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These web pages are about 2 things: Dynamo based bicycle lighting (of which the headlamp has a cutoff), and seeing how that can and will improve. For the latter part I experiment with LED light colours, types, drivers, battery powered lamps and headlamps without cutoff. This also means experimenting with headlamps for mountainbiking, but it is not my intention to make an overview of lighting for nighttime mountain biking. I don't have enough headlamps to play with for that, and I would need to make a trip to suitable terrain for that which is not close to where I live. I do have a suggestion for a big improvement in MTB headlamps, as I told at the end of 2010 already on the page where I describe my experiences with the Lupine Betty, namely a cutoff beam with more light above the horizon. This would be much better as in particular the problem with symmetric beams is the overexposure of the near field, but also you don't need as much light going up as on the road/trail surface...
My original introduction of 2008: This is a test of bicycle lamps and related matters I came across, dealt with in a way it should be done, with subjects I've not come across in tests on the web and in particular bicycling magazines (e.g. the Dutch magazine 'Fiets'; I mention that magazine because on their web forum I suggested the methods in the list below as something they should use in tests/reviews; the lack of interest from them resulted in these webpages...). An example of something I didn't come across but that I find essential, is the vibration from the hub dynamo. Note that I only put stuff in this test that I bought or otherwise have regular access to. Other materials I judge on technical merit as best as possible.
Here's a list of essentials when examining bicycle lamps (I mentioned most of these points already on 2007.09.20 on the forum of the dutch bicycling magazine Fiets, i.e. http://forum.fiets.nl, in a discussion on lighting):
From all the testing and analysing that did, I identified lots of problems, and shared that information on this site and with manufacturers but almost none even responded and only 1 bicycle light maker was interested, Philips (but only because the person responsible for esp. marketing at that time was interested in really using my suggestions to make better lamps)... As the guy responsible for marketing Nuvinci in NL found out: The bicycle inducstry is extremely conservative and thus disinterested in improvements...
lumen = amount of light.
lux = amount of light that is projected onto a surface, divided by that surface area.
For the determination of visibility and what happens with direct light into the eye (a lens with photoreceptors behind it), are used:
candela = amount of light per steradian (solid angle), coming from the emitter
candela/m^2 = amount of light per steradian (solid angle) coming from a given area of the emitter, divided by that area. [ This is the measure of visibility and particularly important for taillamps. ]
Example: When lamp 1 has the same amount of lux as lamp 2, but lights up an area twice as large (assuming homogenous distribution of light, so each spot gets the same amount of light) then lamp 1 has an output twice that of lamp 2, i.e. the lumen number is twice as high.
N.B. I say in the above 'amount of light', but light is not static, so of course I should say something like light current, but the way I wrote it above is clearer and doesn't need a lot of explanation to see the difference between lumen and lux, which is what's most important.
So a lux rating depends on the distance at which you measure (and on how you project, onto a wall, or onto the ground). In a divergent beam, it increases if the distance to the measuring device is made smaller. When on these pages I mention the lux rating of a lamp, it will usually be with regard to the StVZO measurement setup, which measures bicycle headlamps' beam patterns projected onto a wall at 10 m distance, and the brightest part of the beam is that lamp's lux rating.
Note that this lux value is not the value that you will see on the ground when cycling, because when cycling light is spread out over a much larger area on the ground. The lux ratings on the ground are therefore much lower. When looking at the entire beam pattern it's usually on average (lumen divided by surface of the beam) around or below 1 lux on the ground. For example, take the Philips Saferide 80, which has a light output of about 270 lumen, though part of that goes upwards in the artefacts. The surface the light is spread over is about 7 m (width) x 70 m (length) so the average lux value is only 270/490 = 0.55 lux at best, more if aiming the lamp closer. This is an average, and close to the bike the lux values are higher than far away and the beam strength drops off to the left and right, but still I would guess in the centre fairly close to the bike that it's a few lux at most.
Candela values and luminance are of use to determine in particular how well visible, but also how annoying a lamp is. This is because of the way the eye works, with a lens, and because in case of annoyance and visibility it's generally about light going directly from the lamp to the eye. What one needs to look at for direct view of a light emitting subject, is actually the light density in candela/square metre (light going into a specific direction, divided by the area of the emitting surface). This is explained further in the section on luminosity and luminous intensity and more.
The terms headlamp and headlight have the same meaning but some people use headlamp also for a head-mounted lamp, which is confusing, so I will treat headlamp and headlight as exactly the same, and I will call a head-mounted lamp a head-mounted lamp :)
Taillamp and taillight again mean the same, and here there is no confusion possible with a head mounted taillamp. They are not not really used I think, and not needed, as for a head-mounted lamp the rationale is that you can aim where you need which can be useful in corners and in rough terrain. For taillamps this is pointless and people just ride with a fixed taillamp on the bike but perhaps there are some dual lamps (headlamp + taillamp in one) that are head-mounted?
