The best rear bike lights 2018: LED tail lights to keep you safe on the roads

Prevent rear-end shunt unpleasantness with these affordable red blinkers

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Tis the season of mellow fruitfulness and misty mornings... and danger on the roads! Not wanting to be alarmist, the nights are drawing in, mornings are dark, drivers are often sleepy and visibility is often poor on those dull, overcast days. 

It's not all gloom and (potential) doom, though, as we've rounded up this bunch of exemplary, red-hued blinkers to light up your backside and make you fully visible from behind. 

What is the best rear light for your bike?

For sheer weight of features, it is difficult to top the Garmin Varia Radar and the See.Sense ICON+, but it's the latter that we were most impressed with.

At 250 lumens, it is brilliantly bright, but it also justifies its lofty price tag with a great set of smart features. A smartphones app allows you to check battery level, change from flashing to constant, customise brightness runtime settings, and control multiple ICON's at once.

An automatic crash detection function alerts a dedicated contact if it senses a slam, and the ICON+ can even harness the power of  your mobile's GPS to flash brighter at busy roundabouts and road junctions.

How to buy and fit rear bicycle lights

Rear bike lights are all about road safety – making yourself visible to other road users, especially motorists. In contrast, a powerful front bicycle light is, at least in part, for illuminating the road ahead. 

It's a very good idea to invest in something bright, red and preferably flashing, in order to attract the right sort of attention. In fact, it's the law – according to UK legislation (the Road Vehicles Lighting, fact fans), it's illegal to cycle on a public road after dark without lights and reflectors. Plastic reflectors on their own are not sufficient. Uh-uh.

Rear cycle lights aren't only needed at night. In low light or fog, cyclists can be pretty much invisible on the road (in particular, the ones who like to look chic in all black), as well as in dappled shade or when the sun is low and in drivers' eyes. 

Fitting rear lights is simple, with most opting for a rubber strap or a simple plastic ratchet system that clamps around the seat post. The rubber strap is our favoured system – it's so brilliantly simple, yet reliable (when done well), that we look back on vintage lights with their elaborate metal and plastic clamping systems and wonder, "what were they thinking of?"

To be on the safe side, some riders even employ two rear lights, so that if one fails or runs out of charge/battery you're not unwittingly left as an invisible black blob. Helmet-mounted lights are another great back-up option as they're more visible than a seatpost light, which can be obscured by overhanging jackets (watch out for that!) or panniers.

Due to the fact a rear light only really has one job – to act as a safety beacon to alert motorists – it doesn't have to be brutally powerful, and you don't want to burn the retinas of the driver behind you at the traffic lights. As a result, they tend to be a lot cheaper than the lumen-heavy front lights, with even the most expensive dipping below £150, and the average being way lower; it's possible to pick up a basic but powerful rear light for less than £20. 

So, in short, there's no excuse for not lighting up. Lumen output isn't as important in rear bike lights as for front lights but it still pays to invest in something that's bright and easily visible by all. The more powerful the light, the more expensive it tends to be and the more battery power it requires, with 100+ lumen units usually featuring a rechargeable battery.

The upside of rechargeables is you don't have to spend a fortune on replacement batteries. Obviously the downside is that you will have to keep on top of charge levels to ensure the light lasts the length of the ride.

Some rear lights are also designed to attach to backpacks or slot into the rear of compatible helmets and these can be handy additional lights to own, as they are mounted much higher than an under-seat light for improved visibility in heavy traffic.

The best rear bike lights, in order

See.Sense ICON+

1. See.Sense ICON+

The best rear bike light with smart features

Specifications
Maximum lumens: 250
Battery life: up to 15 hours
Rechargeable: yes
Reasons to buy
+Smart features+Very bright
Reasons to avoid
-Hard to fault really

Think of the See.Sense ICON+ as a little computer for the back of your bike, rather than a basic bunch of LEDs, as it packs plenty of smart features to justify the above average outlay.

In short, it connects to a smartphone and bespoke app so you get low battery alerts and charge indication to your device, while GPS is used to alter the brightness and flash pattern at busier junctions.

It mounts using a simple tool-less system, and offers up to 15 hours of run time, or 2-3 at the super bright 250 lumen max output. Oh, and it's a theft alarm too – although obviously that requires you to leave the expensive light unit attached to the bike when parked.

That aside, a great light for using both day and night, while the additional smart functionality is a welcome addition.

 Moon Nebula

2. Moon Nebula

Best inexpensive light

Specifications
Maximum lumens: 180
Battery life: 20+hrs
Rechargeable: yes
Reasons to buy
+Lightweight+Cool design+Maximum visual impact
Reasons to avoid
-Possible mounting issues

This neat little package arguably offers too much light for a rear light, which will only ever be a problem for those regularly riding in groups, but the Moon Nebula's super-bright LEDs are perfect for riders who want to alert fellow motorists to their presence.

A day flash mode gives a lower output to preserve battery levels but still affords good visibility, while the flashing night mode bangs out the maximum 180 lumens.

The light's long, thin shape might not fit every mounting requirement, although there are plenty of mounting options included in the box so you will certainly find somewhere for it.

