne Laser Drive rear light
Read more: Lezyne Laser Drive rear light review
At over $50, this is quite a pricey option – but it’s got a unique party trick. The 250-lumen rear bike light also incorporates laser beams which can be displayed either side of the cyclist, designed to reduce the number of close passes cyclists experience. The mount is compatible with both round and aero seat posts, too.
Bontrager Flare RT
Read more: Bongrater Flare RT
Don’t be fooled by the Bontrager Flare RT’s compact size, this miniature tail light backs the punch of a flashbang. The LED inside only outputs 90-lumens, but the optics built into the lens focus the beam in such a way that the Flare RT can be seen from up to 2km / 1.2mi away. ANT+ connectivity means it can be connected to Garmin computers to show battery status and for control, and an integrated ambient light sensor adjusts brightness for maximum visibility.
UK Buy now: Bontrager Flare RT from Trek Bikes for £44.99
US Buy now: Bontrager Flare RT from Trek bikes for $59.99
Garmin Varia RTL515
Garmin’s Varia RTL515 has four light modes, 65-lumens under the hood, and has a viewing angle of up to 220-degrees, but that’s not what sets this light apart.
Hidden inside this sleek looking taillight is a rear-facing radar which can pick up cars from up to 140m / 459ft away, and when connected to a Garmin or Wahoo head unit, alerts you to and tracks cars as they approach. It may sound like a gimmick, but in our experience, it is surprisingly accurate, and often picks up cars before our ears do.
UK buy now: Garmin Varia RTL515 from Halfords for £169
Cycliq Fly6 rear camera bike light
Read more: Cycliq Fly6 review
Finally something a little bit different, not only is the Cycliq Fly6 a 30 lumen rear light, but it is also a camera capable of shooting HD footage of what’s going on behind you. A useful feature is that if the built-in accelerometer detects that you’ve been in an accident it will automatically keep the footage, providing you with evidence to give to the authorities.
UK buy now: Cycliq Fly6 at Amazon for £167.99
US buy now: Cycliq Fly 6 at Pro Bike Kit USA for $189.49
Front bike lights: what do you need to consider?
We’ll look at specialist lighting options in a moment, but for now, let’s assume you’re a road rider or commuter who wants to see and been seen when the sun sets. What do you need to consider when buying your lights?
Most modern cycle lights use LEDs rather than old-school bulbs, and such has been the advancement of technology, these can be blindingly bright.
Of course, light power is an important part of your buying criteria, but don’t let that be the be-all and end-all. Beam shape and the effect of the light lens can make a huge difference — we’ve seen lights of supposedly lesser power trounce rivals when it comes to real-world performance.
Even if you plan on using a light to see, it will still perform the double duty of helping you to be seen by other road users.
If you’ll be riding on lit roads, you may find the need for an ultra-bright constant beam is unnecessary and a flash function at the front is perfectly adequate.
Bike lights and the law: UK
New bikes are sold with reflectors and many people dress in high visibility clothing, which are good additions but in no way make up for a bike with no lights. Bicycle mounted illumination is essential for safety and to keep you on the right side of the law. A decent set of bike lights can be the difference between riding home safely or not getting there at all.
In the UK, law regarding bike lights is governed by the Road Vehicles Lighting Regulations, first published in 1989 but amended six times since, which says that as well as your pedal reflectors and rear reflectors (the side and front reflectors aren’t actually a legal necessity) night-riders will also need lights front and back.
The lights have to be mounted on the bike centrally or to the offside, positioned up to 1.5m from the ground, and conform to British Safety or EC standards.
Both front or rear lights can be flashers, but if so they must emit at least four candela. “But bike lights tend to be rated in lumens or Watts, what’s a candela?” we hear you cry.
It’s not a particularly easy subject to explain, and they’re not directly convertible units. But simply put: as long as you buy decent quality bike lights, fit them properly, and remember to switch them on, the law shouldn’t be a problem.
Bike lights and the law: US
In the US, the law requires riders to have both active and passive lighting — active lighting is well…lights, while passive lighting are things like reflectors and reflective clothing.
The exact wording of the laws varies from state to state, but the summation of it all is that between sunset and sunrise or in conditions of ‘limited visibility’ you must have a white light pointing forwards, and a red light pointing backward.