Dynamos: Voltage, current, dynamo types and overvoltage protection.
In the early 80s, halogen bicycle lamps were appearing. The were noticeably brighter, but in a city it really doesn't matter that much how much light you've got; By this I mean: More light is better, but poorly lit roads where you need a lamp to see the road (to avoid broken off branches etc.) are uncommon (in the Netherlands at least!). That was the case then as it is now, it was quite difficult then to find a bit of unlit road to compare a standard incandescent bulb to a new halogen one! In the city, the main advantage of plenty of light (plenty means much more than a halogen headlamp btw.) is comfort, it's easier on the eyes (e.g. car headlamps are less annoying as your eyes are accustomed to the amount of light from your own headlamp) and allows you to evade bad patches in the road.
Real progress was only made from ca. 2007, with high power LED lamps using in particular the Seoul P4 or Cree XR-E Q5. Examples of these are the Schmidt Edelux, Supernova E3, Busch & Müller IQ Fly (which was superseded since October 2008 by the IQ Cyo in the regular and near-field versions). On this webpage I started in 2008 with a description of in particular the Schmidt Edelux that I had got since late July 2008, to give an impression of the amount of light such a headlamp gives, but more lamps and systems have been added in due course (esp. since Summer 2010).
At that time, pictures of the Edelux in action were hard to make with the digital camera I used then, the Fuji 2600z, as it doesn't have a manual mode (ISO, F, shutter time). Nightshots in general with the 2600z are poor without flash... Since summer 2010 I used various new cameras with a setup for making beamshots of dynamo lamps. Still, the description even without beamshots gave a good idea of the properties of this lamp.
The IQ Fly was the first lamp with such a power LED that was approved for StVZO and was followed by the Schmidt Edelux. StVZO are the German traffic regulations, which contain various rules for lamps. In particular the amount of light that may go above to horizon is very limited and this is a good thing as you can read in my review of esp. the Magicshine MJ-808 which has a symmetric beam and which under some circumstances really blinds oncoming traffic. The IQ Fly suffers from a few problems, the first being that of extreme ugliness ;-) The second that its LED is not cooled properly in the plastic housing (and that reduces the light output as LEDs give more light when they are cooler). The Edelux suffers from neither of those problems... The IQ Fly (2007) and Schmidt Edelux (2008) gave huge jumps in light output that made all halogen headlamps obsolete and finally made it possible to cycle safely at a high speed (30 km/h and more) on unlit- or parallel roads.
2011-7-27: As I told those who in 2008 wanted to wait with buying an Edelux because of the LED lightput increases they expected, a jump in light output just couldn't be expected any more, and that turned out to be correct. The reason was simple: Huge jumps had already been made in the light output of 'white' LEDs and similar improvements couldn't be expected in short term because LEDs are already fairly efficient (getting to about 30% of the theoretical maximum) which eliminates large jumps. Another reason is that the eye doesn't work linearly (a lamp must produce much more light on the same area to appear to be noticeably brighter). This is why as of mid 2011 there still aren't dynamo lamps that are really better than the Edelux. A factor that has helped the Edelux stay on top is the limitations of StVZO, in particular the 2.4W at 15km/h requirement (6Veff via dynamo), and that newer LEDs such as the XP-G and XM-L have a larger illuminating area which makes it hard to bundle the light with a reflector or lens. In the future more light will primarily come from going around the limitations in StVZO, for example by gaming the system or by not adhering at all to the rules of power output. For more information on that see my StVZO analysis page.
This section is the result of all experiences I had and the tests I did with dynamos and lamps. I would like to see the following:
See also: Vibrations caused by dynamo hubs
I like the Sunup rear-wheel generator but it should produce a bit more power at low speed. This was planned for 2012, was delayed and then they created the Maxidyn with USB output, but I don't know how much power it produces at low speed. Further I would like to see more mounting options as I suggested to them (see my review of the Sunup DS)...
I would also like to see a generator that uses the brakedisc, e.g. with a special brakedisc with holes to mount neodymium magnets in, or perhaps just make a ring with magnets that attaches to the brakedisc. Then use a generator with a claw to extract power. This would be cool, but not new btw. The first Dutch bicycle computer, the IKU Cyclotronic from the 1980s used a magnet ring mounted on the front wheel both to count ticks for speed, and to generate power. It never needed a new battery... My dad bought one long ago, and I used it for years too (I still have it and it still works, see here).
