How not to use bike lights

Cycling in the dark can be perfectly safe, as long as you ensure that you make it easy for other road users to see you.

The Highway code states that all cyclists must have a white front, and red rear light fitted to their bike before dawn and after dusk. It also states that you should have reflectors on your pedals, but since no clipless pedals actually incorporate this into their design, this one is never (to our knowledge) enforced.

If you are riding on lit roads, you don’t need a super high lumen light – ‘be seen’ lights are often 50 lumens on the front, and around 10 lumens on the rear – though this will of course vary either way.  If you want to take to country lanes and trails you might be looking for 700 lumens+.

Regardless which style of light you go for, you need to use it properly – here are some mistakes which are easy to make, but can cancel out even the brightest of beams:

1) Having a light, and covering it with your coat

This happens far too often – riders with all the best intentions fit a light to their bike, and then wear a long coat that completely covers it. This won’t help you at all, and could mean you completely eclipse your rear light.

2) Letting the light run out of battery

You can pick up lights with single use batteries for around £10 to £20 – but a lot of people these days opt for rechargeable battery lights, and most brands are making these with USB cable recharging systems. This means it’s really easy not to run the battery right down by accident – you just need to plug it in from time to time. However, it’s very easy to forget, the result being a sudden black out on the way home.

To avoid this, leave yourself a note on your locker/desk/other to remember to recharge, or set an alarm on your phone if you need to.

3) Not having a back-up

All the best intentions in the world, and the best equipment, cannot guarantee total reliabiliy. Of course, having quality lights and keeping them topped up does help keep you safe, but it is a good idea to have a back up – just in case.

Having a spare pair of lights in your bag – just a cheap sub £20 ‘get you home’ set such as the Storbe set from Knog – can get you our of a sticky situation should it arise, and set your mind at rest if it never does.


4) Not using lights in poor visibility conditions other than darkness

We all know that we need lights in the dark – but what about fog, heavy rain, and the early mornings and evening – when the sun is setting but still hanging around in the sky?

At these times, drivers visibility is still reduced, and turning your lights on for these occasions can make you stand out more.

Lights aren't only for when it's dark

5) Leaving bike lights attached when you lock your bike

Unfortunately, there are thieves out there that don’t care about your safety riding home. Most bike lights clip onto a mount, or attach via an elastic or rubber band – and they’re made to be easy to remove, so that you can take them on and off. Make sure you do this, as it isn’t uncommon for these to be stolen if left unattended.

Those are our ‘things not to do’ – have you got any to add, to help prevent our followers learning from experience?

Join 10,221 fellow cyclists who are subscribed to the London Cyclist newsletter

Sign up for our free newsletter to get...

  • Advice on the best cycling gear
  • A Friday roundup of all the latest London cycling news
  • Exclusive content not available on the blog

Subscribe today, and get exclusive access forever! (It's free)

*No spam, ever!

As seen on The Guardian, BBC and The Independent.

58 Responses to How not to use bike lights

  1. Peter 26/11/2014 at 1:09 pm #

    Almost as bad as letting your batteries run out, is letting them run down so much as to equate to the same thing. Just because you can see a bit of light when you turn it on at the start of your journey, with your face just inches away, does not mean they are going to be any use whatsoever whilst on the road. I see lots of cyclists like this – just press the button and cycle off without any consideration as to whether their lights are in a fit enough state to deserve the name.

  2. E 26/11/2014 at 1:37 pm #

    And don’t point high lumen lights into other drivers / cyclists faces.

  3. remerson 26/11/2014 at 1:42 pm #

    – Understand the difference between lights that are for illuminating the road surface and lights that are for making yourself visible to other road users.

    – Don’t position overly bright lights at such an angle that they dazzle other road users. You got the latest nuclear-powered LED thing from the shop? Well done you. Now *point it at the ground*.

    – You don’t need extremely bright lights in lit urban areas. Use medium-intensity flashing lights to be seen by. Streetlights will light the road surface, your lights are mostly there to get you seen.

    • CJ Bill 26/11/2014 at 2:19 pm #

      Indeed remerson, I do find people who have their lights at the right level to shine into your eyes whilst on canal tow paths to be not only inconsiderate but also dangerious. Blinding people coming the other way, even temporarily, is a sure fire way to end up in a head on collision or put someone in the cut

    • Kie 28/11/2014 at 11:57 am #

      “You don’t need extremely bright lights in lit urban areas”

      I have to 100% disagree with this, urban areas have cars pulling out of side roads regularly and having a super-bright light is very effective in helping you be seen by them, I’m sure I’ve been mistaken for a moped/motorbike before. Little lights don’t cut it in the city, they get lost in the ocean of reflections.

