John-Paul Verkamp:Flickr

Cycling without lights. Cycling with them. Both can be a bit dodgy.

I’m not going to have to convince too many people that cycling without lights at night on the streets – or anywhere, really, is a bit of a daft thing to do. It just is. Are people really that stupid? I once saw a guy riding at night with no lights, dressed all in black, and wearing sunglasses to top it all off. So I guess the answer is, sometimes. When I say I saw him, I mean that I saw him when I was pulling up to a red light and he was crossing my path. He was pretty much invisible. The fine you have coming to you is probably not enough.

Daytime? I’ll admit that I rarely use lights, even though I know it increases my chances of being noticed by others. I don’t know, I think it’s just that I prefer uncluttered handlebars, and I’m stupid enough and stubborn enough to think that people really have no reason not to see me in broad daylight – but then we all know that’s not the case if you’re not looking where you’re going in the first place. A bright flashing light does grab a bit more attention.

Ok, so what about riding at night with a light? Is that ever a bad thing?

It can be.

More is not always better

Now, it wasn’t long ago that high-beams on cars were 1200 lumens. The current HID and LED low-beams on cars have been annoying drivers in their rear-view mirrors and head on for years already, never mind the high-beams.

Measuring light output can be a pretty confusing thing. Many different units of measurement are thrown around by the average person, and they change depending on the context. For example, you’ve got watts, lux, and lumens, and how they appear to your eye (intensity, glare, etc) can depend on how the optics are arranged. From experience, we probably all know that looking at two lights that are rated at the same power can yield very different results. If interested, this is a really simple summary of how some of the measurements compare.

Without getting into specific numbers, it’s fairly obvious that bike lights are getting pretty bright these days. 3000 lumens and more isn’t unheard of. The higher powered units really are just intended for off-road use, but often they find their way onto the streets for the nightly commute. This is where things start getting messy.

A good quality 250 lumen light is actually pretty bright. I wouldn’t depend on it for trail rides at night, but put it on flashing mode in traffic and you’ll be quite noticeable. If you want to see where you are travelling then more power is good, but there are other things to consider.

In vehicles, lights have more of a spread, so a light producing 2000 lumens reaches your eye at a lower intensity. I have no hard data to back this up, but high-powered bike lights do appear to be more intense to the eye than the average car headlight, which is likely because there is a relatively compact beam that the light is crammed into. Higher powered bike lights that have a nice, even, wide beam, may not appear to be as bright as a lower of similarly powered light with a narrow beam in the old point-them-at-a-wall-in-the-shop test, but the broad, even beam will be easier to see with. Cars with lights in excess of 2000 lumens, in Australia, have to ensure that they are leveled automatically so as not to dazzle other road users. Many people are using 1000+ lumen lights in traffic in a flashing mode, and most bike lights don’t have any anti-glare features (some do), nor are they required to, specifically, but even where there is no law pertaining to this, it makes sense to be reasonable when choosing the intensity of light to use while in traffic. Of course, you can easily point your light down, but that often doesn’t give you the illumination you want or need so as to give you enough time to react to an obstacle in the road.

I don’t know how many times I have seen other cyclists bearing down on me with really high-power lights flashing away. During the day this really isn’t an issue, as realistically, a lights brightness is in contrast to other light, so go as bright as you like. When the sun goes down, super bright bike lights make sense in terms of the cyclist being able to see where they are going, but it is quite difficult to see anything around the cyclist from a drivers perspective, and as such, you don’t really have a good gauge on their position. You would definitely know that they are there, but you wouldn’t know exactly what their position is relative to you. Add a dirty windscreen (inside and/or out) and/or rain to this and you’ve really got a problem. Put it on a flashing mode and it’s quite a problem indeed. You would get pretty upset and disoriented is a car behind or oncoming you was rapidly flashing it’s HID high-beams. Aside from the distraction and possible disorienting effect, it is more difficult to judge the distance and position of a flashing light than it is a steady light, so bear that in mind, or ride with one of each. I’m not sure why this situation is any different for cyclists. Actually, I do. It has everything to do with our vulnerability. We really, really want to be noticed by the surrounding traffic. And we really need to be. My point is that past a certain point, your light could actually be contributing to a dangerous situation.

Ride with a light. Ride with a few. By all means, get a bright one, but use it responsibly. If those around you can’t put your position on the road into context because all they can see is a white (or red, but they aren’t as bright) halo, then they can’t really see you in a useful way. Save the bright setting for night riding on trails, back roads, daytime, and when riding into the setting sun. Dip your headlights when pulled up behind a car at a red light. Keep yourself safe, but take a step back and think about the bigger picture.