New to BLF and to this thread, wondering if this project is still alive, but nevertheless, would like to add my view on the topic, because I’ve been a relatively budget aware bicycle lights enthusiast for years, having bicycle lights on basically at all times for my own and others safety and also to see in the dark whether it’s riding on country roads or off-roading on trails.
My thesis is that bicycle lights should cover pretty much the same basics as standard, road legal motor vehicle lights, only smaller in size and lighter in weight. What I mean with the lights basics is that there needs to be different functions and different kind of beams of the light for different occasions, not just one beam with various levels of brightness. Constant flashing let alone different colors than white (which can be of different color temperatures, make no mistake) are a total no-no. Rear lights are not that much of an issue, they just need to be steady and bright enough to show your location, which is easily achieved because red LEDs show very well even at very low sub 1 Watt power levels, a little brighter brake light with motion sensor is ok too, but rear lights are really not a problem anymore, you can buy them from supermarkets, they cost next to nothing and you’re fine with them. Other lights, like extra safety lights visible from the side are not necessary at all, orange or white retro reflecting ‘cat-eyes’ cover that need for visibility in darkness more than well, active safety from passive technology, so to say.
First and what is probably needed the most in running hours would be a daylight running light, it has only one requirement, to be bright enough in daylight to be visible to others, something like 100-200lumens of omni-directional flood light, not too much dazzling, but bright enough to be seen from reasonable distance in daylight. The daylight running light should probably have two or three different brightness levels, that could be automatically switching via sensor due to ambient brightness, less brightness in dull, grey day and more brightness for the bright sunny day and optionally an extra low brightness mode for the dusk, where you still don’t need light to see where you’re going, but ambient lighting getting lower the less brightness is needed to be seen by others. Possibility to manually flash the daylight running light at higher brightness to gain momentary extra attention would be desirable, but not necessary, if the light has high-beam mode that can used for that.
Second, there needs to be low-beam, often referred to as StVZO, cut-off beam etc. Anybody with a driver’s license and motor vehicle driving experience knows the concept of low-beam, it’s a light beam that is optically suppressed from emitting too much light above certain horizontal line to save oncoming traffic from getting dazzled to provide safety in traffic. Unfortunately the LEDs got very bright in very short period of time and they were applied to cheap bicycle lights willy nilly without thinking, that bright LEDs with small surface area are very much dazzling to others even at low levels of sub 100 lumens or so, let alone several hundreds of 1000+. This has been fortunately solved partially by German and French legislators that have not been sleeping on it (Netherlands has some legislation also, maybe elsewhere too, but not globally yet) and have created standards that take the beam shape into account for bicycle lights above certain levels of brightness, which is why we bicycle light enthusiasts have even a possibility to be responsible and not dazzle the others by choice.
Third, there needs to be adequate high-beam equivalent light mode too and preferably not only one kind of beam, but at least two. Bicycle riding in darkness requires high-beam option like any other riding or driving to be able to see properly as needed. The high brightness is less of a requirement, than the optics to direct the beams in useful ways specific for bike riding. On road bike you may ride on empty roads at relatively high speeds, which means that you need to see a realitvely long distance ahead of you to be able to detect the road and any possible obstacles or changes in the road so that you have time to react in order to dodge, slow down or even stop, hence you need more or less of a spot light beam not extreme and preferably not fully round circular, but somewhat oval, that can show a little bit of the sides, while shedding the light straight ahead with a decent throw. But there are other use cases for high-beam equivalent bicycle headlight too, those cases you’re riding slower on poorer roads, gravel, trails, cross country even, you want to see well, but you don’t need so much throw, though some is okay, as you need to see your surroundings and be able to detect winding corners, steep ups and downs at short distance. Hence you need something like an ovalesque mix of semi-spot and semi-flood for that. This feature would be cool, if the light had a speed sensor similar to a bike computer for example that would enable automatic change of beam type according to the speed, so when riding fast the light would dim the semi-flood and brighten the spot and again when going slower the spot would dim and semi-flood would be brightened. High beam should also have a manual flashing made easy so that you could flash them as needed for extra attention, just like you would driving a car.
Other things to be taken into account. External batteries are a must, they enable scaling the amount of watt hours you might need for your rides. 12V system is preferable aka 3 in series (3S) lithium-ion battery packs, 3 cell, 6 cell, 9 cell, even 12 cell for longer rides at night. Higher voltage is generally better, because it means less amps, hence puts less strain on the components. It’s also better to use more LEDs and pump out insane lumens out of them to save the light from the heat, I think 50% of the LEDs maximum lumens is quite enough, despite it increases the amount of LEDs needed to get higher brightness, but like said, huge brightness is not as important as proper optical direction of the beam. I would say for daylight running light 100-200lumens of omni-directional, hemispherical beam is more than enough and for that there can be as many LEDs as needed, from top of my head I’d say 10 fairly low power LEDs would be quite ok. For low beam, adequate amount of lumens would be something like 400-600lm with for example 100lm per LED or so 4-6 LEDs in total, small in size and precise in beam, beam optimally optically directed so that the light is where the cyclist needs it the most, on the road, mostly forward straight ahead, fading smoothly to the sides to cover adequate width of any regular roads while catching the sides and corners within a reasonable distance, whihc doens’'t have to be too far. For high-beam there could something like 2000-400 lumens, that could be manually adjustable within range from 500lm to 4000lm, so that if you don’t need that much light, you could ave some battery, and if you need all the brightness there is to put out, you could blast it on as you wish.
