Viewing 40 posts - 1 through 40 (of 44 total)
  • Has anyone made/bodged a light diffuser/deflector/reflector for use on the road?
  • IHN
    Full Member

    Dark nights and mornings for the commute are imminent and I have some C&B Seen 1000lm lights that are good and bright and will last the time easily. However, I’m aware that their beam pattern is ‘massive glaring spot’ and much as I dislike car drivers blinding me with full beam, I’m sure they think the same.

    Plus, as much of the commute is unlit narrow country lanes, blinding oncoming drivers is probably not the safest course of action anyway.

    I was thinking of bodging some kind of hood over the light using something like a piece of old Coke can cut to a ‘baseball cap peak’ sort of shape, zip tied round the light. Anyone done anything similar?

    philjunior
    Free Member

    All that will do is reduce the glare in your eyes, won’t really sort the beam out.

    Bez
    Full Member

    I tried a few things.

    A hood doesn’t do anything, really. If you want to send a decent amount of light into the distance, forget it. You’re still going to dazzle people.

    A Fresnel/diffuser like the above (and like the one on the Exposure Strada) simply turns a circular beam into an elliptical one; it still results in a hot spot that’s closer than you’d like and a load of light going above the horizon. As above: if you want to send a decent amount of light into the distance, a diffuser won’t help prevent dazzling.

    There’s only one way to get a proper road-friendly beam (lots of light up the road, less at close distance, and very little above the horizin), and that’s to get a light where the LED isn’t fired forwards and gathered up by a conical reflector, but is fired into a properly shaped reflector. And that means an StVZO-compliant German/Dutch light.

    Kahurangi
    Full Member

    Cheers for the experimenting Bez, I was about to launch in to some similar trials myself. I have a small shelf full of P7 torches that I would have loved to make more socially acceptable!

    forzafkawi
    Free Member

    I have built several lights in the past and have a friend who does likewise. He has experimented with some success with creating a reflector where the LED fires backwards into the reflector to produce a more focussed beam i.e. less spill which is what tends to dazzle oncoming drivers. It has taken him a long time and many prototypes to get the reflector shape to provide a usable beam. He gets a very defined cut-off at the top of the beam much like the B&M lights.

    I personally am experimenting with Fresnesl lenses and am very encouraged by the results. You get a very focussed square beam with massive throw compared to just optics and very little spill. Great for road use and it doesn’t seem to dazzle oncoming drivers because the beam is so focussed. The square pattern is a result of the projection of the LED die and actually becomes trapezoidal when shone at an angle such as on the road ahead.

    I am currently developing a double XM-L version where the two beams are focussed separately to provide a “corridor” of light effect on the road.

    forzafkawi
    Free Member

    I just had a look at the C&B Seen diffuser linked to above and the Exposure Strada and neither of those are using Fresnel lenses. I agree that a diffuser will just spread the light which is not what you actually want.

    A Fresnel lens is constructed as a series of concentric rings which actually focus any light passing through with very little diffusion (if any). The downside of that is you can almost get too focussed a beam but by altering the distance between the lens and the light source (i.e. LED) you can actually control the light pattern. Glass Fresnel lenses are used in lighthouses because they are so much more compact (and lighter) than the equivalent aspheric lens.

    There are torches on the market now that use aspheric lenses to provide the same focussing power and you can twist a mechanism on the front to alter the focal point and hence the light pattern.

    MartynS
    Full Member

    I’ve put some diffuser on the inside of the glass of my light.
    It’s now far less spot and more flood. If you’re properly off road just put it on high power and it’s a nice light.. On the road turn it down!!

    I’ll post you a bit of diff to try with!

    Bez
    Full Member

    The problem with the “just turn it down on the road” approach to using a scattergun light is that if it’s turned down enough that it’s not dazzling people then it’s not bright enough to ride at any useful speed with. (IME/IMO, anyway.)

    neither of those are using Fresnel lenses

    Yes, you’re right, I done a confoosed: When I briefly had a Strada I cut a 5p-sized disc out of a Fresnel to place over the diffuse beam, so that the diffused beam was aimed lower than the main beam.

    I notice the Mk6 has a different design… *shuffles off round the web*

    IHN
    Full Member

    Fresnel eh…?

