Rear lights: which is best, continuous or flashing?

guerney

Esteemed Pedelecer
Sep 7, 2021
3,680
1,372
You're right it's several orders of magnitude more dangerous than cycling in daylight. If I go out at night I only cycle along well lit roads. Tried an unlit lane a couple of months ago, and had to cycle slowly anyway as I didn't know the lane very well, and was concerned I might hit an obstacle or pothole. But the worst thing was the occasional oncoming car. Had to stop as the headlights were blinding and disorientating. I won't be trying that again in a hurry.
I prefer cycling at night - when else do cars reduce in number enough, for one to enjoy the road? Mind you, drivers are much worse during pub hours, and after they close... even blinder than usual - half awake and slow to react. This helps:


It's prevented many a collision with people and vehicles, also works on other animals. Gives you a loud retort to rude beeping *sshole drivers.
 
Last edited:
Sep 13, 2020
82
40
Very good recent article on this

Thanks for that really comprehensive link.

Germany’s StVZO bike light regulations dictate that flashing bike lights are not permitted on either the front or rear of a bike, with the regulations stating that flashing patterns can be distracting to other road users.
I did wonder that.

The study found the flashing light was far superior on the straight road, allowing detection of the rider from three times the distance of the steady light. This equated to detection 82m sooner, on average.
Logical.

The 2017 Clemson University study also examined mounting lights to the heels of a cyclist.
The study found that “when steady lights were mounted to the cyclist’s pedalling heels, participants [identified the cyclist] from a mean distance that was 1.7 times greater than when a flashing light was mounted to the seatpost”.
This figure increased to 5.5 times when compared to a steady light mounted to the seatpost.
They sound useful.

The lights cyclists use inevitably affect other road users, one particular concern being the impact flashing lights could have on people with epilepsy. However, according to Epilepsy Action, photosensitive epilepsy is rare.
Never thought about that at all - although it sounds as though the flash rate is too slow to have that effect. Even so.......

Choosing a rear light with a lower flash rate or with a less severe flash pattern (e.g., not on/off flash) should reduce dazzle for other road users and minimise the risk to those with photosensitive epilepsy.
Combining this with a steady rear light could then maximise the ability of other road users to detect your distance and speed – allowing you to be detected early, identified as a cyclist and approached safely.
A combination might be the best way forward.
 

trevor brooker

Esteemed Pedelecer
Feb 11, 2018
252
129
60
maidstone
You're right it's several orders of magnitude more dangerous than cycling in daylight. If I go out at night I only cycle along well lit roads. Tried an unlit lane a couple of months ago, and had to cycle slowly anyway as I didn't know the lane very well, and was concerned I might hit an obstacle or pothole. But the worst thing was the occasional oncoming car. Had to stop as the headlights were blinding and disorientating. I won't be trying that again in a hurry.
I find the opposite.
During the day the roads are busy & RTV can judge widths so will do close overtakes.
At night my combination of lights (steady centre & flashing at the width of the handlebars) & fewer cars leads to overtaking as if I were a car.
Today I took some items to the local tip (we have to prebook & provide a vehicle registration number - so I use my moped number from 1977) & found why I dislike day journeys - lots of impatient traffic & bright blinding low sun!
 
Sep 13, 2020
82
40
I find the opposite.
During the day the roads are busy & RTV can judge widths so will do close overtakes.
At night my combination of lights (steady centre & flashing at the width of the handlebars) & fewer cars leads to overtaking as if I were a car.
Today I took some items to the local tip (we have to prebook & provide a vehicle registration number - so I use my moped number from 1977) & found why I dislike day journeys - lots of impatient traffic & bright blinding low sun!
Obviously daytime cycling can also present challenges, depending on cloud cover, low Sun in Winter and increased traffic. But generally speaking I do prefer it to night time cycling. It's much easier to see surface hazards from a greater distance in daylight than in darkness, even with street lighting.

