Don’t be a clown, tilt them down! – a bike light primer

Dont be a clown, tilt your lights down

Think about this: someone in charge of a thousand plus kilograms of metal is coming towards you at 50kph or faster. They will pass within a metre or two of you. The only thing between you and them is a stripe of paint on the road. Your light is shining in their eyes. It’s blinding them. Does that sound like a clever idea?

There have been a few threads on the Australian Cycling Forums recently about using bike lights in an anti-social manner. One thread was started by a motorist who was blinded by, and almost hit, a cyclist; the other thread was started by a fellow cyclist who was blinded on a bike path. These topics pop up regularly, so it makes sense to create a bike light primer. There is a lot to say about lights, and I suggest you do some research, but here are some things to keep in mind and consider when buying or using bike lights.


Do I Need Lights?
Yes. If you’re travelling in the dark or in low light conditions, you’re legally obliged to have them. You need a white light at the front and a red light at the back. They need to be visible from 200m away. That’s what the law says and you should consider that the absolute minimum requirement. A legal lighting setup however is not necessarily a useful lighting setup.

Bicycle Lights Road Cycling Echelon


Day and Night?
You’ll notice that many motorbikes have their headlights switched on all of the time, day and night. Sometimes it’s the rider who does this, but often it’s a built in feature of the bike. Research suggests that it makes the motorbike more visible on the road and reduces accidents.

Following this theme, there are many cyclists who ride with flashing front and rear lights at all times. I haven’t seen any research on this for bicycles, but it certainly doesn’t hurt. Try it out and see if it makes a difference.


See or Be Seen?
Regardless of technological differences, all lights fall into one of two categories: lights to see with and lights that allow you to be seen.

Lights to see with are high powered lights with appropriate beam profiles that allow you to see your surroundings in the dark and while riding at speed. If you’re riding in the bush or somewhere with no street lights, you will need much higher powered lights. Experienced night riding mountain bikers will understand the need for these.

MyTinySun Bike Lights Night Mountainbike

If you’re riding in suburbia where there are street lights and lots of other light pollution, you don’t need super high powered lights. No, you really don’t. If you are a road rider and you want to run with high powered mountain bike lights, use the light’s lower output settings. You don’t need really high powered lights in the city. No.

Knog blinder lumens white cycling safety light

Lights to be seen with are lower powered lights and are designed to make you visible to others, rather than allow you to see with in the dark. You see these types of bike lights in supermarkets and department stores. They comply with the law, but not with reality. They do make excellent secondary lights and you should have one or two as back up. You shouldn’t rely solely on these to make your riding safe at night.

Rear lights are obviously only “be seen” lights. Some rear lights can be seen from the legally prescribed distance, but better rear lights can be SEEN from further away and from lots of different angles. Some rear lights can do even more.

Fly6 Taillight Flashing Camera

Fixed or Flashing?
Both. Most lights have both modes and if you’re riding with your lights on during the day, flashing is a great mode to use. Flashing mode not only gives you longer battery life (since you’re not constantly draining the battery), it also makes your light more visible; flashing lights appear brighter. (It’s an effect of Bloch’s Law if you’re interested in Googling it). Flashing lights are not good to see by, however. Using a flashing light for navigation purposes is dangerous. For night time riding, your front light(s) should be fixed beam.

Supernova lumins cycling

Rear lights are often used in flash mode regardless of the light conditions. I’ve read that having a fixed and a flashing light on the rear helps with (a) being noticed, and (b) helping depth perception of other road/trail users who are looking at your lights. The excellent thing about rear lights is that they can use very noticable flashing patterns and/or multiple synchronised lights, since you’re not using them to see with. They are the ultimate be seen lights.

Knog Blinder R Road Rear red bike light


More power?
It’s all about the lumens. Power is a measure of electrical power used by the light (i.e. voltage x current), while lumens is a measure of how much visible light is emitted. It’s actually an EU requirement that lights are labelled with lumens, though other measures can be used as well.

Echelon Sports Gamma Ray ES501 High Beam

More lumens doesn’t mean better, since a single number doesn’t tell you important things like light beam profile, spread, spill, or even colour. You can have lights that have very wide and uniform illumination, you can have lights that have a very bright centre spot, and you can have lights that have a yellow or bluish tinge.

Supernova german australia bike light

So how do you know if a light is fit for the purpose that you want? You really need to read reviews from experienced users, such as the ones featured here on BNA. Reading reviews or receiving recommendations from people who have used a particular light will save you a lot of money and frustration.


Front Light Mount Points

This is the most common location for front lights.

+ It’s a convenient location for turning lights on and off, and the lights can usually be easily removed and reattached to the mounts.
+ Good for most situations.
The light is mounted high; for larger bikes this could be close to the eye level of a motorist or pedestrian. Typically the only adjustment up and down is by rotating the light around the handlebar.
Bumping along the road can cause the light to angle up to motorist/pedestrian eye level.