    *wonders if he can do something with one of those headlamp beam deflectors what you get for driving on the continent*

    molgrips
    Free Member

    I have this problem. I bought one of those lateral fresnel diffusors. It makes a big letterbox of light. At first this looks ridiculous, but fitted to the bike and ridden for a bit it actually makes a lot of sense. You can adjust it low enough to not dazzle drivers, and it throws the right amount of light the right distance, with no overspill. Pretty good. However I want to use it as both road light and helmet light for off-road, where the letterbox is useless.

    The spot though is similarly easy to avoid dazzling with, because it’s so narrow. You can aim it onto the road surface about 30m or so away, which is enough to ride by but doesn’t dazzle.

    I bought one of those credit card fresnel lenses, and cut a circle out of it – worked, except it left a dark hole in the middle, and was a bit too diffuse. So I cut most of the middle out of it, leaving about a cm width ring, and it’s spot on now – pun intended.

    TBH at £15 I might buy another lamp and fit the letterbox lens to it permanently.

    forzafkawi
    Free Member

    Bez – Member

    The problem with the “just turn it down on the road” approach to using a scattergun light is that if it’s turned down enough that it’s not dazzling people then it’s not bright enough to ride at any useful speed with. (IME/IMO, anyway.)

    You are correct there. The problem with most of the bike lights on the market these days is that they are not specifically designed for on the road use. By that I mean they don’t have a focussed beam which stops blinding oncoming drivers.

    Fine for use off-road where you want a floody beam and probably 1000+ lumens but on road you are probably wasting 50% of your light power illuminating the trees and bushes at the side of the road.

    I have done a lot of light building using all sorts of LEDs and optics and believe you me, the optimal combination just does not exist for (unlit) road use. Interestingly the closest I have come is using the older XP-G LED which is less powerful than the latest XM-Ls but has a smaller die which is easier to keep a focussed beam and hence less spill to dazle oncoming drivers.

    The big problem now is that most manufacturers seem to be using XM-Ls in their light designs because they are more powerful and more efficient so they are getting higher lumen values and longer runtimes. Unfortunately unless someone comes out with a radical reflector design the latest lights cannot avoid a lot of spill which is going to anger more and more drivers. As you say, tilting the light down does very little to help the situation and makes having the more powerful light pointless.

    Cateye have a range of lights now which are quite affordable for their claimed power output but are almost certainly based around the XM-L LED. That’s not to mention the myriad of cheap Chinese lights around as well like the Magicshine and NiteFighter.

    People need to understand that all these lights are not really suitable for use on road. If we are not careful, with the proliferation of badly designed lights we could end up with controlling legislation like Germany where they are limited to very low power lights that have to have a very sharp cut-off to prevent dazzling oncoming drivers.

    Fine you might say but it’s not fine because these lights are feeble. Okay to be seen by riding in town where there is extra street light illumination but on unlit roads they are positively dangerous. I bought one just to examine the design of it and whilst it is an interesting design, the illumination level is pathetic.

    IHN
    Full Member

    I bought one of those credit card fresnel lenses, and cut a circle out of it – worked, except it left a dark hole in the middle, and was a bit too diffuse. So I cut most of the middle out of it, leaving about a cm width ring, and it’s spot on now – pun intended.

    Got a pic?

    Bez
    Full Member

    People need to understand that all these lights are not really suitable for use on road. If we are not careful, with the proliferation of badly designed lights we could end up with controlling legislation like Germany where they are limited to very low power lights that have to have a very sharp cut-off to prevent dazzling oncoming drivers.

    Fine you might say but it’s not fine because these lights are feeble. Okay to be seen by riding in town where there is extra street light illumination but on unlit roads they are positively dangerous. I bought one just to examine the design of it and whilst it is an interesting design, the illumination level is pathetic.

    Are you about a decade out of date or are you just buying rubbish lights? Decent StVZO-compliant lights (dyno or battery) are plenty powerful enough for fast road riding and have been for a few years now.

    forzafkawi
    Free Member

    Bez – Member

    Are you about a decade out of date or are you just buying rubbish lights? Decent StVZO-compliant lights (dyno or battery) are plenty powerful enough for fast road riding and have been for a few years now.

    Maybe I am out of date or maybe your definition of fast road riding differs from mine? I’ve yet to see a dynamo powered light which gives any sort of useable illumination on unlit country roads but I’m eager to learn. Please forward an example of one of these modern StVZO lights which performs miracles please.

    BadlyWiredDog
    Full Member

    Are you about a decade out of date or are you just buying rubbish lights? Decent StVZO-compliant lights (dyno or battery) are plenty powerful enough for fast road riding and have been for a few years now.

