Myths and Facts About High Quality Rechargeable Lighting Systems

I added this section because there are so many myths being promulgated by individuals who are very much against the use of bright, high quality bicycle lighting systems. As these people create more myths, I'll add to this section. Some of these people are fairly desperate, and make all sorts of amusing accusations, and I include these here for your enjoyment.

Myth: It takes weeks of cobbling in a workshop to construct a rechargeable bicycle lighting system.

Fact: Once the components are acquired, it takes about one hour to construct. If you have to fabricate a brake bolt mounting bracket from aluminum flat, then add about another hour.

Myth: High quality rechargeable bicycle lighting systems are very expensive

Fact: While it is true that there are commercial systems costing hundreds of dollars, it is very simple to construct your own system for well under $100, and you can even get by for less than $50.

Myth: Dynamo systems are more reliable than battery powered systems.

Fact: Battery based systems are MUCH simpler than the dynamo systems, and hence more reliable. They’re a battery connected to a lamp. No moving parts. No slippage. No voltage regulators that waste power as they attempt to prevent bulb burnout at high speeds. No connections that are exposed to the weather (if done right). The only unreliable part of battery system is the user who forgets to charge the batteries! A properly maintained, high-end, dynamo system is no more or less reliable than a properly maintained battery powered system. The low quality dynamo systems are just as unreliable as low quality battery powered lights.

Myth: Dynamo systems are better for commuting than battery powered systems.

Fact: The actual power source is immaterial, what matters is whether or not the power source is capable of powering adequate lamps. The experts agree that a very bright rechargeable battery powered lighting system is the best system for commuting. There is one dynamo system that uses a 5W headlamp (as opposed to a 2.4-3W headlamp); this would be adequate for commuting, but it is very expensive.

Myth: LED blinkers are the best type of rear light.

Fact: LED blinkers have many drawbacks. The most serious is the narrow field of view. There are a couple of decent LED blinkers on the market, but neither is as good as a xenon strobe.

Myth: MR16 and MR11 lamps are “decorator” lamps, because they are used in some track lighting fixtures and display cases.

Fact: MR16 and MR11 lamps are used in a wide variety of scientific, consumer, and commercial products. The reason for their popularity is because the fact that the reflector and the bulb are precisely matched together. The reflector and the bulb are one unit. These lamps are popular because they provide an excellent ratio of illumination per watt. Also see The Optics Debate, below.

Myth: You’re advocating that cyclists put megawatts of lamps on their bicycles and haul around tons of batteries to power them.

Fact: The advocates of dynamo systems tend to exaggerate. No one has suggested that megawatts of lamps are necessary for cyclists.

Myth: I know that my lights are fine, because I asked someone to tell me if they could see my bike at night and they said that they could.

Fact: This is not a reliable test because the person is specifically looking for your bike.

Myth: I know that my low power lights are fine, because I've been using them for years and haven't had any problems.

Fact: This is not proof of anything. You may just be lucky. You may be exceptionally cautious. There are lots of examples of people getting away with dangerous behavior for long periods of time.

Myth: Small battery powered, and dynamo lights, meet the legal requirements for lighting so they must be fine.

Fact: The minimum legal requirements for bicycle lighting are just that, minimum legal requirements. The minimum legal requirements are inadequate, according to every expert on bicycle lighting. There is no requirement for a rear light at all, just a reflector meets the legal requirement.

Myth: LEDs make good headlights because they have a high lumens/watt ratio and because they are "solid-state" devices without "white-hot" filaments.

Fact: LEDs make lousy bicycle headlights, at least so far. The very bright 5W LEDs have a very short life, 500 hours, and run too hot for applications without active cooling. 1W LEDs have long lives, but it requires multiple 1W LEDs to achieve a reasonable intensity, and there is no good way to collimate the output of individual LEDs into a usable beam.

LEDs make reasonable "being seen" lights if you use enough of them, and use the proper reflector and lens, i.e. the Reallite 18 LED rear flasher.

