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Are daytime bike lights a safety essential? Should you get daytime lights?

Trek thinks it's time cyclists started using bike lights even in bright conditions. Do you agree?
This article was originally published in August 2015

Should we ride with a rear light on during the daytime? Or perhaps we should go further and ride with both front and rear lights on even when the sun is shining?

We had a forum topic about this issue on a couple of years ago and what you might call a heated debate when Bontrager announced its Flare R rear light, designed specifically for daytime visibility, earlier in the year.

The reason we’re thinking about it again is that we went to visit Trek last week and the brand is really keen to promote the use of rear lights during the day. It even had the members of Trek Factory Racing ride the prologue of this year’s Tour de France on time trial bikes fitted with the Flare R “to promote awareness of the most important cycling accessory available today”.

Daytime light.jpg

Of course, your cynical side thinks that Trek wants to encourage the use of lights in the daytime because Bontrager, it’s sub-brand, produces that Flare R rear light. It’s simply a way of boosting sales.

Trek acknowledges that, of course, it has an interest in selling lights, but says that the key motivation for launching the Flare R was to keep cyclists safe.

“About two years ago, I was in San Diego, and I’m driving along during the day, and I see a biker, a road cyclist, and he’s got a blinking light on the back of his bike, and I thought, ‘That is a great idea,’” says Trek President John Burke. “The only problem is you could barely see his light.

“When I got back to Trek, I put together a team of engineers, and I said, ‘Listen, what I’d really like to see is a light on the back of a bike that can be seen during the day.’ If we could do that, I think it would significantly enhance the safety of cyclists everywhere.”

The result is the Flare R. Here’s John Burke’s short video presentation on the light.

Trek argues that using a light during the day makes sense because that’s when about 80% of cycling accidents occur.

Well, yeah, says your cynical side, but what percentage of cycling takes place during the day? Maybe that figure simply reflects the number of people on bikes during the daytime compared to the number who ride at night.

Trek also argues that, “Studies on accidents resulting in the fatality of a cyclist show that in 40% of all bicycle vs. car accidents, the victim was struck from behind.”

That statistic is from the US. Put a light on the back of your bike, the argument goes, and you’re less likely to be one of them.

Bontrager Flare R City Tail Light.jpg

“We think products like the Flare R allow a rider to have more control over their safety, putting us in both offensive and defensive positions on the road,” said Trek’s Chris Garrison. “We want to get people talking about increasing their visibility not just at night, but also during the day.”

Chris cites a recent AA-Populous poll as evidence that more cyclist visibility is required. In that poll 91% of drivers said that it’s sometimes hard to see cyclists while driving

John Sullivan, an RAF pilot and keen cyclist, advised in his paper A Fighter Pilot’s Guide to Surviving on the Roads, “Aviation research shows that contrast is the single most important factor in determining the likelihood of acquiring an object visually – this is why military aircraft camouflage is designed to tone down their contrast.

"On the ground, dark coloured vehicles or clothing will result in reduced contrast against most usual backgrounds, and this is why high visibility clothing (for pedestrians, cyclists and motorcyclists) and/or bright lights are so important, in the daytime as well as at night.”

Back at Trek, John Burke says, “People should be able to see you all the time. And when they do, you’re going to have a better riding experience. Get a new Flare R, or buy something else. What I care about is making sure you have a really safe cycling season.”

Exposure Trace TraceR set

Of course, Trek didn’t invent riding with a rear light on during daylight. Some people have always done it and USE, for example, has been advocating it for years. The British lights brand says that its Exposure Flash front light and Flare rear light (yes, the same name as the Bontrager light) are designed specifically for both daytime and nighttime use (you could argue that USE, like Trek, has a vested interest in promoting more bike light use).

Our man Dave says, “I’ve used the Flare R rear light a lot and I’d say it makes a noticeable difference to the passes you get. Drivers tend to give you more space.”

Of course, that’s anecdotal evidence. If anyone knows of any scientific research that has been carried out, we’d be interested in hearing about it.

So, why do so few of us use lights during the daytime? We guess that most people don’t think it’s necessary, although some oppose the idea in principle.

“When a vehicle has lights on it makes any in front or behind without harder to see,” said Simon E in that thread mentioned earlier. “Every vehicle that runs with sidelights/LEDs/DRLs [daytime running lights] in the daytime is furthering the idea that you have to have lights on to be seen, so all the sheeple do the same. Baaaa! This means drivers to look only for lights, not other vehicles or people.