    +1

    I have a Philips Saferide and a Supernova Airstream, both work fine on the open road, I still a Joystick next to them to act as a high beam when there’s no oncoming traffic. I also have a 2014, I think, Strada which is acceptable if you aim it slightly off to the left and down a little.

    I run the Airstream – it’s Joystick sized – as an additional bar light on mixed up mtb rides so that I can ride road sections without dazzling the heck out of oncoming traffic.

    I’ve also tried experimenting with hood, as several people have said already, they’re near useless as is angling powerful flood beams downwards.

    damitamit
    Free Member

    I agree with Bez. My dynamo powered B&M Cyo has been fine for loads of fast unlit road riding. Descending fast with it is fine. I’ve even gone over hardknott in the dark and pissin rain with it.

    forzafkawi
    Free Member

    BadlyWiredDog – Member

    Are you about a decade out of date or are you just buying rubbish lights? Decent StVZO-compliant lights (dyno or battery) are plenty powerful enough for fast road riding and have been for a few years now.

    +1

    I have a Philips Saferide and a Supernova Airstream, both work fine on the open road, I still a Joystick next to them to act as a high beam when there’s no oncoming traffic. I also have a 2014, I think, Strada which is acceptable if you aim it slightly off to the left and down a little.

    I run the Airstream – it’s Joystick sized – as an additional bar light on mixed up mtb rides so that I can ride road sections without dazzling the heck out of oncoming traffic.

    I’ve also tried experimenting with hood, as several people have said already, they’re near useless as is angling powerful flood beams downwards.

    So let me see if I’ve got what you are saying right. A 70 lux light and a 205 lumen light are fine but you still need a 700 lumen Joystick to see further ahead?

    nedrapier
    Full Member

    I did this with a plastic milk bottle. It didn’t really help a great deal – look at the angle between where the LED is within the housing and the lip of the shroud – there’s still going to be loads going up and out. I bent the lip down a bit and pushed it forward (that’s just a zip tie) – I think it was an improvement, just not as good as I’d hoped.

    It did diffuse a nice chunk of light out to the sides though, which is good. Had to put some black tape on the top, because it was too bright under my face.

    molgrips
    Free Member

    Are you about a decade out of date or are you just buying rubbish lights?

    You do need quite a lot of light when riding at 30mph down a dark unlit road in the wet with potholes etc. The thing you have to remember about tarmac is that it’s black, which doesn’t make for much visibility. Having done an awful lot of night riding on road, I can say it’s much easier with decent lights.

    And I’d also say the sharp spot of the lights I think the OP has is your best bet. It throws a long way down the road, and is concentrated, which means you can happily cycle around on low, and that in turn means the side spill is much less.

    thisisnotaspoon
    Free Member

    So let me see if I’ve got what you are saying right. A 70 lux light and a 205 lumen light are fine but you still need a 700 lumen Joystick to see further ahead?

    Sounds about right, the German lights are only illuminating about 1/3 of the cone that the off-road lights are, so only need to be about 1/3 the power.

    jameso
    Full Member

    Maybe I am out of date or maybe your definition of fast road riding differs from mine? I’ve yet to see a dynamo powered light which gives any sort of useable illumination on unlit country roads but I’m eager to learn. Please forward an example of one of these modern StVZO lights which performs miracles please.

    Have a look at the Edelux 2, or the B+M IQ that uses the same reflector design. The only time I need more light than the Edelux 2 puts out is on very tight, fast corners where the beam width isn’t quite wide enough. At any other time it’s hard to imagine how it could be any better – beam pattern and output is not far off a single car headlamp on dipped. Certainly way ahead of any high lumen torch-beam light I’ve used. The L+M Secca 1300 I have has a good beam pattern via multiple LEDs, a bit better for tight corners, but the Edelux is still a long way ahead overall, imo.

    forzafkawi
    Free Member

    jameso – Member

    Maybe I am out of date or maybe your definition of fast road riding differs from mine? I’ve yet to see a dynamo powered light which gives any sort of useable illumination on unlit country roads but I’m eager to learn. Please forward an example of one of these modern StVZO lights which performs miracles please.

