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Re: Front Lights in Daylight

Posted: 28 Aug 2020, 3:22pm
by thirdcrank
tim-b wrote: where does the 240/minute come from? ...


The explanation is here, in this extract from the govt guide to bike lights

Purely flashing lights are not required to conform to BS61023, but the flash rate must be between 60 and 240 equal flashes per minute (1 to 4 per second) and the luminous intensity must be at least 4 candela. (This should be advised by the manufacturer).


https://www.gov.uk/government/publicati ... s-lighting

AIUI, the point is that the lighting regs require all vehicle lights to be steady lights and flashing lights on pedal cycles are an exception to that rule ie they must comply with this flash rate. In my earlier post I should also have mentioned that the rate has to be "equal."

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 3:36pm
by JohnW
OldLimey wrote:...........I don't trust any driver to pay attention to cyclists..........


There speaks a man of experience - not prejudice, but hard experience.

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 3:39pm
by JohnW
Sweep wrote:.........in my experience cyclists with strong rear flashers in daylight are the most likely to give this cyclist a silent near pass........


That's interesting - are you sure? - have you had bad experiences?

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 3:57pm
by JohnW
thirdcrank wrote:
tim-b wrote: where does the 240/minute come from? ...


The explanation is here, in this extract from the govt guide to bike lights

Purely flashing lights are not required to conform to BS61023, but the flash rate must be between 60 and 240 equal flashes per minute (1 to 4 per second) and the luminous intensity must be at least 4 candela. (This should be advised by the manufacturer).


https://www.gov.uk/government/publicati ... s-lighting

AIUI, the point is that the lighting regs require all vehicle lights to be steady lights and flashing lights on pedal cycles are an exception to that rule ie they must comply with this flash rate. In my earlier post I should also have mentioned that the rate has to be "equal."


tc - a problem that we all have is that manufacturers quote the power of their lights.in different units. Some manufacturers quote 'Lumens', one even quotes 'watts', and do some quote 'Candela'? We need a British Standard, which we can all understand and with which all distributers must comply by law. There is a BS for cycle lights, but the two BS compliant cycle front lights that I have (state of the art when I bought them) are about as bright as a sickly glow-worm.

In my experiences, a very strong flashing light is most effective in traffic, on well-lit roads in the dark, or in daylight, for identifying that there is a cyclist.

What a driver does is up to them - and we all know motorists, don't we?

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 4:19pm
by tim-b
Hi
@TC, Thanks for that
Regards
tim-b

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 4:40pm
by mjr
fausto99 wrote:One thing that should be stopped immediately IMO is cyclists with black bikes dressed all in black. It's a nightmare when I'm in my car. Rant over.

Sorry but no, that sounds like it's time to fix your car's headlights or hand your licence back IMO, before you hit an animal or unlit tree fallen on a dark road.

What I wear is pretty much irrelevant to visibility because my bikes have good German-spec lights, wheel and pedal reflectors and reflective wheel bands and some of them have the rear quarter of the back mudguard painted white. Any driver looking at my bike doesn't need to see the rider. Even so, positioning makes far more difference than the bike, but any of you riding around with substandard lights, black mudguards and no pedal or wheel reflectors don't really have a leg to stand on to lecture about visibility, do you? ;)

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 4:42pm
by mjr
JohnW wrote:We need a British Standard, which we can all understand and with which all distributers must comply by law. There is a BS for cycle lights, but the two BS compliant cycle front lights that I have (state of the art when I bought them) are about as bright as a sickly glow-worm.

So there is a standard and compliance with it is not a guarantee of being much use, but you still want to force sellers to comply with a standard? That sounds like red tape, a licence for BSI to rake in more money for its useless standards and overall a waste of valuable effort!

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 4:54pm
by hamster



It can indeed process an image in 13ms. But you cannot perceive flickering over 75Hz (the reciprocal of 13ms). A good example is with modern LED brake lights - they look steady until you flick your eye across them - in which case you perceive a series of dots. So indeed you can see a single 13ms flash, but cannot separate a series of them.

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 5:20pm
by LittleGreyCat
mjr wrote:
fausto99 wrote:One thing that should be stopped immediately IMO is cyclists with black bikes dressed all in black. It's a nightmare when I'm in my car. Rant over.