“Lights are NOT needed in daylight, whether on bikes, motorbikes or cars.”

In a comment under our story announcing the launch of the Flare R, McVittees said, “Whilst it is perfectly reasonable to want to run as bright a rear light as possible either during the day to warn cars or at night when riding on unlit country roads, I hate being stuck behind someone who is running a high output rear light at night during my urban commute. I find it distracting and obscures my vision of the road (and thus traffic) ahead.”

andyp said, “[Bontrager are] pouring money into something which will make them more money, not into solving a problem.”

What do you reckon? Do Trek’s arguments convince you that you should use a rear light during the day? Let us know what you think.

Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.

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don simon fbpe | 6 years ago

"Trend Spotting: Should we all be using lights in the daytime?"


willpom @GWRaudax | 4 years ago

I do, but then it is a dynamo set up so I'm actually always training with the increased drag....

On a similar vein though whilst attending a speed awareness course (I hold my hands up I was being naughty in a motor vehicle - no excuse) the instructors mentioned that the number of incidents involving motorcyclists being pulled out on has increased since cars began using daytime running lights as motorcyclists are no longer standing out amoungst the crowd.

Bigfoz | 4 years ago

Company that sells lights wants us to use lights...

That being said, I am generally using daytime lights, but largely because in these days of daytime running lights on everything else on the road, we are even less visible top those that don't look


Xena | 4 years ago

Fuck me , seriously,,,lights In daylight . What about  pedestrians,cars , fucking rowing boats . Roller bladers ,small woodland creatures and how about everyone leaves there lights on at home in daylight all the time. and every council leaves there street lights on .lets not forget the transgenders  do they have to have lights . 

Are some of you fucking blind .  It’s daytime if you can’t fucking see go and get your eyes tested . 

Don’t even entertain  this .  Let’s waste more fucking energy when we have every MSM outlet telling us the world is going to end and we need to conserve energy ( lying cunts)   See the hypocrisy.its all about the Ker ching . 

I live in Iceland ,it’s daylight 24 hours a day “ sell me your lights” “ it’s what the cool cyclists do “ 

This cutting diet is killing me . Ha ha 


dobbo996 | 4 years ago

The problem with daytime lights, like hi-vis and helmets, is that drivers use their non-use to deflect from poor driving. "Yes, I may have pulled out on you without looking're not wearing a helmet....or hi-vis.....your lights are's your fault!". 

If you want to run your lights all day, well, that's up to you. Personally, I only run them in poor light conditions during my commute. Same goes for dressing up like a banana and wearing a thin plastic hat. Been there, done that, doesn't make any difference. If they ain't looking they ain't looking. Want to be safe(r)? Concentrate 100% of the time, look everywhere, don't ride in the gutter, keep away from car doors and heavy vehicles, and treat all other road users, including pedestrians and, regrettably, some people on bicycles, as idiots who will try to kill you.  Works for me.  Take care.

Pedal those squares | 4 years ago
1 like

Yes...why not???? 

The lights today a light and you can recharge them.

They give the drive a "better chance" (WTF LOL) of seeing you....YES THEY SHOULD LOOK WHERE THEY ARE GOING ANYWAY, most do....but as we know, a lot do not!

If the driver then still does not see you and hits you.  Then it is clear they were not paying attention.....I know if they hit you there were not paying attention lights or no lights.....but those lawyers ....well, they are worse than the driver that hit you!!!!!  Then there is the judge...need I say more?

Just pop light weight lights it worth get seriously injuried or worse for that one hit not being a scary very near miss? 

Xenophon2 | 4 years ago
1 like

The main reason why I don't run them in daytime is that I simply don't want to deal with the hassle of constant recharges -all the lights promise limitless autonomy, until you actually use them a couple of months, that is- remembering putting the light back on the bike etc. 

I already wear a fluo helmet, if they don't see that then me thinks I'm screwed anyway.   

Oh, leaving very early and riding home early in the afternoon when traffic is low also helps.  So does making a detour over cycle paths where motorized traffic is prohibited and picking a route with cycle paths that are separate from the motor traffic.  Result:  tranquility, mostly.  And a commute that's double the shortest possible distance but the latter has me ride on a very busy road without bicycle path.

Saintlymark | 4 years ago
1 like

My anecdotal evidence of wearing hi vis is that close passes become more frequent. I don’t see that lights in daylight will make much difference to that. I think visibility on the road by road positioning, and sympathetic riding, is far more effective.

Markh8195 | 4 years ago
1 like

I run a Garmin Varia2 radar rear light which gives me warning of a cars approach and flashes as they get close.

close passes have reduced and I’m much more aware of what’s behind me.

wouldn’t enjoy riding without it now...... ok I would but I would miss it!

Boatsie | 4 years ago

Ditto to no.
Use of common sense should be encouraged.
Using bicycle lanes here, there is much less need, we are spaced from traffic. If on shared roads, particularly in heavy traffic or hilly narrow roads with lots of corners and shade then they'd reduce reactions required by motorists significantly..
Here's to hoping we ain't scumbags when battery discarding becomes. Us Australians helped destroy a beautiful island because we paid rubbish money to landfill a foreign land. Out of sight out of mind kind of thing.
Toxic landfills leach common own Earth.
Recycling has improved.. Batteries are still toxic.
Common sense helps timing of use.
Same with helmets.. But aye. Mate thought I was dead, German Shepard ripped skin off him as he carried me inside and dumped me on mums couch and legged it. Worn a helmet since. Lol. But wouldn't bother if going to visit a near friend if not risking an expiation.

flobble | 4 years ago
1 like

Oh, the irony...

Regurgitated article from 4 years ago (!) uses the title "Trend Spotting"


lbalc | 4 years ago

I use day time front and rear lights. Some comments suggest cars with day time running lights don't stand out if and when every other car is using them too- I don't find this to be the case, especially when it's incredibly sunny out and you go through a shaded section of trees that almost block out all the sun- the contrast from light to dark can leave you as a cyclist being not seen. Having lights on in these shaded areas gives me confidence- and i notice in these conditions the cars with day time running lights. I have to say that Exposure and Cateye with their pulse settings really stand out in the day and the night- solid beam with bright pulse. I recommend them highly above other lights that don't have this setting. Also recommend an air horn! Every pedestrian stops dead when they hear that- and car drivers can't miss the 115Db. So if you survive being hit by a car and get into an argument after using a Cateye with 1200 lumen blast, 2 rear day time lights and an air horn- there's no excuse.


ktache | 4 years ago

I do not do much night-time riding this time of year, but I cannot travel without lights, sometimes things get late and dark.  They are not very heavy these days.  So, I put them on flash if it's sunny, or on (low on the front) if it's particularly grotty.  I thought it was a good idea to keep the batteries being used and recharged every so often anyway, better than leaving them for many months sitting about.

Bobskih | 4 years ago

Lots of valid points

A wide range of thoughts put forward in here and all seem relevant.  As a cyclist/driver we should all be responsible for our actions when out on the open road but things do happen and accidents are unfortunately inevitable.  As a cyclist we are more vulnerable than most and I personally don’t see the harm of making myself more visible whilst I’m cycling around. So if buying lights MAY save my life or prevent injury or worse making a laughing stock of myself as I lay on the floor like an upturned turtle, surely this is a small price to pay.

NZ Vegan Rider | 4 years ago
1 like

No - not when it's bright and sunny. All but the brightest lights will not be seen and if a driver hasn't seen you in those conditions they wouldn't with lights.

Bright clothing in daytime more important = creates a larger, more visable area than lights do. See above “Aviation research shows that contrast is the single most important factor in determining the likelihood of acquiring an object visually" "On the ground, dark coloured vehicles or clothing will result in reduced contrast against most usual backgrounds, and this is why high visibility clothing (for pedestrians, cyclists and motorcyclists) and/or bright lights are so important, in the daytime"

We have fashion victim roadies here who wear all black but lights at both ends thinking that'll make them visable. Bright clothing but no lights is more visable.

See net article called "The theory of big" too. Bigger, brighter area.

In the day time I ride with a Fly6 with the light on the lowest setting. I only have the Fly6 for the video (excellent).

In low light, grey conditions and rain I now ride with lights and think it's a good idea for all riders. A good light will cut through the gloom  3



FatTed | 4 years ago

Marginal Gains, I run front and rear daylights + visible clothing if I have it, don't ride at night

Guyz2010 | 4 years ago
1 like

I use a LED rear flashing light day or night. There is no argument not to in my opinion. Be bright be seen. All assists in an insurance claim

Please no keyboard warriors or trolls to comment thank you.

Markie G | 4 years ago

As a motorcyclist as well as a very keen cyclist I understand the need to be seen. Using lights night and day is a no brainer to me. We as cyclist need to understand this. I'm not saying we need dayglo clothing but a front and rear light helps keep us safer. Surely it makes sense. I don't understand those who say why should I use lights in the daytime, it's down to other road users to look out for us. My motto is "be seen be safe"

spaceyjase | 4 years ago
1 like

I actually like running my lights in the daylight. I’ve got some that are designed for daylight running and it seems to make sense but the cynical side of me feels this is victim blaming. I’ve been hit three times (the last just a few weeks ago!) by drivers who have all admitted to not even looking. It doesn’t matter how visible a rider is if those charged with upholding road safety, requiring testing and licensing, fail to uphold simple observational skills.

graham.mackeen@... | 4 years ago

I've used a rear light at sunset, sunrise & poor light for years, now ride with front light especially in country lanes. 

froze | 4 years ago

The Bontrager Flare R is only 65 lumens, and being an experienced rider and one who does run a rear light (and a strobing front light) when I ride in the daytime I know for a fact that a 65 lumen light is not noticably visible in direct sunlight, heck 65 lumens is the bare minimum for night use!  Even my old tail light that cranked out 90 lumens wasn't visible unless you were about 20 feet behind me then you might see something faint.  I now have a NiteRider Omega 300 lumen tail light, that light is indeed visible from a long ways off. Some tail lights like the cob designed LED's are worse during the day, I have NiteRider Sentra Aero 260 with supposedly 260 lumen, at night it's fantastic (though the light is probably closer to 150 lumens), but during the day the cobs get washed right out.

Pantster | 4 years ago

Yes you should, we all have lights, why wouldn't you use them if they can improve you being seen even slightly. We point fingers at drivers if they don't see us but we all have a responsibility to make roads as safe as possible. Cars now come with daylight running lights so why shouldn't we??

wilbo666 | 3 years ago

Fundementally depends on visability. I used a rear light and hi vis during the daytime this Monday morning due to low visability due to fog out in the fens. During wet riding I also tend to use a light too. Only other times I use daytime lights are CTT events.

squired | 3 years ago

After my brother was put in hospital with a fractured spine after being hit by a car in the middle of the day (sunny, blue skies), while wearing a luminous yellow t-shirt I came to the conclusion that it doesn't matter what you wear or have attached to your bike if the users of the motorised metal boxes around you aren't looking.  Next they will be suggesting that pedestrians get flashing lights too....

Biggus-Dickkus | 3 years ago

Yes, we should be using lights in the daytime, especially at the rear.

wtjs | 3 years ago

No. You would be even more visible with a 5 foot pole sticking up from the rear and covered in lights, but that wouldn't protect me from the death or GBH I'm worried about. They see you, but they don't care because they think that they are ace drivers and that cyclists are like cars. When I was the stationary cyclist waiting to leave Sainsbury's by turning right onto the main road, hit by the car cutting the corner  and proceeding down the wrong side of the road- I had a very bright flashing multiple LED Aldi light mounted on my helmet, and a bright Cateye headlight mounted on the bars. Admittedly it was dark at about 5 pm in mid-DecemberHe hit me with his door mirror, resulting in a cricked neck that lasted a week. He claimed he didn't see me- the reason is that people like that are only looking out for large 4 wheeled vehicles like themselves.

IanGlasgow | 2 years ago
1 like

I run Cycliq cameras all the time, but using the lights shortens the battery life so I only switch the light on when it's dark.

In the winter I have flashing lights front and rear all the time (front: cheap Planet X, rear: See.Sense Ace) but neither is bright enough to be worth bothering with in the summer.

I like the idea of a light with a built in ambient sensor - daylight lights need to be REALLY bright but if you leave them like that they're blinding at night and run the battery down very quickly.

wtjs | 2 years ago
1 like

Still No!

wycombewheeler | 2 years ago
1 like

in the day time possibly

in bright conditions - definitely not

When you can see a cylist from a distance of about half a mile, but their light only becomes obvious at half that it seems pretty pointless. Just a waste of energy and a stick to beat cyclists who arent using lights with.

I'm generally against using lights in the daytime, as I am often trying to conserve my light burn time for when it matters.

Cycloid | 2 years ago

As  cyclists we are competing against the background and other road users to be seen.
New models of cars have been using DRLs since 2011.
We should not have to but are almost forced to use lights in daytime in our own interests.
It is only one small step from no lights to victim blaming




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