    Have a look at the Edelux 2, or the B+M IQ that uses the same reflector design. The only time I need more light than the Edelux 2 puts out is on very tight, fast corners where the beam width isn’t quite wide enough. At any other time it’s hard to imagine how it could be any better – beam pattern and output is not far off a single car headlamp on dipped. Certainly way ahead of any high lumen torch-beam light I’ve used. The L+M Secca 1300 I have has a good beam pattern via multiple LEDs, a bit better for tight corners, but the Edelux is still a long way ahead overall, imo.

    I’ve got an B&M IQ and that is pathetic. If you guys think 80-100 lux is fine for fast road riding on unlit country roads then all I can conclude is that you must have better eyes than me (and all my mates incidentally who also think it’s a joke).

    I will admit it’s an interesting design of light but just needs to be at least three times more powerful. The beam shots on the B&M website are also highly flattering in my opinion.

    There’s not really much point with continuing this discussion on that basis.

    piedidiformaggio
    Free Member

    Have a look at the Busch & Muller Lumotec Lyt

    The lens on that directs the the bulk of the light into a trapezoidal shape infant of you, so might work. Of course, difficulty is that it’s designed to work with a single bright LED and reflective bowl, so would need a fair amount of bodging

    HoratioHufnagel
    Free Member

    I used a Exposure Maxx-D to commute with for a few years on unlit roads. Eventually i got fed up of dazzling people and angling it down/turning it to low every time a car went past and bought a Cyo Premium 80 lux (http://www.bike-discount.de/en/buy/busch-mueller-lumotec-iq-cyo-premium-t-senso-plus-140907) which is fine for unlit fast road riding up to around 25mph. Probably wouldn’t want to go much faster than 30mph without an additional light, but i’ve rarely found that to be a problem.

    They appear to have a brighter 100 lux version on the way too.

    STATO
    Free Member

    I’ve got an B&M IQ and that is pathetic. If you guys think 80-100 lux is fine for fast road riding on unlit country roads then all I can conclude is that you must have better eyes than me (and all my mates incidentally who also think it’s a joke).

    Have you got the standard B&M or the Premium? 100lux is fine, its way more than most people used for years. If all your mates ride with 1000Lumen then it might seem like less, but then most fast club riders i know ride around with cheap cateye lights and survive by latent talent.

    thisisnotaspoon
    Free Member

    There’s not really much point with continuing this discussion on that basis.

    Have you got the standard B&M or the Premium? 100lux is fine, its way more than most people used for years. If all your mates ride with 1000Lumen then it might seem like less, but then most fast club riders i know ride around with cheap cateye lights and survive by latent talent.

    I used to ride the peaks with one of these.

    Fine even at 30mph, it’s enough to reflect off cateyes and white lines, just a bit scary when an oncoming car blinds you just before a bend!

    Bez
    Full Member

    Er, well, I’m quite happy on 30-40 mph descents with my Cyo Premium or my Luxos U, and I was fine with the Cyo 60 before that. And I’ve ridden with plenty of people who’ve used similar or who’ve noted that they all chuck out plenty enough light. General consensus seems to be that they’re just fine and dandy.

    Of course MOAR PHOTONZ is better, assuming they’re sent to the right place, and of course that’s especially true in the wet, but to claim that “on unlit roads they are positively dangerous” is just a little bit hyperbolic. I say hyperbolic; frankly, I mean plain wrong.

    But I see there is NO POINTS IN DISCUSHUN so whaaaatever 🙂

    If you guys think 80-100 lux is fine for fast road riding on unlit country roads then all I can conclude is that you must have better eyes than me (and all my mates incidentally who also think it’s a joke).

    What is it, Velo Club des Retinas de Merde or something? 🙂

    MoreCashThanDash
    Full Member

    For £60 I got a B&M Core from Rosebikes. Seemed easier, is amazing on road.

    BadlyWiredDog
    Full Member

    So let me see if I’ve got what you are saying right. A 70 lux light and a 205 lumen light are fine but you still need a 700 lumen Joystick to see further ahead?

    In the same way that car dip beams are perfectly useable, but when there’s no oncoming traffic, a higher beam gives better vision ahead when you’re not going to dazzle oncoming traffic. It’s a fairly easy concept to understand.

    Northwind
    Full Member

    I have a couple of cheap XML torches – I bought them for mtb but they turned out to be pretty rubbish, too tight beamed. That ironically makes them ideal for hte road. The bar one is aimed low enough to avoid glare, the helmet one similiarly aimed down from my sightline so I don’t just automatically laserbeam everyone I look at. But, it’s also useful to be able to hit drivers with the searchlight from time to time so I’m very happy that it has the potential to blast.

    midlifecrisis
    Free Member

    I’d be interested to hear any real world comparisons of a generic 1000 lumen light against a B+M 80 lux light.