This is a very common location for smaller, secondary “see me” lights. Not as good for primary lights.

+ The light points wherever you’re looking – so you can see in all the directions you look.
The light points wherever you’re looking – so it may not be seen by people looking at you.

This was a typical location for mounting lights on older bikes and there were often dedicated attachment points on forks for lights.

+ Low to the ground, so as not to dazzle. Illuminates the surface you’re about to ride over.
Hard to adjust while riding.
Many bikes don’t have suitable mounting points.
Many lights don’t have suitable mounts for forks or mudguards.


Rear Light Mount Points

Seat post
This is the most common location for rear lights.

+ Usually provides the best location for maximum visibility near the center of mass of the rider.
+ Good for most situations.
Can be obscured by seat bags.

The rear of the helmet is a very common location for smaller, secondary rear lights.

+ Good high mounting point for excellent visibility (in theory).
The light moves with your head and so may not be seen by people looking at you.

If you’ve got extra furniture at the back of your bike, light that sucker up.

+ Rear most point of the bike for maximum visibility.
Hard to adjust while riding.
Many bikes or their attachments don’t have these mounting points.
Many lights don’t have suitable mounts.

Ready, Aim, Fire
As I mentioned in my introduction, if you deliberately or accidentally shine your lights into someone’s eyes, you can temporarily blind them. You know what I’m talking about. The light receptors in your eyes become saturated and, even if the source of the light is gone, you can still be left with an after image that can blind you for several seconds. Several seconds while travelling at high speeds can be fatal.

MTB Night Riding Magicshine

Don’t be a clown, tilt them down. Aim your lights at the parts of the road or trail that you need to see and be conscious of other road/trail users. If you notice them reacting negatively to your lights, adjust them, either by tilting them down or turning them down to a softer setting. If that makes it hard to see your surroundings while you’re riding fast, simply slow down a bit. Riding is fun. Do what it takes to keep riding.

There is certainly a lot more that can be added to this primer, so if you have any rules or advice every rider should know, let me know in the comments below.

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About The Author

rides whenever and wherever he can; in good weather and bad, in sickness and in health...and mostly off the back of the peloton.

16 responses to “Don’t be a clown, tilt them down! – a bike light primer”

  1. matt king says:

    There is a fundamental issue with just “tilting them down”, which will be required for front lights with beam patterns that are symmetrical (ie the same pattern up and down around the centre hot spot of the beam).

    In order to prevent excessive light spilling into oncomers’ eyes, the light (assuming it has adequate beam width to be useful) typically needs to be angled down a long way. This creates a very bright spot on the road only a couple of metres in front of you. As the rider, your eyes then adapt to this brightest spot, and your ability to see objects further away decreases (even more so than if you just had a less-bright light aimed horizontally). You get the same problem that you’re trying to avoid the oncomer having.

    The only real solution is to buy (or make) a light with a proper cut off beam pattern, such that it throws bright light a long way, and is progressively dimmer on the ground closer to you, but does not spill excessive light above the horizontal plane. Cars have had this for years with their low-beam pattern, which is rarely dazzling, even with very high outputs, unless aimed incorrectly.

    Bike lights of this sort are also readily and relatively cheaply available, mostly from Europe where the German StVZO standards (for example) are enforced.

  2. Nathan Duhig says:

    I used to subscribe to the ‘more is better’ philosophy, using symmetrical MTB lights for commuting. It took another cyclist who I respect greatly to point out how unfriendly my lights were, particularly when flashing. Given the current arms race in lighting, I am certain that death and/or serious injury will occur as a result of well meaning, yet ignorant, cyclists using a symmetrical MTB lights on roads and bike paths, in either flashing or high powered modes.
    The European standards described in the post above represent the future for safe and sensible lighting. BTW, non-flashing rear lights are much safer as they are less distracting for following riders and drivers, and do allow for much better distance estimation.

  3. Matt King, yes – this really needs to come from the manufacturers and building lights that mount intuitively horizontal however with the light beam adjusted to avoid dazzling.

    There is usually an optimum angle but it depends on your speed and light power and while tilting the lights may help, as you suggest, there may still be too much light spill.

    Nathan, the advantage of flashing rear lights is capturing attention and getting recognition. I prefer lights that combine both flashing and steady.

  4. Chris Watt says:

    I have 2 lights on my bike one is on going to and from home even in daylight and is 1000 lumen on low setting.

    This is adequate for the ride home till I am probably 5 k’s from home I then have to crank it up a bit due to the lack of street lights as I live in a semi rural area.

    I’m not sure if it’s me but I do notice these light nazi’s with their lights maxed out and if your like me wearing glasses at night it doesn’t help when they are coming toward you.