While low power LEDs do have a higher lumens/watt ratio than low power quartz-halogen bulbs, they are not orders of magnitude better. LEDs are not as efficient as HID bulbs.

Myth: You must have bought cases of MR16 and MR11 lamps which you are trying to unload.

Fact: This was an amusing accusation by an intellectually-challenged Usenet poster, but no, I do not sell lamps of any kind. About twenty years ago I sold complete systems, but not with MR16 or MR11 lamps.

Myth: Dynamo lights reach their rated light output at low speeds, and hence are suitable for riding on multi-use trails with low speed limits.

Fact: See At 10km/hour, only the Dymotec S6 is at 6 volts, the others are between 4.6 and 5.2 volts. It was interesting to read the theory that dynamos are not well-suited for multi-use paths, since that seems to be counter-intuitive. When you apply the correction factor for under-voltaging, you can see where the theory came from, and it makes sense. Remember that while over-voltaging a lamp exponentially increases the light output, under-voltaging exponentially decreases it.

Myth: If you don't use a dynamo light then you're not a serious cyclist.

Fact: Another content-free Usenet post by someone who knows not of what he speaks.

Myth: Dynamo lights are better than battery powered lights because no one wants to steal them.

Fact: There are no statistics regarding the relative number of thefts of dynamo powered lights versus battery powered lights, nor are there ever likely to be any. Expensive battery powered lights are removed and taken inside when a cyclist parks in an area where they might be likely to be stolen. Furthermore, cyclists with battery powered lights are more likely to be professionals, and working in jobs where they have secure parking, or can take their bicycles into their office. Dynamos may not be an attractive item to steal, but there are reports of them being stolen. But all the evidence is anecdotal, and will remain so. Personally, I leave my battery powered lights on the bike at all times. They are not quick-release, and they are not-expensive. I could replace the three of them for less than $25. I use common sense about where I leave my bike of course.

Myth: Did you ever not see a legally lit cyclist? If not, it proves that legal lighting is sufficient.

This is the question and claim that some braniac asked on This individual has a long history of putting forth illogical premises and reaching illogical conclusions, but this one was so classic that I couldn't resist including it here.



1. This question is using the wrong sample group. Cyclists are not a good group to ask, since cyclists, even while driving, are more conscious of cyclists than the average driver.
2. Even with the right sample group, asking someone how often they didn't see something is ludicrous by definition.
3. Every expert on bicycle lighting agrees that the typical state's minimum legal lighting standards are too low. Most states don't even require a tail light. The legal standards have evolved over time from the capability of the old-time dynamo lighting sets; they are not based on what level illumination actually provides sufficient visibility.

Myth: The only time you need the very top of the watt range is going downhill. Anyone can coast down a hill.


Fact:  This was a claim based on the fact that dynamos can output greater than their rated output power at higher speeds. It is possible to connect two 3W lamps to a 3W dynamo and have both powered at full brightness if they dynamo is spinning fast enough. I have no idea where this individual got the idea that the full brightness is only needed when traveling down a hill. This is one of the more amusing myths that anyone has come up with.

Myth: Battery powered lights require 'pratting around with charging batteries all the time'


Fact:  This was in response to someone that posted that one big advantage of battery powered lights is that they are easily moved from bicycle to bicycle, versus spending hundreds of dollars per bicycle on dynamo hubs and lamps. It's a myth because charging your battery powered light is no more difficult that charging your cell phone. It does not require a Herculean effort to connect a charger.

Myth: "Everyone (who doesn't use one) complains that dynamos slow you down."


Fact:  Hmm, not sure where to go with this gem. Clearly our educational system has failed to teach critical thinking skills when people make statements like this. I do use one (a bottle dynamo) so I guess I can legitimately state that they slow me down, even though it's not really a complaint. Maybe what he's trying to say is that they do slow you down, but only people that don't use them complain about it, while people that do use them aren't complaining about going slower.


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