Lumens and power
Lumens are used by the bike industry to measure the power of a light: a lumen is a unit of visible light. Since modern LEDs require far less energy, expressing their power in watts — which tells you how much energy they consume rather than how much light they produce — is redundant. For comparison’s sake, a 100W incandescent bulb emits 1600 lumens.
The more you pay, the more lumens you get, but lumens burn up charge, meaning that if you want to run a high-lumen light for a long period of time it will need a big battery.
For road riding on unlit back streets, you need a ‘seeing’ light. This needs to be at least 700 lumens, though to ride fast like you would in the summer then 1000+ lumens is a safer bet as you’ll have longer to anticipate obstacles like pot holes.
To be seen when riding on lit roads, 100 lumens is a good benchmark, but 300+ will show you a little more of what’s going on at ground level ahead of you. At the rear, anything from 20 to 100 lumens is plenty.
Battery life and charging
For your rear light, the flash function is ideal. But if you’re a bike commuter, with both front and rear lights also consider how effective the lamp is in terms of side lighting, as this will make you more visible from more angles and help avoid the “sorry, I didn’t see you” excuse from a turning vehicle.
It’s still generally a case of the brighter the better, but you also need to consider other qualities that will make your life easier. Look to see how many flash settings the light has; what the run times will be on a single charge or one set of batteries; and see if it has a rechargeable power source.
In this case, check if it needs its own special charger or if it can be recharged via USB, which aids convenience immensely. Some lights even have a helpful gauge showing how much power they have left.
Bike light mounts
The last consideration is mounting. Smaller bike lights may be simply mounted using a rubber or silicone strap, whereas big lamps — especially front lights — may require a fixed bracket. Truly powerful front lights may even feature an external battery pack that will also need to be accommodated on the bike.
In any case, if you’re planning to leave your bike parked up in public for any length of time, make sure your lamps can be easily removed.
Rear bike lights: what do you need to consider?
Though the amount of power you’ll need for your front light will vary depending upon where you’re riding, no cyclist should be without an adequate rear bike light. Rear bike lights will usually omit around 30 lumens or more, and generally have several modes: steady light, flashing, or a combination between the two. All options are safe and legal, but a flashing mode will usually help to save battery life and attract more attention.
Recently we have been introduced to the idea of using a rear bike light even in the day time, because it will help drivers pick you out from behind. It’s also a sensible idea to double up on rear lights. Though it’s unlikely, you won’t be quite so aware if your rear bike light fails as you would be in the case of a front beam, so having a back-up fitted can provide extra security and peace of mind.
Back-up bike lights, helmet-mounted bike lights and extra brightness
The typical bike commuter on urban streets will only need a relatively simple set of front and rear lights. There’s still every reason to buy the best you can afford, and even double up with an extra set of cheap emergency-only flashers front and back. But if you’ll be riding off-road or on unlit back roads, you really do need to go for the bigger, more powerful lamps with wider beams.
To augment their bike-mounted tourch, many riders also opt for helmet-mounted lights. These can be very effective and have the added benefit of directing the light wherever you are looking. However, these should be in addition to those on the bike, and not your only source of illumination.
Another sensible option is the dynamo light. This uses a compatible hub or wheel-rubbing bottle dynamo to convert your forward motion into electricity which then powers the light — so no need for batteries. Bottle dynamos can be disengaged in daylight hours so they don’t drag unnecessarily, and at night means you’ll never need to worry about run times or recharging again.
Super safe accessories
Night riding isn’t just about illumination. In recent years a whole industry of associated safety accessories has come about.
For example, the Blaze laser light combines a high-powered rechargeable front lamp with a warning image of a cyclist projected by a built-in laser onto the road ahead of you. Similarly, the Xfire Bikelane looks just like a typical LED rear light, but it uses lasers to project virtual bike lane markings either side of you.
There are some smart options out there designed to improve your safety. For example, See.Sense lights are clever front and rear lamps that use inbuilt sensor technology to flash brighter and faster when cyclists are in potentially dangerous scenarios and Garmin’s Varia radars will literally make you aware of and track cars as they approach.
There are more innovative products appearing all the time, so do enjoy exploring the world of cycle lighting. Just remember, the basic rules haven’t changed: be safe, be seen.