All in all, bicycle lights are a special kind of vehicles lights, they should conform to any legal vehicle lighting concepts, but with the great difference that they need to be reasonably light in weight, including the light unit and its power source. There’s a challenge to meet indeed, but I’m sure it’s not impossible to achieve, though it may require taking shortcuts on the way and not all goals are achievable in their full glory, yet the concept and goal must be ambitious and not dilute it with too many compromises to make the end product seem like it was designed by commission.
Lights that I wish people would study as examples of interesting implementations of vehicle lighting concepts in bicycle world are: Supernova M99 series, the Pro versions aka ones with low-beam, high-beam functionality. Supernova is the leading manufacturer in implementing the low-beam and high-beam in their lights. Other interesting ones are B+M IQ-XL, also a low-beam, high-beam light made for e-bikes, but if you know how, you can make them work with an external battery without an e-bike as well, not a problem. There’s also Herrmans Nordic Extreme 12V e-bike light that has low-beam, high-beam functionality. Other lights of interest, which unfortunately lack the low-beam, but have interesting concepts neverthless are K-Lite Ultra, a dynamo powered high brightness “adventure light”. There are also a plenty of cut-off beam lights be it battery, e-bike or dynamo powered that have no high-beam and equally great numbers of off-road lights, basically all a little higher brightness, say ~500lm or more can be counted in, that can serve well in darkness but are totally a nuisance to others in any oncoming traffic.
Links:
- Supernova’s high-end battery operated bicycle light: M99 Mini Pro B54
- Supernova has also similar dynamo operated M99 version: M99 DY Pro
- Busch+Muller’s giant low-/high-beam e-bike model: IQ-XL High Beam
- Herrmans only model with high beam that I know of: Nordic Xtreme
- k-Lite dynamo light without low-beam, but interesting: k-Lite Ultra v2
- Crown funding started maker of interesting bicycle lights: Outbound
- Compact high power lights with interchangeable optics: Gloworm
- Sigma’s 2000lm off-road classic w/ quality optics: Buster HL2000
- My favorite basic cut-off beam dynamo light: Herrmans MR-8
Of these examples what I would like to see as a BLF cost effective competitor and equivalent in functionality would definitely be Supernova M99 B54 Pro, it has almost all I can hope for, compact light unit, low-beam high-beam with wired remote switch, 12V aka 3S battery, different brightness modes to choose from. What I don’t like about Supernova M99 B54 Mini Pro is price, obviously, though it’s justifiable, because Supernova’s build quality is pretty high in the world of bicycle lights and guarantees are long for a reason, they do trust their product, but the price is a bit hefty for a bike light nevertheless. Another thing is their matrix optics, which is far from perfect.
I have myself M99 Mini Pro 25, an e-bike version with external 12V voltage regulated custom battery on a normal bike and despite I adore the low-beam high-beam functionality, the beam is a bit too wide, lacking central bias and due to the matrix reflector there’s a kind of a checkered pattern in the projected beam which is disturbing to the eye when riding in darkness. Another annoying thing, common to all above listed high-beam capable lights is, that they work a little different from motor vehicle lights in a sense that low-beam is constantly on, aka when you switch to the high-beam, the low beam stays on lighting the foreground too much and the high beam seems weak on top of that, but will of course shed light a bit further, only that the difference to the low-beam isn’t that big because of too much light in the foreground. One thing that I would like to see different in the implementation of the high-beam is that the low beam would be turned off and the high beam would be double or triple the lumens of low-beam to make real difference.
If there are any other who done their home work about bike lights and probably road legal vehicle lights in general, please feel free to have some input. Or if you’re someone who hasn’t studied bicycle or vehicle lights in general, but are curious and interested in lighting bicycles, please help yourself and study these examples listed above, of lights that represent somewhat the leading edge of the bicycle lighting today. There are others too, some similar, some more expensive, some higher brightness, some more exclusive etc. etc. I just didn’t want to make too long of a list for starters, just focus on the main concept that I think bicycle lights should be made conform to.
TL;DR? Guess my motto for bicycle lights would probably be something like:
“A proper bicycle light has exactly the same requirements as any other road legal vehicle lights, only in flashlight equivalent scale, if not even lighter in weight.”
EDIT: Forgot to add that a dynamo hub powered backup low-beam functionality would be useful if not even mandatory for those times that the batteries simply run out of charge and you’re in the middle of nowhere in pitch black darkness in desperate need to find your way. Dynamo hub could and probably should be also power source for the daylight running light, so you’ll save max. battery runtime for actual need for the dark hours. Dynamo hub should be always used in conjunction with the battery operated lights, just because the dynamo power never runs out of charge, where again batteries can offer higher power normally for seeing in the dark, hence they cannot be held mutually exclusive in anyways. Dynamo hub can even be used to charge the batteries in the worst case scenario, if there are no other sources available during the day.
. I really want to see future updates of that your bike light project.