I wouldn't even contemplate. for example, night time cycling in icy conditions.
 

trevor brooker

Esteemed Pedelecer
Feb 11, 2018
252
129
60
maidstone
Obviously daytime cycling can also present challenges, depending on cloud cover, low Sun in Winter and increased traffic. But generally speaking I do prefer it to night time cycling. It's much easier to see surface hazards from a greater distance in daylight than in darkness, even with street lighting.

I wouldn't even contemplate. for example, night time cycling in icy conditions.
I agree about the icy conditions but what jumped to my attention was your comment about street lighting - I had to think what you meant - I mainly ride on country lanes with no lights apart from my cycle lights.
We get so used to our normal that we think it applies to everyone else as well.
 
Oct 20, 2021
203
65
@Nealth
Glad to hear that mate, though sorry for the poor bugger that did.
Nealh also broke his wrist (in a separate accident). Ironically I was injured by a Gaulish god of healing, which is most troubling and makes no sense. An extract from badger nadgers was used for ceremonial purposes or something.:




45254
 

guerney

Esteemed Pedelecer
Sep 7, 2021
3,680
1,372
I find the opposite.
During the day the roads are busy & RTV can judge widths so will do close overtakes.
At night my combination of lights (steady centre & flashing at the width of the handlebars) & fewer cars leads to overtaking as if I were a car.
Today I took some items to the local tip (we have to prebook & provide a vehicle registration number - so I use my moped number from 1977) & found why I dislike day journeys - lots of impatient traffic & bright blinding low sun!
They misjudge ebike speed with close overtakes - I've had more very close calls since converting. It keeps happening - frequently cars try to overtake during the day, but then screech to a halt in front of an approaching vehicle or road island when they can't do so in time, because they assume that I'm be travelling at about 10mph, when I'm ebiking at 15mph. Whenever that happens, I'm left wondering what effect being directly next to a collision would have on me and my bike, or how bad my injuries would be if the driver swerved left again in panic, and knocked me off the road. This also happens at night: one boy racer misjudged my speed a few weeks ago, and actually swerved to the other side of the road, around a road island he would have hit. On the bright side, my flashing light + rear continuous light + flashing LED sash + high vis clothing + flashing light on the handlebar flashing directly onto my high vis and reflective blouson + extra reflective tape on my helmet with jawguard + relective tape strips on my bike frame + hiviz rucksack cover on my rear rack battery + extra blinky cree torch near my rear wheel with lens painted red using a permanent marker pen, must have been seen....that time.
 
Last edited:

The Silverfox

Pedelecer
Oct 13, 2021
75
25
Cardiff, UK
Much like with cars and motorcycles, I think having lights on during the day is just as important as at night. They help draw attention to you and stop you blending into your surroundings.

I use one flashing and one steady on the rear at night. During daylight I use the flashing one.

On the front I use a bright flashing light during the day and a steady one in darkness.

On a 10 minute drive the other night I counted four cyclists at separate locations with no lights at all and three of them were wearing all dark clothing. I really don’t understand their mentality.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
3,680
1,372
On a 10 minute drive the other night I counted four cyclists at separate locations with no lights at all and three of them were wearing all dark clothing. I really don’t understand their mentality.
Death can't see them, if they're wearing dark clothing and cycling without lights?
 
Last edited:
  • :D
Reactions: trevor brooker

guerney

Esteemed Pedelecer
Sep 7, 2021
3,680
1,372
Much like with cars and motorcycles, I think having lights on during the day is just as important as at night. They help draw attention to you and stop you blending into your surroundings.

I use one flashing and one steady on the rear at night. During daylight I use the flashing one.

On the front I use a bright flashing light during the day and a steady one in darkness.