      Having a 1000W light in the city could save your life, just point it down at an angle to avoid blinding on-coming traffic.

      Dipped head-lights aren’t too bright and nor are correctly angled bike lights.

      • Kie 28/11/2014 at 11:58 am #

        1000 Lumen that is!

      • MJ Ray 01/12/2014 at 12:52 pm #

        If a bike light has to be angled downwards then it probably isn’t a decent bike light. Good bike lights are usually put horizontally on the bars and the lens focuses the beams downwards. If you angle a light downwards, it tries to spin further forwards with each lump and bump in the road.

  4. Mark 26/11/2014 at 2:02 pm #

    It’s not strictly true that no clipless pedals incorporate reflectors: Shimano make quite a number of SPD models with either built-in reflectors or mountings for standard ones….

    • Ralph 05/12/2014 at 6:12 am #

      My clipless Shimanos and Looks don’t have reflector capability however I use stick on reflective material on the rear flat side and it seems to work, is not heavy or obtrusive.

  5. Tom 26/11/2014 at 4:48 pm #

    And remember that the red one goes on the back, I keep seeing people (particularly on the CS going through wapping/limehouse) with a red light on the front, sometimes as well as a white one, sometimes on it’s own. Saw three of them last night alone. Very odd, I don’t remember noticing anyone doing this last year..

    • Trev 28/11/2014 at 1:31 pm #

      I’ve seen that quit a few times and it has caught my eye, so as I drive a lorry in London as well as being a cyclist it cant be a bad idea.

  6. commuterjohn 26/11/2014 at 5:48 pm #

    Or have a dynamo and bolt your lights on.
    Always there and always ready, no batteries required.

    • Igor 26/11/2014 at 6:14 pm #

      A dynamo and lights with “stop function”. When you stop (e.g. at a red light) the lights remain on for a few minutes.

      • Nick 26/11/2014 at 6:29 pm #

        Agreed. Even more useful if it has a sensor to turn lights on and off when conditions dictate.

        • Sav 26/11/2014 at 10:15 pm #

          Yes, but then you have to rely on the sensor working correctly at all times.

        • Alan Moore 27/11/2014 at 10:25 am #

          I just leave mine on all the time.. doesn’t really make any difference to the riding.

      • Guilermo 28/11/2014 at 1:44 pm #

        you don’t need a stop function the dynamo will disconnect as soon as you stop peddling

        • Alan Moore 09/12/2014 at 4:31 pm #

          Guillermo he means a ‘standlight’ function.. where the light stays on for a bit even after you stop moving. Very useful at junctions.

    • Nick 22/04/2015 at 2:43 pm #

      I prefer a dynamo, AND batteries for standing at the junction. I used to have 3 D-cells fixed to my frame, that provided always enough light for that purpose. It’s basically a mag light screwd onto the frame, with cables running to the front and rear, and a bit of electronics for timing and such.

  7. Dave 26/11/2014 at 9:11 pm #

    There are some clipless pedals avaialbe out there that do have reflectors built in, my SHIMANO SPD PD-T780 Deore XT pedals for example.

  8. Darren 26/11/2014 at 9:37 pm #

    Both my pairs of clipless shoes have reflective panels in the heel. As I understand it, the shoe, attached to the pedal, is part of the pedal, and thus there is no legal issue.

    • Nick 22/04/2015 at 2:45 pm #

      Well, my pedals have reflectors, but the front reflectors have no use as they are covered by my shoes while riding.

  9. Spencer 26/11/2014 at 10:06 pm #

    I run with two different makes of lights on the rear.

    With rechargables the light can die suddenly and as you’re riding you can’t see that so better to be safe than sorry.

    • Sav 26/11/2014 at 10:14 pm #

      This is good advice I do the same. I run a cheap Cateye which runs on rechargeable batteries and have a flashing Lezyne Micro Drive.

    • MJ Ray 27/11/2014 at 10:37 am #

      Why can’t you see your light? I mentioned below that seatstay mounting is very easy to check, but if you’ve any light-coloured surface behind the light on the bike (wheel rim, racktop, whatever), then you should be able to see a red reflection at a glance unless the light is seriously underpowered. If it’s on the back of the rack, you might even be able to see the edge of the light glowing directly if it’s got 200-degree visibility.

      • Spencer 27/11/2014 at 2:41 pm #

        I use two bikes. One has a pannier rack so one light gets mounted on the rear of that, the other goes on the pannier bag. The bag itself is quite high and blocks the view of anything attached to the seatpost.

        The other is a road bike and because it has an aero seat post the only place I can fit the rear is on the frame’s rear triangle. The other clips to the backpack.