Lezyne Strip Drive Pro Y11

3. Lezyne Strip Drive Pro Y11

Best for daytime use

Specifications
Maximum lumens: 300
Battery life: 20.30hrs
Rechargeable: yes
Reasons to buy
+Stupidly bright+Lots of light modes+Aero design
Reasons to avoid
-Overkill for commuters

Maximum power and brightness is achieved in the Lezyne Strip Drive Pro, thanks to five, ultra-high output LEDs stacked into one retina-scorching package.

A Mode Memory function returns to the selected mode even after turning the unit off and nine combined lumen and flash modes, including the extremely visible 300-Lumen Daytime Flash mode, make it nice and flexible for most rides. The high power output means battery life isn't the longest though.

It also boasts a unique aero and round post compatible design, so it fits those swanky carbon fibre race bikes that are popular with the evening club ride crowd.

Bontrager Flare RT

4. Bontrager Flare RT

Best non-smart rear bike light

Specifications
Maximum lumens: 65
Battery life: up to 23 hours
Rechargeable: yes
Reasons to buy
+Long battery life+Simple and reliable
Reasons to avoid
-Not as crazily bright as certain rivals

You can tell the Bontrager Flare is built with input from regular cyclists, as it seems to have all bases covered.   

From the large power button, which is easy to operate even with thick winter gloves on, to an integrated charge indication light that makes it easy to see remaining juice levels every time it powers on or off, it's all well thought through.

Mounting is as simple as wrapping it around a seat post but Bontrager also throws in additional clips to attach to it to clothing, bags and helmets.

With some 23 hours of flashing run time, it won't need charging often but when it does, it's as simple as hooking up to a PC, laptop or standard phone charger via the provided USB cable.

Perhaps not as blindingly bright as rivals suggested here, it still produces a solid light output, and is visible both day and night.

Garmin Varia Radar Rear

5. Garmin Varia Radar Rear

Another great 'smart' rear light

Specifications
Maximum lumens: 15
Battery life: up to 5 hours
Rechargeable: yes
Reasons to buy
+Acts as a radar+Plays nice with Garmin products
Reasons to avoid
-Not that bright-Short battery life

A rival to the chart-topping ICON+ this lamp lacks a bit of brightness and battery run time, but makes up for it with very advanced features.

Able to sense traffic approaching from the rear at 140 metres, the Garmin Varia Radar will intelligently alter its brightness and flashing pattern to warn drivers that you're up ahead. Meanwhile, you receive a little audible notification every time vehicles pull up at speed from the rear, as well a visual prompt via compatible Garmin computers – Edge 1000, 820 and 520 – or an optional, slightly bulky radar device.

The computers can even show multiple approaching vehicles, each with relative speed of approach and 'threat level'. Arguably that is more complexity than most people want, but for pitch black country roads, the Radar system could be a life saver. 

Knog Blinder Road R70

6. Knog Blinder Road R70

Best extra-bright rear bike light

Specifications
Maximum lumens: 70
Battery life: up to 20 hours
Rechargeable: yes
Reasons to buy
+Very bright+Solid battery life+Side illumination
Reasons to avoid
-A bit bulky maybe

If ever there was a more honestly-named rear bicycle light than the Knog Blinder, we are yet to come across it. It is officially one of the most eye-wateringly bright rear lights we've crossed paths with and absolutely unavoidable at night thanks to that, and to additional side illumination.

The downside is that it is a little chunky, particularly if you're mounting it to a sleek aero seat post, but it does come with a variety of clamps should that be your choice.

Fashioned from industrial grade silicone and a polycarbonate housing, it's a tough old dog, while the rechargeable Lithium Polymer battery manages a solid four hours on even the brightest flash mode.

Cycliq Fly6

7. Cycliq Fly6

Best rear light with camera (!)

Specifications
Maximum lumens: 30
Battery life: up to 6 hours
Rechargeable: yes
Reasons to buy
+Built-in action camera+Fully weatherproof+Incident detection mode
Reasons to avoid
-Rear footage not usually very useful-No night mode

You can file the Cycliq Fly6 in the same 'Clever Lights' folder as the aforementioned Garmin, as it goes above and beyond its duties of providing a bit of red light in order to adhere to road laws, adding a 720p, 30fps video camera that saves footage to an onboard MicroSD card.

Video captured from the rear of a bicycle probably isn't going to win any Best Picture categories at the Oscars. In fact its only use is likely to be if the worse realy does happen, and you, or your next of kin, need to hold someone accountable for a rear-end shunt.

The Fly6 will record footage if it senses it is tilted more than 30° from horizontal for more than 5 seconds, a bit like a car dashcam, and will continue to record for an hour before shutting down.

Also included: four light setting modes, two flash settings and a maximum high power mode of 30 lumens.

NiteRider Cherrybomb 35

8. NiteRider Cherrybomb 35

Best non-rechargeable rear light

Specifications
Maximum lumens: 35
Battery life: N/A
Rechargeable: No
Reasons to buy
+Great value+Lightweight
Reasons to avoid
-Eats AAA batteries

If you prefer the security of knowing you can just replace the batteries in your lights, when in dire straits, this is a much lighter and far cheaper rear light, which performs just as well as more expensive competitors.

The excellently titled NiteRider Cherrybomb 35 uses a 'multi-directional collimator' (no, we have no idea either) that disperses light to the sides and the rear, eliminating blind spots for approaching vehicles.

Various mounting systems come in the box, meaning it can be attached to the seat post, a rucksack or an item of clothing, and a clever integrated reflector means it's visible to anything with headlights, even when the lamp is switched off.