2016-1-19: So, these ideas and wishes are mostly more than 5 years old now, and there is one thing I really don't like about small newer dynamo hubs from SP and Schmidt: Inability to service them: If water gets into them, you not only lose the hub but the dynamo. I wanted a modular system, something like the IKU cyclotronic but with stronger magnets (and coils on both sides), which can be made fully enclosed, no parts ever open to water coming in! Another option is the same disc, but using that disc as a sort of magnetic clutch, similar to what pool pumps use. So the dynamo could be similar to a sidewall dynamo, but with a 'wheel' with magnets, that turns because of the turning of the ring of magnets. This dynamo can be fully enclosed, nothing touching as opposed to what happens with gears, which means no noise. It can also be placed higher than a hub dynamo, so almost no chance of any problems.
I see faults and possibilities to improve designs in all products I encounter. A number of my ideas and wishes are are decribed above, though not in detail. I would also like to see a completely modular lighting system where the headlamp and taillamp contain no electronics...
I give some manufacturers suggestions for improvements as well. Whether they use those is yet to be seen, but some give positive response to them. But I really want to do more, and I'm thinking of designing a reflector for a headlamp (finally started this end of 2012). The first thing I want to do this for is to see how difficult it is, using my own computer programs. I'm also thinking about a new headlamp mount and some other things. At the moment all just for fun, and theory, but perhaps more will come from it.
In some places mention is made that a beam with cutoff such as car headlamps have, and that all approved lamps for dynamos in Europe have, is better in fog as you will get blinded by a wall of light otherwise. I tested this in autumn 2009 in fairly heavy fog at night with a Schmidt Edelux and end of 2010 with a Lupine Betty 2011 and the results were clear: the output and beam shape of the lamp are not really an issue in the 'wall of light' phenomenon, the distance to your eyes of a reasonably bright light source is by far the biggest component. If that distance is about 60 cm you will not experience a wall of light. This means putting the headlamp on the handlebar is just about OK, slightly below would be my preference. See LED light colour, CRI and experiments.
Neutral white is superior to cool white and warm white under normal circumstances (dry and wet road), in fog warm white is best. Neutral white is the overall winner, and from my experiments ca. 4000K-4500K is optimal. See LED light colour, CRI and experiments.
Not considering fog, is having a lamp mounted low or high better? In early 2009 I already experimented with the Edelux comparing it at fork-crown height and at handlebar height. The results showed that for road use (not necessarily off-road), under normal conditions (no fog) it makes virtually no difference. Putting it higher should reflect back more light, but the difference is very small and I didn't really notice it (perhaps if I put them side by side I would). You can find recommendations for a lamp positioned low in various places, as this will give more shadows so you can actually see things (rocks, whatever) better. I'm not too sure it matters, it didn't really show in my tests... I have not experimented with a lamp positioned lower than fork-crown height (as is sometimes done on bicycles with a front rack).
So all in all, I recommend a lamp positioned at fork-crown height. Update (August 2010): After testing the Philips LED bike light, for more powerful headlamps handlebar height is a bit better as it lights up the road better, but to prevent problems in fog, perhaps mounting it just below the handlebar is the optimum height for such powerful lamps. I've yet to test the Philips LED bike light in the fog to see what happens.
About 0.60x - 0.70x of the light gets onto the road, or more accurately on spots below the horizon (which can be positions beside the actual road, and to positions very far ahead where it's not of use). The exact factor depends on how wide the beam angle is, and how far away you aim the centre of the beam, on the road. This can fairly easily be calculated with school level mathematics:
Intersect a cone (the light beam from the lamp) with a horizontal plane going through the centre of the lamp's front glass and the horizon; integrate to the get the area below the line which is the intersection of one of the cone's circles and this horizontal plane. Divide this by the circle's surface and you have the fraction of light getting on the road (or rather below the horizon). Here's a picture to make it clearer:
In the calculations where I got 0.60 to 0.70, I assumed a beam angle of ca. 10-25 degrees (total angle), a distance from the lamp to where the centre of the beam hits the ground of ca. 20 metre to 40 metre, and a mounting height of the lamp of about 1.0 m (handlebar mounted). This assumes a homogeneous light beam (even distribution of light). Note that when a lamp has a bright hotspot that shines completely on the road surface, the amount of light getting onto the road will obviously be higher than that of a homogeneous light beam.
So, a fairly large amount of light is wasted (for road use) by circular beams. But not just that: while a symmetric beam may put about 0.60 - 0.70 of its light on the road (well, more accurately on spots below the horizon, and a lot beside the actual road), that doesn't mean it's as good as a lamp with cutoff that produces the same amount of light as that 0.60 - 0.70 of the symmetric lamp. This is very clear from my comparisons of the Magicshine MJ-808 and Ktronik's triple dynamo powered XP-G with an Edelux. The Edelux is much better due to its even beam and longer throw. It's also brighter on most parts of the road that the Edelux's beam covers. The Magicshine and Triple XP-G of course light up much more beside what the Edelux lights up (but mostly in places where you don't need the light). From comparing the Edelux, Magicshine, Triple XP-G and Philips LED bike light and comparing my pictures of the latter with more pictures on the IBC forums (mtb-news.de), I estimate that a symmetric lamp must have ca. 3 to 4 times the power of an asymmetric lamp with cutoff, to light up the road as well (as useful) as that lamp with cutoff.