        Problem in both cases are the lights are pretty far back and low so can only see them in reflection if I pass say a car closely. I don’t constantly check so could be cycling for 20 minutes or so without realising the light has died.

        I do carry spare batteries for both types.

  10. Sav 26/11/2014 at 10:13 pm #

    The set of Knogg lights in this article are shit, I got the front one for free and it’s not great. If you want a “get you home” set get the Lezyne Femento (also available as a set).

    The front one is a 15 lumen.

  11. MJ Ray 27/11/2014 at 10:33 am #

    700 lumens??? If you’re riding off-road then you may want more, but 120 lumens is enough to see on very dark country lanes on the way home from my fenland railway station, as long as the lens isn’t completely rubbish and sending most them into the sky or hedge (look for British/German/Dutch/Danish standards approval as a rough guide).

    Avoid covering your light with your coat by putting the light on the back of the rack or a seat stay. The seat stay has the benefit that it’s always easy to check it’s on by looking back, but it seems to have gone out of fashion recently, with some lights only providing a seatpost mount.

  12. Duncan 27/11/2014 at 9:48 pm #

    Yes, please stop blinding me on CS3 Cable Street every night with those super powerful lights. Why not run a see me light on its own, then turn on your nuke powered beam when on your unlit road. Thanks!

    • Chris 28/11/2014 at 10:19 am #

      Worse still are people who insist on having nuclear powered mega-lights on strobe mode!

      I use an Exposure Diablo Mk3 on low power when commuting on CS7. I don’t know what the power output is on low setting, but I’ll assume around 100 lumens, given the relative battery life on lowest and highest (975 lumen) power settings is 1hr vs 10hrs.

      So, 100 lumens. Not madly powerful for lit streets, but powerful enough that it still casts a light, rather than being purely seen, yet I frequently get people riding behind me with flashing lights which absolutely drown my beam out!!

      Paranoid, maybe, but I actually seriously worry about what might happen if we came across an oncoming motorist who suffered from photosensitive epilepsy!!

      • sheridan 28/11/2014 at 12:58 pm #

        The chance of setting off an epileptic fit is quite low – anyone that sensitive wouldn’t have a licence:

        Far more likely is that the person driving or cycling in the other direction gets blinded, as others have said.

        • Chris 28/11/2014 at 2:13 pm #

          Thanks Sheridan. I shall stop concerning myself with that now! 🙂

          People with overly bright flashing lights are still muppets though!

        • John 17/01/2016 at 3:58 pm #

          Have you thought of those of us with epilepsy and bikes?

  13. Richard 28/11/2014 at 10:18 am #

    If you have a really bright light, please don’t use the strobe flashing setting – it’s even more dazzling that a steady-on light!

    • Chris 28/11/2014 at 10:20 am #

      Snap! 🙂

  14. John rawlins 28/11/2014 at 10:25 am #

    I use a flashing headlamp – especially useful for grabbing the attention of drivers on roundabouts and negotiating winding country lanes.

  15. David Cohen 28/11/2014 at 10:34 am #

    For commuting, I started to move away from battery powered lights, and have started using USB lights. It’s useful to get ones that have an indicator of how much power is left.

    I also carry backup lights – the get you home battery button cell type – both front and rear, just in case my USB lights run out of juice.

    USB lights are now getting more powerful and easy to take on and off the bike, with no tool fitting needed.


  16. Matt 28/11/2014 at 10:48 am #

    A classic one is not cleaning the lens of the rear lights and reflectors. It’s wet and muddy out there and those things get dirty quickly.

    • Alan Moore 28/11/2014 at 11:38 am #


      • Matt 29/11/2014 at 12:11 pm #

        I am slightly tempted to fit mudguards but I’m not sure I like the way they look on a bike, also previous (prehistoric) memory was that after market ones could rattle like a can being kicked down the road.

        • Hackney Chris 01/12/2014 at 11:24 am #

          Mudguards are a no-brainer:
          Keep the rain & road muck off your mech, thereby extending its life.
          Keep the rain & road muck off you – ever arrived at work with a road stripe up your back?
          Most importantly, they keep the rooster tail out of my face when I am following you in the rain.
          SKS do excellent mudguards for all bike types. I can highly recommend them.

  17. David Bates 28/11/2014 at 11:18 am #

    After reading about a study in Denmark a few years ago I use my lights on every ride whether it’s dark or not:

    “The project has shown that the cyclists with daytime bicycle lights have 32% fewer accidents than the control group. The effect is particularly noticeable during the summer season when the reduction is up to 40%.”

    Full details of the study can be found at

    • Alan Moore 28/11/2014 at 11:37 am #

      To be fair, this was a survey done by/for a manufacturer of retrofit dynamo lights (Reelight – I’ve tried these and they do work, although I’ve had quality issues).