Sorry but no, that sounds like it's time to fix your car's headlights or hand your licence back IMO, before you hit an animal or unlit tree fallen on a dark road.

<snip>


I don't think driving at night was mentioned, so the Ad Hominem is not really called for.

I witnessed this today, in a sudden downpour, in daylight.
Two riders dressed in black (T-shirts and shorts) on black bikes, apart from getting suddenly wet, more or less disappeared from view due to the suddenly worsening visibility.
Brighter clothing and/or some lights would have made them more visible - certainly to me, and I am bike aware when driving.

As an aside, the most perfectly stealthed cyclist I have ever seen whizzed past me late at night on the pavement after the street lighting had been turned off for the night.
Black bike, black clothing and in this case black skin. No lights, obviously.
I'm not sure that white skin would have made much difference, but if you want to be invisible on a dark night that is a pretty effective way to do it. :lol:

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 6:08pm
by fausto99
LittleGreyCat wrote:
mjr wrote:
fausto99 wrote:One thing that should be stopped immediately IMO is cyclists with black bikes dressed all in black. It's a nightmare when I'm in my car. Rant over.

Sorry but no, that sounds like it's time to fix your car's headlights or hand your licence back IMO, before you hit an animal or unlit tree fallen on a dark road.

<snip>


I don't think driving at night was mentioned, so the Ad Hominem is not really called for.

I witnessed this today, in a sudden downpour, in daylight.
Two riders dressed in black (T-shirts and shorts) on black bikes, apart from getting suddenly wet, more or less disappeared from view due to the suddenly worsening visibility.
Brighter clothing and/or some lights would have made them more visible - certainly to me, and I am bike aware when driving.

As an aside, the most perfectly stealthed cyclist I have ever seen whizzed past me late at night on the pavement after the street lighting had been turned off for the night.
Black bike, black clothing and in this case black skin. No lights, obviously.
I'm not sure that white skin would have made much difference, but if you want to be invisible on a dark night that is a pretty effective way to do it. :lol:

Hear, hear.

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 6:41pm
by Sweep
JohnW wrote:
Sweep wrote:.........in my experience cyclists with strong rear flashers in daylight are the most likely to give this cyclist a silent near pass........


That's interesting - are you sure? - have you had bad experiences?

:)
a bad day in the north downs a few weeks ago - passed by a group of folks who in broad broad daylight went past with rear red flashers.
two or three very close, no bell or anything.
I also see a few plonker cyclists in london with daylight power flashers.
i stress i am only talking about a subset but i fear that SOME of them have a me-me victim/superiority complex - ever quick to complain about drivers dissing them as cyclists, but care not much for other road-users.
and don't get me on the rear red eyeball-frying flashers mounted on a helmet :(

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 6:52pm
by simonhill
Strobe lights may be legal, but shouldn't the rider warn you that 'this bike contains flashing lights' like they do all the time on the TV.

Seriously though, could someone who is susceptible to flashing lights be harmed by these lights? They certainly make my eyes hurt.

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 6:58pm
by mjr
simonhill wrote:Strobe lights may be legal,

They're not. Flashing yes, strobe no.

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 7:04pm
by mjr
LittleGreyCat wrote:
mjr wrote:
fausto99 wrote:One thing that should be stopped immediately IMO is cyclists with black bikes dressed all in black. It's a nightmare when I'm in my car. Rant over.

Sorry but no, that sounds like it's time to fix your car's headlights or hand your licence back IMO, before you hit an animal or unlit tree fallen on a dark road.

<snip>


I don't think driving at night was mentioned, so the Ad Hominem is not really called for.

Nor did I mention night. And it's difficult not to comment on a person who outs themselves as unable to see some dark objects while driving.

I witnessed this today, in a sudden downpour, in daylight.
Two riders dressed in black (T-shirts and shorts) on black bikes, apart from getting suddenly wet, more or less disappeared from view due to the suddenly worsening visibility.
Brighter clothing and/or some lights would have made them more visible - certainly to me, and I am bike aware when driving.

OK, instead, this time I'll agree completely and say it's the responsibility of all others to adjust their clothing and vehicles to enable motorists(!)

Re: Front Lights in Daylight

Posted: 28 Aug 2020, 7:05pm
by simonhill
Deleted. Content moved to include a quote.