As to being able to see traffic signs etc., you don't need a circular beam for that, lamps such as the Edelux give plenty of spill light to light up traffic signs when aimed below the horizon.
The following pictures show, asuming the illuminated surface by the lamp is a rectangle, what happens to the beam shape of a light beam of a lamp that gets mounted at a height of 1.05 m instead of 0.75 m:
As φ1 = φ2, h1/d1 = h2/d2 = tan(φ), so d2=h2 x d1/h1, i.e. 1.4xd1. The same goes for the width of the beam, so for the surface: s2 = w2 x d2 = (h2/h1)2 x w1 x d1, so the beam is now spread over a surface that has 1.42 = 1.96 x larger area. This means the beam is only half as bright...
Now also consider what happens when rotating that lamp at 1.05 m down, such that the cutoff line is at the same position where it was at 0.75 m, and take into account that the beam doesn't start directly underneath the lamp:
To be added:
1. Discussion of shadows: Shadows are bigger (more clear for lower 'obstacles', longer) at a lower mounting height, so when the lamp is mounted at 0.75 m you get more information on the surface of the road and objects lying on the road from the shadows which are longer than when the lamp is mounted at 1.05 m.
2. Angle of reflection: I mentioned this elsewhere and I've done calculations and made some pictures, but I have not integrated it in this section yet.
What's clear from the above, that the reverse situation (putting a lamp meant for handlebar height, i.e. ca. 1.05m at 0.75m and rotating such that the cutoff is in the same position on the road) has some effects which can be very much undesireable:
After testing with the Philips LBL at 0.75 m I preferred it mounted at the original height of 1.05m...
In this case mounting a lamp meant for 0.75 m but especially 1.05 m will give a significant overexposure of the near field. I'm not sure how bad it really is. It might be better to find a way to mount the lamp higher, and in case of a enclosed trike, outside the body. As I don't ride recumbents/trikes, I cannot say much about this.
I am aware that 60 lux or more headlamps with a wide beam are not needed in most situations, but the problem is that bicycle lighting is not good enough for most situations. There are 2 cases:
So for bicycles we need either a 'being seen' low lux headlamp of which there are plenty to choose from, or a 100 lux headlamp like the LBL with a wide beam and ca. 270 lumen or more, which makes it possible to properly see everywhere. The latter does not (yet) exist in commercial dynamo lamps.
So what we need in new developments is strong headlamps that allow you to see everywhere, which means 100 lux dynamo headlamps with a beam similar to the Philips LBL, not yet-another 40 lux headlamp... I am aware that 40 lux headlamps were unheard of until the arrival of the IQ Fly, but lets be honest, before that all bicycle lighting was not adequate at all for just about any situation where you actually need to see the road! Therefore I would like to see headlamps that are good enough for all situations, as it is now technically possible! My LBL-dynamo has shown this...
2011-10-24: I got the following idea long ago when I was blinded once again by a headlamp that was not very powerful at all. It gives an argument for the use of 100 lux headlamps for use within a city, for a reason you wouldn't expect: A disadvantage of bicycle headlamps with a maximal intensity of 10-40 lux is that cyclists often set their angle badly such that opposing traffic gets the maximum of the lightintensity of that beam into their eyes. If the light beam had been stronger, they would more quickly set the angle correctly because with beams of 10-40 lux you don't see the cutoff height very well when using it within a city...
2013-6-13: just before my recent trip at the end of April, the following happened, which reminded me of how much an issue the problem of incorrect aiming is:
I was cycling at night, saw a light a long way away, and thought: WTF is that!? A Xenon car headlamp? Why has he got his high beam on? Or is it perhaps the low beam, but the car is on an incline? Why do I see only one headlamp? Is the other obscured (e.g. by a tree)?
The lamp was many hundreds of metres away, it seemed to be non-moving, when I got closer it turned out to be a cyclist! A short time before he passed me, I could see almost nothing of the road or anything else, I was almost blinded... (this road is about 4-5 metres wide, will check the exact width). I told him that he had pointed his headlamp too high. He turned around, asked what I said, and we got talking. He just bought a new bike with a Rohloff hub and an Edelux. So no Xenon headlamp, but an Edelux pointed too high...
It was really badly blinding, I'd not done tests to see how blinding headlamps are for a long time, and it was good to be reminded of how badly blinding they can be...
If you think other lower lux headlamps don't have such problems, well, let's take the Pico (which is a problematic headlamp as from the beamshape it's hard to say whether it's aimed too high): It hasn't got such a high lux value, but luminance is also an issue, so it could be just as bad... I will do such tests in a month or 2 if I get round to it (life seems to get in the way the past year and a half, not enough time and inclination to do all tests that I want to do).