      I still run daytime lights anyway, as it takes no additional effort. In fact my newest B&M front dynamo light (with a stand light on the front as well as the back) does not actually have an off switch.

  18. Richard 28/11/2014 at 12:36 pm #

    Another dumb thing to do is to mount rear lights on the pavement side not the outside: with or without a rack this often makes it hard to see from behind, especially when someone’s overtaking you or preparing to.

    • Alan Moore 28/11/2014 at 1:20 pm #

      Yes I see this often. The law actually says they should be mounted centrally or farside: so not nearside. This can be a problem with some continental bikes which are factory fitted with a front light on the left side.

      I also mount my pannier farside when I use it.. gives them a big yellow thing to go round!

  19. Trev 28/11/2014 at 1:41 pm #

    Rear lights mounted on rucksacks my pet hate, ok until you lean forward to hold the handle bars.Your back then tilts forwards then the light then shines up in the air rather than rearwards, or sometimes it ends up face to the side. Mount it on something solig that’s not gonna move.

    Happy (and safe) cycling everybody

  20. david 28/11/2014 at 4:05 pm #

    My top tip is have more than one light, especially on the back. I typically have a small flashing light on my helmet, a big static light on the rear most point , usually the pannier holder, and a flash light on the seat tube.
    From following other cyclists, a good flashing rear light gets the attention, and a bright light keeps cars from being too close. Front light needs to either light the road, or, attract attention. Mix of small flashing and big solid light usually works, but for frequent commuting on roads a small Petzl or similar on the helmet I can point in drivers faces, especially those pulling out of side roads, is the most useful.
    Stay safe out there!

    • Jim 26/12/2014 at 11:01 pm #

      I’ve had experiences with cyclists with two lights where I’ve not been able to work out where it’s one cyclist or two until I’ve been very close. Not great if you want to overtake and you’re trying to judge how much space you need.

      • MJ Ray 01/01/2015 at 1:14 pm #

        Leave the outermost light as much space as you would a small car. Why does it matter if it’s one or two riders? Drivers should be well clear of the outermost one.

  21. Jon 28/11/2014 at 4:23 pm #

    Flashing lights, yes or no? Slightly off topic but as a London driver as well as a cyclist, I often think flashing lights are a bad idea. Bad because they a) give drivers less time to judge the distance between the car and bike and b) they can easily get lost in the general mess of London lights at night, mimicking stationary lights behind railings or trees for example. In quieter environments a flashing light would certainly catch the eye. But are they best on busy urban roads? I tend to think not, or only in combination with a steady light. What does everyone think?

    • Matt 29/11/2014 at 12:33 pm #

      When driving I find flashing lights grab my attention more and immediately tell me “cyclist” so I definitely use them, I also have a solid light too though so I’m within the law (and it never harms to have a back up eh?)

      • MJ Ray 01/12/2014 at 11:47 am #

        Two problems with flashing lights: they can be missed in a short glance; they tell people “cycle” and some bad drivers think that means they don’t need to overtake properly.

  22. Mark 28/11/2014 at 5:26 pm #

    heres a few silly cyclist examples
    and here

  23. Vincent 29/11/2014 at 12:52 pm #

    In addition to lights, it’s a good habit to always wear a high-visibility jacket, even in day-time.

    Besides making you much more visible to car drivers and pedestrians, hi-viz jackets use no battery, which is a good thing in case they run off and you don’t have spare ones to get you home.

    • MJ Ray 01/12/2014 at 11:49 am #

      Fluorescent jackets seem to confer no benefit in practice (motorists failing to look is a bigger problem than looking but not seeing in time) and they have the drawback of being yet another piece of special kit to lug around and make cycling less convenient.

  24. russell 29/11/2014 at 8:02 pm #

    good suggestions. I unfortunately forget to unclip my front light and it was knicked…wont be doing that again!

  25. SombraCycle 30/11/2014 at 6:34 pm #

    Typical bicycle tail lights are high intensity but can only be seen from behind and are often blinding to car drivers and other cyclists. This is dangerous, especially while cycling in urban areas with low lighting. I have been working on a product to mitigate this blinding effect as well a give you some side visibility with any standard tail light; its a tail light diffuser, since Im not producing this yet and now finalizing the design I would love if you could drop a comment.

    check it out here 🙂

    Also a 20sec funny video of riding in Kensington Gardens!KnightRiderSpoof/c8vu

    Cheers, Ofer Canfi

  26. Tom Judd 09/12/2014 at 4:22 pm #

    “no clipless pedals actually incorporate this into their design”: see, for example,

Leave a Reply