    I agree the lights should be dipped down in suburban areas, but I always feel a little safer knowing if my lights are on then I can be seen.

    • Corsair says:

      1000 lumens? You’re foolish if you think that doesn’t adversely affect anything that is oncoming. I ride a completely unlit cycle path at night and the 120 lumens I throw (just in front of me and tilted down) is more than enough to see properly. I think you’ve been caught up in the brighter is better brigade and I suggest you seriously review your set up before you create an accident…

  5. For clarification, Chris Watt said that the 1000 lumen light was usually on a low setting, and a guess is that this would be 20 – 30%.

    While there may be a limit to the power – it depends upon the surrounding light conditions as to how much power is required to let you see ‘a bit’ or ‘adequatly’ or ‘well’. It also depends on speed and how far ahead you want or need to see ahead to ride confidently.

    But about ‘being seen’ a dazzling light, whether it is 200 watts or 1000 watts will still dazzle and create the effect that oncoming traffic find it harder to see. The brighter, the worse. But dazzling doesn’t make it easier for others to see you so breaks the myth about brighter is better. Oncoming traffic needs to see enough light.

    I will run a few tests on light angles to see if I can provide some hints on this.

  6. Along with other commenters, I would strongly advise people who cycle at night to purchase a German style light, that has optics similar to car headlights. They throw lots of light on the ground so you can see where you’re going, and enough forward so people can see you without being dazzled.

  7. Ray Jones says:

    Having been a proud owner of StVZO compliant (Lumotec Cyo) LED lights for many years now I concur that bicycle lighting should be required to conform to shaped beam requirements.
    The beam is “hottest” at the very top and blends downwards very nicely. Shine it at a wall and you’d reckon they’d be useless, put one on your handlebars and aim it correctly and prepare to be amazed what you get from a lowly 3W LED that correctly places light where it’s most needed.

    I still recall the day I was about to abuse an oncoming cyclist for his dual (I presume Ayup) high power beams blinding everybody he approached. I quenched my enthusiasm when I realised in the last few seconds he was a bicycle cop and I had no bell :-/

  8. Link to Reddit Thread – Remember when riding at night, don’t be a clown, tilt them down:

  9. David says:

    This has been answered by Philips with Safe Ride but it seems they’re alone at the tea party.

    I have a new one and it works well as main light, with Cygolite Expilion 350 available as flasher, or MTB height when alone in total blackout areas. Bonus redundancy of two lights. Like regular and high beam on cars.

  10. Roger Webber says:

    I run dynamo lights now, with a German Edelux headlight and a non-flashing rear. The front has a shaped bean with a sharp cutoff so I can see, but I don’t blind oncoming riders or drivers. The Edelux is brilliant (no pun intended) for seeing and being seen. I also run a secondary battery “be seen” light front and rear, as I believe that having two lights with a little separation between them provides a much greater ability for drivers to judge distance to where you are, rather than having a single “point” of light.

  11. WestcoastPete says:

    I don’t often commute during regular commuting times, but when I do I’m amazed and dazzled by the amount of flashing lights. It really messes with my zen man, putting me off kilter. Yeah, super bright lights are a big problem and I’m really, really glad to see this article about it; the message needs to spread. But I reckon that if everyone had good quality fixed beam lights, we’d all be a munch happier bunch, and we’d all be seen and be able to see just as well.

  12. […] article on BNA about how having super bright lights is shit. They still promote flashies though… Reply With […]

  13. boss says:

    I would just like to put forward that different cyclists have different needs. Riding down a hill at 60-70kmph in dark and damp conditions on unlit roads… I’ll take all the lumens I can get.

  14. trailgumby says:

    Just a note on using flashing lights on the trail: most event organisers ask riders at 24 hour events to have their rear red lights on constant beam and *not* flashing. Having had a member ride with a flashing rear light on a night-time group ride, I understand why and had to ask him to put it on constant mode. Flashing made it hard to see, despite having a massive 2700 lumens + head mounted lights.

    As to using mountain bike lights on the roads, I agree with the sentiments above. I have mine pointed down and rarely use full beam.

    But, as boss has indicated above, there are situations where pointing them up and using full power is necessary for risk management.

    Having gone down hard in the dark at around 50km/hr on a road covered in oil thanks to a broken government bus, I am wary and like to see where I am going in situations where riding at less than traffic speed is risky.

  15. Sar says:

    Thank goodness for this post. So it’s not just me!!


    When it’s dark and the only source of light is the glaring light from an oncoming cyclist, it doesn’t help that you can’t see ANYTHING behind him!! I didn’t see the pedestrian that was right in front of me because of it!!

    Up until that point I was just annoyed by blinding lights and thought I should just keep it to myself…but after that moment…I realized it’s a serious safety issue. Is there anything that can be done to regulate this kind of thing in Australia?!