Note that all headlamps, and taillamps work equally well on a sidewall dynamo as on a dynamo hub. Even the K-tronik triple XP-G can be used with a standard dynamo.
What is apparent from my reviews, is how few good headlamps with cutoff for dynamo there were in 2010 and 2011. It got a lot better in 2013, but since then no real improvements, also because Philips quit... And even the best ones have fairly large weaknesses! We need more competition, and better headlamps! The LBL+special dynamo driver shows what's possible...
See Using a new dynamo LED driver, where I describe the future of dynamo lighting :-) E.g. running a Philips LBL on dynamo at 0.90A (yes!) and running a triple XM-L on dynamo at 0.90A (yes! 800 lumen for real).
When LED taillamps were getting standard, they had actually been possible and available in various types for far longer. What was curiously absent from LED based taillamps, was proper optics... As I wrote somewhere else on my site, it looks as if all the proper optics engineers retired, because the garbage that most LED taillamps put out (up to even 2015 there were very few good LED taillamps), is far inferior to some samples of incandescent taillamps, probably all of them were better because they had to have proper optics to make good use of the little available light that incandescent bulbs provide.
Test procedure: For the setup on the wallshots/corner shots, see Camera settings, camera height, lamp height, and roads used to make beamshots. The test procedure for taillamps was in 2011-2012 in its infancy and I needed to figure out what's needed for a proper review. This really meant doing all kinds of tests and making pictures under all kinds of circumstances. The fact that the test procedure was not yet fixed is also the reason that the criticism of some taillamps changed during the tests (in particular of the taillamps with incandescent bulb)...
2015-3-3: The issues have been clear for a long time, and there is just 1 addition to be done which I alluded to in 2013 already : A wallshot at various distances to see if there is a spot on the wall that stays the same shape and thus an indication of long distance visibility. But in the mean time, from my tests it seems that it's not that important, just about any current taillamp (not regarding single 5mm LED taillamps such as 'Frogs') can be seen at very long distances, 300m or more is no problem. So then it seems the biggest issue is visibility combined with distance estimation. For this an as large an illuminating surface as possible is needed...
To be done in the taillamp reviews:
Taillamp theory: considerations on what's good, bad and necessary.
Although my interest is in dynamo taillamps, in some cases I tested a battery version in case I couldn't get hold of the dynamo version. After that I've tested some more battery taillamps because they seem interesting and are not available in dynamo versions... Also battery powered taillamps are of interest when you want to run only the headlamp from dynamo.
Since 2014, I'm not making beamshots/wallshots of taillamps with visible annoying point sources so the newer ones of these are not in table of wallshots. Such lamps are immediately given a rating 'not recommended' and I will waste no further time on them. See Cornershots, wallshots and visibility of taillamps.
Goal 1: To see how well visible they are at various distances.
Goal 2: Determine the difference between line taillamps and taillamps with large illuminated surface w.r.t. visibility and ability to estimate distance. I tested this by comparing the Line plus and Plateo xds (with obscured point source).
Goal 3: To see how well you can estimate distance.
The results are interesting (see here) and show that an almost-collimated beam is needed for long range visibility, and for good close range visibility you need a large illuminated surface, and no bright point source!
Any taillamp in which the LED directly or via simplistic optics that don't distribute the light onto a larger re-emitting surface, shines to the rear. So, visible point sources, as these are always bad. Recent examples of more upmarket and yet probably bad (judging from product images) taillamps are the "LS 820 duo flat signal", "LS 613 duo flat", "813 trio flat", Axa Slim steady, B&M Toplight View plus. Sometimes I will decide to test a taillamp despite the impression from manufacturer images of poor optics. In any event, from 2014 on, if I find out that the optics are worthless (i.e. has an annoying point source), then I will not make beamshots of that particular taillamp as it's just not worth wasting my time on such taillamps... Of course a full review for such lamps are also out of teh question.
The developments I read about in cycling magazines in the 90s, were about tiny improvements in regular sidewall dynamos. Union for example had a trio of light weight dynamos (late 90s?), not much was said about hub dynamos... I bought one of those Union dynamos, which was really poor. It wasn't the Turbo (which has an aluminium housing), which I wanted to buy but couldn't obtain despite my attempts to order it from various stores, but a cheaper all-black plastic version. After a short while, the bearings were shot and it jammed. Another one I got under warranty to replace the defective one, had the same problem. The poor efficiency was clear from how hot it got during a short (say 30 minute) night ride... I see you can still buy it from some places: union 6509, from sjscycles. Don't buy it! Another bad experience was with a Sanyo dynamo that I tried in the late 1990s: It had a rubber wheel, and could be used on either the tyre or the rim, but in the wet or when there was snow it was worse than useless slipping on both rim and tyre...