On a 10 minute drive the other night I counted four cyclists at separate locations with no lights at all and three of them were wearing all dark clothing. I really don’t understand their mentality.
The only bike lights I ever notice during the day are the megawatt headights on some motorbikes. Someone posted up an 6" or 8" motorbike headlight mod for his pedelec a couple of months ago - wired to his battery, which I might attempt.
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
2,004
1,382
67
West Wales
Steady state bright lights in low sun conditions can be counter productive.
During WW2, some tanks were fitted with bright headlights. They would be used as the vehicles came over a ridge line with bright sky behind. The effect was to break up the outline of the tank making it harder to spot/recognise, in the same manner as camouflage.
This is why I wear a one colour yellow jacket, to present a solid block to view, rather than any kind of broken up or patchy presentation.
I also use a combo of steady and flashing lights at night. My pedals have micro generators in them and 8 flashing orange leds. Very eye catching. Recently, however, the offside one's leds have failed. Halfords no longer seem to do them and I can't find any. Anyone know?
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
3,005
2,269
This also happens at night: one boy racer misjudged my speed a few weeks ago, and actually swerved to the other side of the road, around a road island he would have hit.
This has happened to me several times at the same spot; all daytime, some bike and some ebike. Slight uphill, probably not travelling at more than 8mph.

We don't ride any faster now we are on ebikes than before we changed, and quite a bit slower than we used to ride 25 years ago.
 

georgehenry

Esteemed Pedelecer
Nov 7, 2015
1,229
1,071
Surrey
I got cut up today leaving a roundabout by an impatient old couple behind me in of all things a Cherolet Matiz . I shouted my displeasure but they were oblivious. She was close to me at the start of the overtake choosing to make the overtake as we were both leaving the roundabout and then came over towards me before she was quite past me. Really quite a close call in one of the narrowest cars on the road where she could have either waited until we were both clear of the roundabout or even overtaken me with cars coming the other way if she had done so by driving close to the crown of the road which due to the narrowness of the car would have been fine. I am as sure as I can be that it was just bad driving rather than with any malice intent.
 
  • Agree
Reactions: trevor brooker
Oct 20, 2021
203
65
I prefer cycling at night - when else do cars reduce in number enough, for one to enjoy the road? Mind you, drivers are much worse during pub hours, and after they close... even blinder than usual - half awake and slow to react. This helps:


It's prevented many a collision with people and vehicles, also works on other animals. Gives you a loud retort to rude beeping *sshole drivers.

I agree, the Honit 140db is ace! The third idiot in this video could have ran me over and killed me... BMW started to overtake while coming out of a bend right at me, stopped his maneuver last possible moment screeching his tyres. Horn wouldn't have helped, my yellow hiviz jersey did. I was looking death in the face, and it was BMW shaped:


 
Last edited:
Sep 13, 2020
82
40
I agree, the Honit 140db is ace! The third idiot in this video could have ran me over and killed me... BMW started to overtake while coming out of a bend right at me, stopped his maneuver last possible moment screeching his tyres. Horn wouldn't have helped, my yellow hiviz jersey did. I was looking death in the face, and it was BMW shaped:


I must be honest - all three looked relatively innocuous to me. First one you could see the slightly open door from some considerable distance, and the guy obviously saw you as well.

Second one the car was only gently starting to pull out and then immediately stopped when he realised you were turning right.

Third one - sorry, but I didn't detect any actual attempt at overtaking, just two cars quite close to each other, and in line.
 

AndyBike

Esteemed Pedelecer
Nov 8, 2020
373
174
Flashing lights/steady lights and the law-
They really couldnt give a toss, they've more important things to be doing.

Having no light will have them giving you a warning, or even preventing you from cycling if the conditions are so poor it would be dangerous for you to continue.

But if its flashing, or if its steady, they wont bother you about it. Not even if theres no rear reflector, just as long as there is a light, the boys in blue are happy and will leave you alone.
 