    I understand that they are different measures of lights but how do they compare?

    I do a lot of riding in the dark on unlit roads so value having a good view of the road ahead but don’t like feeling that I am dazzling cars when they pass. Has anyone previously used a 1000 lumen set up and gone to a B+M 80 lux road-specific system? How do they compare?

    thisisnotaspoon
    Free Member

    I’m just guessing but as dynamo’s output a constant power (2.4W or 3W) and it’s purely down to the lamp’s efficiency how bright it is, that a 100lux light is about the same power as a 600-800lumen lamp (the ratings for a supernova E3 triple and Exposure Revo respectively).

    The difference being that the dynamo lamps spread that light low and wide rather than in a cone.

    Secondly, brighter lights don’t really offer much advantage on the road IME, I had some Q5 LED Torches (~200-250lumen) when LED torches first became popular, which had more than enough ooomph for riding quickly.

    Thirdly, anyone remember these?

    For a good while they were the only affordable option! Maybe some people are just spoilt by the though that a 900lumen P7 lamp is the poverty option for night riding!

    ransos
    Free Member

    I’ve got an B&M IQ and that is pathetic. If you guys think 80-100 lux is fine for fast road riding on unlit country roads then all I can conclude is that you must have better eyes than me (and all my mates incidentally who also think it’s a joke).

    I must have better eyes than you, then, because I do a lot of night road riding and find the B&M to be great.

    Has anyone previously used a 1000 lumen set up and gone to a B+M 80 lux road-specific system? How do they compare?

    I have a 1000 lumen smudge light and a B&M Ixon IQ premium. The smudge light has a far brighter hotspot, but the B&M provides an even, wide beam with a definite cut off at the top.

    garlic
    Free Member

    Most performance LED lights are overkill for the road. If you need really need a bright light for off-road or poorly lit sections of your journey then I’d suggest putting it on a low power setting and angling it downwards so it doesn’t shine directly at oncoming traffic.

    midlifecrisis
    Free Member

    Thanks ransos – very helpful reply.

    I’ll be looking for a B+M light next time I need a replacement.

    jameso
    Full Member

    I’d be interested to hear any real world comparisons of a generic 1000 lumen light against a B+M 80 lux light.

    I understand that they are different measures of lights but how do they compare?
    I’ve used a number of chinese ‘1000’ lumen lights as samples, a few good L+M 1000-1400 lumen lights and an Edelux 2, 70-100 lux I think.

    The Chinese lights can have a bright hotspot but tend to have a poor / typical tunnel shape beam pattern so 1000 lumen or not, could be 2000, the spread isn’t much good. The output can make them perfectly workable though, have done plenty of night miles on lights like that.

    The L+M multi-LED lights are a long way ahead of the torch-beam jobs. If the chinese 1000 lumen lights are really 1000 (they’re probably not imo), the L+M Secca 1400 seems very, very bright for ~1400 L. It’s still brighter on the half-power 700 L setting.

    The Edelux at around 80-90 lux (approx output at 18mph) is a better road light imo. The light concentration / spread over the ~100 yards in front of you is more even, there’s no tunnel-effect either. It’s less tiring on a long ride. The total light output over the area you need it is about 2/3 of the L+M Secca 1400 on full I’d say, but it’s enough for fast road use on Alpine-grade descents (ime).

    T1000
    Free Member

    not quite what the OP asked.. however the excellent Lumicycle range include lots of lights with glow rings etc + optimised for roed use

    nbt
    Full Member

    I used to use Lumicycles with glow rings back in the days of halogen bulbs and NiMH batteries. The issue I had then (and that I have with lights I’m looking at now) is that the constant glow on the bar distracts my vision (maybe it’s me), and if I am out of the saddle, I can get a faceful of lumens. FOr the Lumis, I fashioned an evebrow, but ideally I’d like something built into a properly designed light

    has anyone got any real world experience of the new Blaze laserlight? looks useful from a city commuting “be seen” viewpoint rather than an out on the road “see by” view though

    http://www.blaze.cc/laserlight/

    Bez
    Full Member

    has anyone got any real world experience of the new Blaze laserlight?

    Voilà:

    Gunpowder, Gelatine, Cycle Light With a Laser Beam

Viewing 40 posts - 1 through 40 (of 44 total)

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