Dynamo hubs were in existence long before that time. Sturmey Archer had one already in 1936. Sturmey even made an interesting 3 speed rear wheel with included dynamo. Why oh why were sidewall generators (always slipping in the rain, mud, snow) still being used so much until recently? I did read that the Sturmey hubs couldn't supply more than 1.8W, and had some problems with their seals, but wouldn't such a hub always be better than a sidewall dynamo?
A potential issue with dynamo hubs is feeling vibrations in the handlebar, see Vibrations and other issues with dynamo hubs for more about the vibration issue.
The following reviews are of all the dynamos I tried from ca. 2007 on. In general I would advise against any sidewall dynamo because of the problem of slipping in the rain, this despite possible vibration issues in the handlebar that you may get with a dynamo hub. If you really want a sidewall generator, the Axa HR is a good one with big wheel that doesn't slip quickly (I used it for half a year or so).
Contrary to bicycle headlamps and taillamps, good dynamos are available fairly cheaply. Even Shimano's low end hub dynamos last for years on Dutch bikes which see lots of rain and snow (but the higher end Shimano hubs have better seals and last longer...). The hub dynamos shown here are in some sense therefore all luxury products, and the most expensive ones have little advantage over the cheapest ones... That includes efficiency, because a hub with lower efficiency is not really noticeable, the loss in power is dwarfed by common effects such as resistance from headwind/tailwind/sidewind and the changes in that are far bigger than any resistance from a dynamo that you switch on/off.
Dynamo hubs have advantage of weight over spoke mounted dynamos, and rim dynamos such as the Velogical are quite good and almost as efficient as hub dynamos but they make noise and can slip. I don't consider roller dynamos worthy at all. My experiences with the Union roller dynamo showed, besides that that dynamo just wasn't reliable at all, the problem of muck getting stuck to the roller wheel which causes vibrations in the bike.
See the dynamo comparison page for power output test results with the special dynamo driver. Results with a resistor as per StVZO to follow.
Other issues: Theory (vibrations and more)
There was some effort to make other dynamos, esp. with less power, 1.5W, get accepted in Germany. This was done with StVZO+DIN 33958 instead of StVZO+TA. I don't see the point of this as we need more power, not less! These are for example the Shimano DH-1N70 and the later DHS-701 which are dynamo front hubs producing 6V 1.5W: From what I read (ca. 2011 IIRC) the intention was to lower production cost (less copper in the coils, smaller housing) so such dynamos could get used in lower priced bicycles. However these 1.5 W dynamos are not cheaper than 3W dynamos! Also you likely need a headlamp using less power as otherwise your light may not come on for a long time or until you cycle at 10 km/h or more. This expectation arises from my test of the SD-8 which is about a 1.8W dynamo in a big wheel, and the difference with a 3W dynamo is clear to see as you can read in my review. Note that taillamps are not a problem as long as you take a low power one such as the Lumiring or Line plus. Compared to SP's PV-8 the Shimano 1.5 W dynamo is heavier... All in all it doesn't seem interesting to me.
http://fahrradzukunft.de/14/neue-nabendynamos-im-test/ has a review of dynamos. There are a few issues with it. Not the measurements, but the way the article is written and how the dynamos are compared. See Tests/reviews by others of bicycle dynamos.
A long time ago I used a Specialized Preview 2.5 with 4 x AA NiCads) + Specialized Flashback taillamp (I ran it with 2x AAA NiCads). Regarding the headlamp, I found it very annoying that the lamp couldn't go for more than 45 minutes on high after a while, the battery capacity having decreased fairly quickly, and so I always needed to check if the batteries were charged enough for the ride I wanted to do (e.g. to Leiden, about 20 km), or I would have to routinely charge after each ride. I regularly had problems on long rides (45 minutes or more) with batteries that were nearly empty halfway. This meant I had to switch to low mode which was not enough to properly see the road and in some cases I had no light at all on large sections of these long rides.
This was very annoying and I eventually just mounted a dynamo and dynamo headlamp, and I converted the Flashback to run on dynamo. I used a few types of dynamos, all of which sometimes gave problems in rain or snow, esp. a Sanyo with rubber roller wheel that I bought was completely useless and I settled on an old 1980s one from my dad... Even with the occasional problem in the wet or snow, they were much less irritating than using a battery powered lamp. I like the comfort of the dynamo setup which is essentially having an always full battery.
My emphasis is on riding on-road (commuting, and daily use such as getting groceries), not off-road (mountainbike) so I need an asymmetric beam pattern in a lamp.
The tests of battery powered lamps and of lamps without cutoff are therefore for me of interest to see what's possible with bicycle lighting, and not to see which one I would want to use on a daily basis.