Oct 20, 2021
203
65
I must be honest - all three looked relatively innocuous to me.
My camera's microphone is awful, so please do increase the volume of your viewing device, it's a low volume which my camera produces. It's also in a waterproof case. My helmet camera distorts the impression of distance. I would use the camera distortion removal feature, but then the view becomes very narrow. Hope I'm not presuming, but our two eyes see far wider and clearer, have far superior dynamic range, than any action camera. In the videos, driver's faces are not visible, but I could clearly see where driver's were looking - I've found that looking driver's in the eye is a good way to guage what they are actually looking at, and whether they have noticed me, sadly faces and eyes aren't visible in the video my camera produces, the human eye is far superior. It makes me question the usefulness of my helmet camera's "Flight recorder" function, should something horrible happen and I need evidence. I might experiment, setting to remove distortion automatically in-camera in future.

First one you could see the slightly open door from some considerable distance, and the guy obviously saw you as well.
If there was no distortion, perception of distances would be more accurate. I could clearly see their faces. The chap opening the door didn't see me at all, neither did his companion, and it was only after I beeped that he noticed, and started to close his door. I would have been forced to swerve further to the right if he hadn't, which risked possible collision with vehicles overtaking.

Second one the car was only gently starting to pull out and then immediately stopped when he realised you were turning right.
Did you hear his angry tyre squeal, as he pulled away afterwards? You might have to turn up the volume and use headphones to hear it, and engine noises. The young Caribbean driver looked angry. The driver and his friend looked like they were having a great conversation as they pulled up to the intersection, the driver didn't look in my direction at all until I beeped, too busy chatting to his mate, and even then he moved to cross right in front of me. I had right of way. If I was in a car, he would have waited for me to turn right, because I would have been blocked his way. There appears to be a blind spot or something: Drivers don't see bikes at about 30 to 45 degrees either side, after stopping to turn - they look at fully 90 degrees left or right, but miss seeing bikes situated (or have moved to) slightly further toward the middle, for some reason. I'm sure cars would be more visible in the same situation, as they are larger and occupy more of the driver's field of view. Plus drivers don't often see bikes anyway, because they mostly expect to see cars. I've frequently seen drivers screech to a stop, when they suddenly see a bike move out of that blind spot. A driver who did that the other night actually swore "F&king hell!" as he suddenly saw me and slammed on the brakes after accelerating at me, while turning onto the main road I was travelling along - he didn't even look to his right, which worried me, didn't slow down much and wasn't going to actually stop before turning into ther main road from the side road to my left. I had slowed down and was wondering whether to beep to alert him to my prescence, and I should have but didn't - I hate beeping, seems rude and should be unnecessary, especially in that situation, when he should have looked right at least once. He slammed on his brakes when I was directly in front of him, having moved out of that blind spot, which shouldn't be a blind spot, or wouldn't be a blind spot if I were driving a car. The video of that was too dark, or I would have included it. No helmet camera seems any good at night.

Third one - sorry, but I didn't detect any actual attempt at overtaking, just two cars quite close to each other, and in line.
That one was utterly terrifying. If you turn the volume up or use headphones, you can hear his tyres screech as hie rapidly alters trajectory (about 38s into the video). If he hadn't rapidly changed course, I'd have been toast. He actually ducked to avoid my horrified gaze as he passed, looked sheepish. I was a "Deer in headlights", and would have been squished or airborne.

I totally understand if my camera recordings don't accurately show what occurred, and that you don't see what I saw and heard. If I only saw these videos and wasn't there, I might be of the same opinion as you, possibly. At least my helmet camera picks up number plates, which may be of use in a hit and run situation.
 
Last edited:
Oct 20, 2021
203
65
Flashing lights/steady lights and the law-
They really couldnt give a toss, they've more important things to be doing.

Having no light will have them giving you a warning, or even preventing you from cycling if the conditions are so poor it would be dangerous for you to continue.

But if its flashing, or if its steady, they wont bother you about it. Not even if theres no rear reflector, just as long as there is a light, the boys in blue are happy and will leave you alone.

Drivers worry me far more than the boys in blue! I have a mind to add more lights! I might install this 20W motorbike headlight, so it's claimed to be, to my bike as soon as I can. I'll risk my broken but 8 week plated and healed wrist by dragging my bike up the stairs to inspect badger damage, to do so.


45262
 
Last edited: