Daytime Lights

[axolotl]

Anyone else use their lights during the day? My new bike came with a dynohub and bright flashing light on the front that runs continuously, whenever the bike is moving and for a minute or so after it stops. At first, I thought it was a bit overkill, but I'm beginning to realise that it makes a real difference. People see the flashing light and realise there's a bike coming.

It got me wondering whether some daytime accidents could be avoided - the type of accident where the gormless motorist says "sorry, I didn't see you" after pulling directly into your path.

At a time when the EU are saying all cars should have daytime running lights, and given that we're a lot more vulnerable than a car, maybe we should too?

 

[Deleted member 4366]

I like the idea of daytime lights. It certainly worked for motorbikes. The only problem is that you can't get something for nothing, so your pedalling not only has to power you, but also the lights. Spin the wheel with and without the lights on to see how much difference there is.

 

[axolotl]

Spin the wheel with and without the lights on to see how much difference there is.

I did wonder about this, so I tried it with the lamp physically disconnected. Freewheeling the bike on a stand, there's a slight difference in the time take for the wheel for come to rest. Whilst actually riding the bike, there's no discernible difference.

That said, I'm using a new Shimano dynohub, not one of the old-fashioned bottle-shaped dynamos that do create a noticable amount of drag.

 

[axolotl]

Of course, if you used battery-powered lights, the point is moot.

And I think there's a big safety benefit here.

 

[electric.mike]

Had a chap coming towards us the other day with a flashing light at the front,in daylight it still was very noticeable and i think it was just one of the cheapish battery operated units.

 

[Deleted member 4366]

I did wonder about this, so I tried it with the lamp physically disconnected. Freewheeling the bike on a stand, there's a slight difference in the time take for the wheel for come to rest. Whilst actually riding the bike, there's no discernible difference.

That said, I'm using a new Shimano dynohub, not one of the old-fashioned bottle-shaped dynamos that do create a noticable amount of drag.

Let's say you had a non electric bike with a dynamo-powered 3W headlight on all the time. Let's also say that the dynamo was 100% efficient, so no friction drag. The average non-sporting cyclist pedals along with a average power of between 50w and 100w, so that's about 5% of your power would go to keeping the light lit. It's more significant than you think.

Obviously, with an electric bike, you can turn up the motor a bit, so you don't have to pedal harder, you just use the battery faster. For a 300wh battery, you'd use 1% per hour, which is insignificant.

 

[axolotl]

Obviously, with an electric bike, you can turn up the motor a bit, so you don't have to pedal harder, you just use the battery faster. For a 300wh battery, you'd use 1% per hour, which is insignificant.

Exactly. As I said, you don't even notice it.

On the other hand, I think the improvement in safety IS quite noticeable.

 

[neptune]

If one feels that the dynamo drag is significant, another approach would be to run your headlamp from separate rechargeable batteries.

 

[jackhandy]

Had a chap coming towards us the other day with a flashing light at the front,in daylight it still was very noticeable and i think it was just one of the cheapish battery operated units.

Wasn't there some discussion, a while back, about bright blue/white flashing leds being mistaken for emergency services' blues?
I get some funny looks when I have one of my Cree T6 front lights flashing in poor visibility.

 

[electric.mike]

Wasn't there some discussion, a while back, about bright blue/white flashing leds being mistaken for emergency services' blues?
I get some funny looks when I have one of my Cree T6 front lights flashing in poor visibility.

Doesn't matter around here nobody notices emergency vehicles anyway

 

[Gubbins]

Whilst driving this week I spotted a cyclist with a not too bright flashing front light.... The fact that I noticed it means it was doing just what the rider intended.

 

[01423frankieboy]

Volvo cars were the first to introduce constant lights. The statistics they have on the safety benefits are amazing; 10 or 15% less accidents in Daylight in Sweden since they were introduced.

 

[axolotl]

Wasn't there some discussion, a while back, about bright blue/white flashing leds being mistaken for emergency services' blues?
I get some funny looks when I have one of my Cree T6 front lights flashing in poor visibility.

Really, if you're struggling to tell the difference between a bicycle and and emergency vehicle, you really need to go and see your optician, ASAP.

Motorists driving without their specs on is a whole other can of worms though. With our ageing population in the UK, I reckon it'll be the next big thing, following on from mobile phone users and drink driving.

For whatever reason, it seems most motorists are very quick to say "sorry didn't see you mate" in the event of a collision. And based on the experience of the last few weeks, I'm convinced that having a bright, flashing light makes you a lot more noticeable, and therefore safer.

 

[Cyclezee]

I'm in favour of daytime lights on all vehicles that use the road, but then I drive a Volvo

It is mandatory in several European countries and many modern cars have 'all ways on' LED's.

I always have lights on when cycling, the power consumption is tiny so why not be more visible.

 

[Cyclezee]

I would just like to add that whatever vehicle you ride or drive why just have your lights on all the time, it costs nothing except the occasional light bulb and if it prevents a single death or even a minor injury it has to be worth it.

Just a couple of things, if you are driving a motor vehicle please make sure that you are using dipped headlights, not just sidelights and please only use front or rear fog lights when it is actually foggy or visibility is poor.

 

[electric.mike]

My car has DLR lights but the speedo is too recessed and my need for reading glasses means i have my side lights on all the time any way just to be able to read the speedo.

 

[JohnCade]

Yes the number of vehicles who just use sidelights in poor visibility is astonishing. Even in heavy rain it's hard to pick them out clearly, and in fog you will always see the vehicle before you see the sidelights. Drivers of dark or gray cars on gray days without lights, or just sidelights, are asking for a head on by some overtaking twat coming the other way who just wasn't looking hard enough.

I use headlights all the time unless the sun is actually shining when I usually don't. I use a flashing light on the bike too, and when I rode motorbikes I always had the lights on even in bright sunshine.

 

[D C]

I use headlights all the time unless the sun is actually shining when I usually don't. I use a flashing light on the bike too

Me too, even front flasher when off road with the bike if I am on a busy track, (not often in these parts)
On one of my cars you can't even turn the lights off if the ignition is on, maybe it's time to make "lights on when moving" a legal requirement on all vehicles so you can then see the one car in a long line running without lights.
Dave.

 

[peerjay56]

... please only use front ... fog lights when it is actually foggy or visibility is poor.

This one has always puzzled me. How can front fog lights 'dazzle' oncoming drivers? (I know you didn't say that John, but it is the usual reason given when insisting front fog lights should only be used in poor visibility)
They are set to light the nearside kerb and road not far in front of the car. In darkness on some of the appallingly maintained roads around here, they are actually helpful for picking out potholes and other hazards. I am genuinely mystified as to how they constitute a hazard to oncoming drivers.
Tin hat on, climbing into bunker now.

 

[axolotl]

This one has always puzzled me. How can front fog lights 'dazzle' oncoming drivers? (I know you didn't say that John, but it is the usual reason given when insisting front fog lights should only be used in poor visibility)

I'd think the main reason you should keep your fog lights off unless visibility is severely compromised is because it's the law.

Unfortunately some motorists in these parts seem to think that sidelights + front fog lights is a cool alternative to actual headlights, at night. Fortunately they do occasionally get pulled over and ticketed for it.