Some people use headlamps with symmetric beam such as the Magicshine to give proper light on the road, but there is no good reason for doing so: There are good lamps for on-road use, i.e. of high quality and having a good light output with which one can safely cycle on unlit roads at speeds of 30 km/h and more, lamps for dynamo (esp. the Edelux, although more light would be more comfortable, in particular on parallel roads) and lamps that are battery powered (esp. the Philips LBL/Saferide 80, and before that the B&M Ixon IQ which is similar to a Cyo but battery powered).
The tests with such lamps therefore were only of interest to me to see how well a symmetric beam lights up the road, and to study the differences between a symmetric beam and one with cutoff.
Tested from 2016-4-14: This is an interesting concept, a LED strip which even in the lowest brightness is already too bright, but still not as annoying as many taillamps with single red LED that don't have optics to distribute the light. It looks to be a phosphor layer not just on the LED but extended, and that glows at higher light intensity. But really you don't need this brightness, and I modified it to run at lower power which is still very bright on low and it will run this way for at least 17h. Between 17 and 19h the brightness dropped a lot but still bright enough to be vvery well visible, after ca. 19.5h the light is getting very dim and flickery, needs to be recharged. See more on the RPL 2261 review page.
I tried the Silva Trail elite which when using it within the house or in the garden lights up everything (at the highest setting) and the feeling I get is "Wow, what a huge amount of light!" (and amazing from such a small lamp!). In March 2016 I did a night ride to compare it especially with bike lamps with cutoff, in bends in the road. On the bike I could not see far with it, and here in NL normally it's barely usable because the non-cutoff light means you get almost blinded by all the retro-reflective traffic signs... I tested the Trail elite on a meandering bit of road, where the D6 and IQ-X completely fail to light up the road as you would need light close to you and wide to the left/right, and here the head mounted lamp that you can point with your head, ahead of actual turning, works well. Such lamps seem to be used by runners at night, and for that I suppose it's useful (in the right areas). For cycling too, on meandering roads, you could use it, but not as the only lamp, as throw is not far enough despite putting out far more light than most bicycle lamps... The beam is very wide and even, but no concentrated part of the beam means that throw is always going to be limited. I felt I could only see a fairly short distance with it, about 30m or so at most.
2015-8-17: A reader inquired about revolights (http://revolights.com), so here I give some comments:
I've seen something like it before, but those that I saw were meant for sideways visibility, and it was years ago. You could ('can' if still available) also program those that I saw, with patterns and text that the light would show when riding. It certainly looked cool, but is likely not legal in many countries!)
That these lamps are also "to see" is doubtful though it depends on what you need to see and how far ahead. In Germany they are definitely not legal... (no StVZO approval number = not legal, and in fact these lights would not get an approval according to StVZO/TA because the headlamp is not cutoff and then there are other beam pattern and minimal lux requirements; for the taillamp there is also a beam pattern requirement that it may not abide by (esp. straight to the rear) because of the positioning of the lamps on the rim).
Extra lights (besides the main headlamp and taillamp) are also not legal in many countries and whether the multiple separate lights can be considered one headlamp is an interesting issue in interpretation :))
Perhaps it would be interesting to try it out, I will think about it.
2016-4-10: I searched a little to find some pics and videos of those earlier products that I mentioned, and they and newer versions are still available. They are as I said more meant for sideways lighting for fun, but still, the concept is really the same and the revolights provide a subset of the patterns/colours that can be made with such systems. Here are some examples on youtube:
Monkey lights? (20 Sep 2007) Night riding with Glenn named "Glenn and his Monkey Lights" on http://davidschloss.com/revolights-review/, so perhaps this was the original?
No idea what type/brand (16 Oct 2011): bike spoke led lights with 40 patterns
Monkey light (17 Oct 2011): Night riding with the Mini Monkey Light
2016-4-10: Btw, as to light ideas, something which is not mounted on the wheels would be better in all aspects except to make out the front shape of the front wheel and rear shape of the rear wheel. LED strips with diffusers mounted on the front and rear forks would do at least as well for front/rear visibility and LED strips (again with diffuser; 2016-4-15: I will check how well they work without diffuser using the RPL 2261 as an example) could be mounted on the fenders to show the shape of the wheel (or rather of the fender, so less than half the top of the front wheel, and perhaps a little more than half of the rear wheel; would require lot of LEDs for a smooth appearance but the indication of the shape is really enough).
In the 1980s here in the Netherlands circular reflection on tyres, rims or somewhere mounted on the spokes became mandatory. I didn't like the aluminium spoke mounted reflectors (I think 3 were used to form a circular reflector similar to the reflecting stripe on the tyres) on my bike, but tyres soon became available with reflection and when you needed a new tyre, you simply got one of those.
Some rims were made with reflection stripes, I've seen stainless steel rims with them for example. They seem to last from my experiences, at least 15 years for a city bike that is kept mostly in a shed when you're at home, just like the reflection on the spoke reflectors. In any event, tyre reflection is the direction developments have gone and once the reflective layer gets loose from the tyre, the tyre is usally quite worn anyway.
Note that the regulators making these rules aren't stupid (or I should say: Not always stupid ;-) See my page on StVZO where I show some of the stupidities in StVZO!). Some people complain about such requirements, say that they are useless, but side reflection does help to see cyclists on intersections where motorists otherwise might go faster thinking no one is there. Many headlamps and taillamps don't put out much light to sides, which is why this reflection helps. It also helps from behind to see that a cyclist ahead is starting to make a turn. For this, reflection on the tyre is also better than on the rim or mounted on the spokes, as the tyres are wider, thus reflective surfaces in case of rim-reflection or spoke mounted reflection will be partly hidden.
The up-down movement of the reflectors on the pedals is very noticeable while not being too distracting nor annoying, and makes it very clear there's a cyclist ahead. This works at long range with a car's high beam or at at least ca. 50 m with a car's low beam (depending on the beam). With a good bicycle headlamp such as the Edelux you will also notice the pedal reflectors from a large distance.
Unfortunaly, many pedal types only come with bolt-on reflectors which don't have a long lifespan (because they are prone to getting knocks as they are exposed on the pedal's cage). You should install them anway... They work well because they are positioned at a low height part of the pedal cycle which means low beams and strong bicycle lights with cutoff will reflect off of them. That's why I prefer to use pedals with reflectors where possible.
The Shimano PD-T780 is an exception. This is Shimano's latest normal+SPD pedal with internal reflectors. This makes it my preferred normal+SPD pedal (it works nicely with standard shoes and with SPD shoes, and is not all that heavy). There is a newer version which should have more grip on the non-SPD side, but I used this one for a long time and it's quite good.
Apart from headlamps with built in USB (Luxos U, Luxx 70plus, nano 50 plus) there are other USB power devices, but you'd have to switch these with a headlamp if you also ride at night.
Here is an article with a list of power converters from dynamo to USB and other power supplies such as solar cells that could be of use on cycling trips:
Camera settings, camera height, lamp height, and roads used to make beamshots
See the lighting review pages for all my reviews of headlamps, taillamps and dynamos. If you just want to have a look at beam shots:
The videos on the page Videos of bicycle lamps in action are made with a relatively cheap camera the Samsung EX1 which has a bright F1.8 lens and a bigger sensor than compact cameras which makes the results it gives pretty good.
The colour usually chosen for LED bicycle lamps is cool white because that is the type of colour LED makers can produce most light output with, i.e. this is a 'bigger is better' choice, but it's more complicated than that. Neutral or warm white give better colour rendition for those colours that one sees at the edge of the paved road, and for mountain biking this means obviously a better colour rendition on the entire 'trail'. Ive been testing both with torches and LEDs mounted in a bicycle lamp. Also various experiments in fog to see how far a lamp should be from your eyes and which LED colour is better in those circumstances.
For the complete story with experiments and pictures which will give you a view of the differences of these colours and of the advantages of neutral white compared to cool white, see LED light colour, CRI and experiments.
See this page for various issues of lighting such as daytime lamps, correct adjustment of the light beam, etc.
It's not quite finished with the beam patterns though it doesn't take much time, I just need time for other things at the moment. I made pictures such as of white surface reflection on red retro-reflectors and that will be added too in due course. See My standard + law: WHS-2015
Forums are a problem in that the people there (moderators and forum abusers) want you to conform to their reality... I therefore generally don't visit forums much. I only recommend these:
If you want to critize something I wrote, feel free to send an email but I'm only interested in proper arguments, not things like "your reviews are biased because they don't agree at all with other reviews". That has nothing to do with being biased, because most other reviews are poorly done, so no wonder my conclusions differ... (2013: There is beginning to come more criticism on various websites and forums about point light sources and cool white LEDs and other matters that I've been writing about for a long time, but I don't know whether that has finally improved this year in magazines)
See for more about this, Criticism.
Further note that my views are biased in some sense, namely the situation in the Netherlands and neighbouring countries, Belgium and Germany. There are large differences in behaviour in motorists in esp. UK, USA, Australia and other countries with fewer cyclists, where cyclists are seen as occupying 'their roads'. The situation in a country influences a little bit what is acceptable as a lighting system, for example whether flashing is acceptable or not. With lots of cyclists, I would say it's not acceptable, and besides that it takes away the ability to estimate distance (and visibile indications that a cyclist may turn left/right!). A way to differentiate bike-car would be useful for large speed differences. But what besides flashing? Perhaps I should add a section on different attitudes in different countries? But even when looking at different attitudes, the design principles for good lamps remain as I described...
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Last modified: 2017-11-11